KS0470 4WD BT Multi-purpose Smart Car V2.0 Kit Mixly Tutorial

1. Introduction

Nowadays, technological education such as VR, kids programming, and artificial intelligence, has become mainstream in educational industry. Thereby, people attach importance to STEAM education.

The 4WD multi-purpose robot car, newly upgraded by the Keyes team, is one of the most favoured programming robots.

It is not only beautiful in appearance, but also powerful in function. In addition to the common function like line tracking, obstacle avoidance and remote control, etc.

15 learning projects, from simple to complex, will guide you how to make a smart 4wd robot on you own and introduce the detailed knowledge about sensors and modules.

Simultaneously, it is the best choice if you intend to obtain a DIY robot for learning programming, entertainment and competition requirement.

Note: The experiment you did should be in line with wiring diagram, including about components and wiring method. For example, we supply power with external power in the hook-up diagram, so you also have to use external power rather than USB cable.

2. Features

  1. Multi-purpose function: Obstacle avoidance, follow, IR remote control, Bluetooth control, ultrasonic follow and displayed face emoticons.

  2. Simple assembly: No soldering circuit required, complete assembly easily.

  3. High Tenacity: Aluminum alloy bracket, metal motors, high quality wheels and tracks

  4. High extension: expand other sensors and modules through motor driver shield and sensor shield

  5. Multiple controls: IR remote control, App control(IOS and Android system)

  6. Basic programming： Mixly programming.

3. Specification

Working voltage: 5v

Input voltage: 7-12V

Maximum output current: 2A

Maximum power dissipation: 25W (T=75℃)

Motor speed: 5V 200 rpm/min

Motor drive mode: dual H bridge drive

Ultrasonic induction angle: <15 degrees

Ultrasonic detection distance: 2cm-400cm

Infrared remote control distance: 10 meters (measured)

Bluetooth remote control distance: 50 meters (measured)

Bluetooth control: support Android and iOS system

4. Product List

No

Name

QTY

Picture

1

Keyestudio V4.0 Board

1

2

Keyestudio Motor Driver Shield

1

3

Keyestudio HM-10 Bluetooth-4.0

1

4

Red LED Module

1

5

HC-SR04 Ultrasonic Sensor

1

6

Keyestudio Line Tracking Sensor

1

7

Keyestudio IR Receiver Sensor

1

8

Keyestudio 8*16 LED Dot Matrix

1

4pinDupont Line

9

Keyestudio 9G Servo

1

10

Keyestudio Remote Control

1

11

USB Cable

1

12

18650 Battery Holder

1

13

6 AA Battery Holder

1

14

Servo Platform

1

15

15CM F-F 5P 24AWG Dupont Wire

1

16

8cm F-F 3P 24AWG Dupont Wire

1

17

4P to 1P Female DuPont Wire

1

18

Acrylic Board

1

19

Keyestudio 4WD Smart Car V2.0 Top Board

1

20

Keyestudio 4WD Smart Car V2.0 Bottom PCB

1

21

Fixed Parts

4

22

Wheel

4

23

M3*10MM Dual-pass Copper Bush

10

24

M3*40MM Dual-pass Copper Bush

4

25

M3*30MM Round Head Screws

8

26

M3*6MM Round Head Screws

40

27

M3 Nickel Plated Nuts

16

28

M2X8MM Round Head Screws

6

29

M3*8MM Round Head Screws

4

30

M2 Nickel Plated Nuts

6

31

M3*10MM Flat Screws

3

32

Motor (with welding wire)

4

33

3*40MM Screwdriver

1

34

Black Nylon Ties 3*100MM

6

35

Winding Pipe

1

36

3Pin F-F Dupont Wire (20CM)

3

37

Decorative Board

5. Assembly Guide

Note: Peel the plastic film off the board first when installing the smart car. To be honest, we never intend to send wood to you.

Mount the Bottom PCB

  • Prepare the parts as follows:

Gear Motor *4

Fixed Part *4

M3 Nickel Plated Nut *10

M3*6mm Round Head Screw *14

4WD Bottom PCB *1

Tracking Sensor *1

Wheel *4

5P Dupont Wire *1

M3*40mm Copper Pillar*6

M3*30m Round Head Screw *8

M3*8mm Round Head Screw *2

Install Dot Matrix

  • Prepare the parts as follows:

8X16 LED Panel *1

4WD Baffle

4P Wire *1

M2*8mm Round Head Screw *4

M2 Nut *4

Install the Plastic Platform of Servo

  • Prepare the parts as follows:

Servo *1

M2*4 Screw *1

Black Cable Tie*2

Ultrasonic Sensor*1

Black Plastic Platform *1

M1.2*4 Tapping Screw *4

M2*8 Tapping Screw *2

Assemble Battery Holder

  • Prepare the parts as follows:

Top PCB *1

M3 Nut *3

Motor Driver Board *1

Control Board *1

IR Receiver Module *1

M3*10mm Copper Pillar *8

M3*8mm Round Head Screw *1

M3*6mm Round Head Screw *16

M3*10mm Flat Screw *2

6 AA Battery Holder *1

Mount the Top PCB

  • Prepare the parts as follows:

Bluetooth Module *1

M3*6MM Round Head Screw *6

Jumper Cap*8

6.Hook-up Guide

6.Install Mixly Software and Driver

Download and Install Mixly

Description

Mixly is a free open-source graphical Arduino programming software, based on Google’s Blockly graphical programming framework, and developed by Mixly Team@ BNU.

It is a complete support ecosystem for creative e-education, a stage for maker educators to realize their dreams.

Download Mixly1.0

Windows System：https://fs.keyestudio.com/Mixly1-Windows

MACOS System：https://fs.keyestudio.com/Mixly1-MACOS

We will take Mixly1.0 (Windows version) as example, and the installation method of MAC version is similar with it.

You will get installation package after downloading. As shown below:

Unzip the package, you will see “Mixly 1.0 for keyestudio.exe”

Double-click ”Mixly 1.0 for keyestudio.exe”, the following interface pops up.

We have to choose correct Arduino development board and name, as shown below:

Select correct COM port(the corresponding port will be shown after installing driver successfully)

You have to know the function of every area and interface on Mixly software before uploading program on Arduino development board.

Keyestudio V4.0 Development Board

We need to know keyestudio V4.0 development board, as a core of this smart car.

Keyestudio V4.0 development board is an Arduino uno -compatible board, which is based on ATmega328P MCU, and with a cp2102 Chip as a UART-to-USB converter.

It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, 2 ICSP headers and a reset button.

It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it via an external DC power jack (DC 7-12V) or via female headers Vin/ GND(DC 7-12V) to get started.

Microcontroller

ATmega328P-PU

Operating Voltage

5V

Input Voltage (recommended)

DC7-12V

Digital I/O Pins

14 (D0-D13) (of which 6 provide PWM output)

PWM Digital I/O Pins

6 (D3, D5, D6, D9, D10, D11)

Analog Input Pins

6 (A0-A5)

DC Current per I/O Pin

20 mA

DC Current for 3.3V Pin

50 mA

Flash Memory

32 KB (ATmega328P-PU) of which 0.5 KB used by bootloader

SRAM

2 KB (ATmega328P-PU)

EEPROM

1 KB (ATmega328P-PU)

Clock Speed

16 MHz

LED_BUILTIN

D13

Installing V4.0 board Driver

Let’s install the driver of keyestudio V4.0 board. The USB-TTL chip on V4.0 board adopts CP2102 serial chip. The driver program of this chip is included in Arduino 1.8 version and above, which is convenient. Plug on USB port of board, the computer can recognize the hardware and automatically install the driver of CP2102.

If install unsuccessfully, or you intend to install manually, open the device manager of computer. Right click Computer—– Properties—– Device Manager.

There is a yellow exclamation mark on the page, which implies installing unsuccessfully. Then we double click the hardware and update the driver.

Click “OK” to enter the following page, click “browse my computer for updated driver software”, find out the installed or downloaded ARDUINO software. As shown below:

There is a DRIVERS folder in Arduino software installed package, open driver folder and you can see the driver of CP210X series chips.

We click “Browse”, then find out the driver folder, or you could enter “driver” to search in rectangular box, then click “next”, the driver will be installed successfully. (I place Arduino software folder on the desktop, you could follow my way)

Open device manager, we will find the yellow exclamation mark disappear. The driver of CP2102 is installed successfully.

Start the first program

Click “Open”→ sample → arduino→ Arduino → 01 IN-OUT→01-LED Blink.mix

The corresponding board and COM port will be shown after setting board and COM port.

Click Compile to start compiling the program, check errors.

Click Upload to upload the program, upload successfully.

After uploading the program successfully, the onboard LED lights up for 1s, lights off for 1s. Congratulation, you finish the first program.

7. Projects：

The whole project begins with basic program. Starting from simple to complex, the lessons will guide you to assemble robot car and absorb the knowledge of electronic and machinery step by step. I reckon that you could hardly sit still and itch to have a go, let’s get started.

Note: (G), marked on each sensor and module, implies negative pole, which is connected to “G”, ”-”or “GND”on the sensor shield and control board ; (V) represents positive pole, which is linked with V , VCC, + or 5V on the sensor shield and control board.

Project 2: Adjust LED Brightness

1 Description

In previous lesson, we control LED on and off and make it blink.

In this project, we will control LED brightness through PWM to simulate breathing effect. Similarly, you can change the step length and delay time in the code so as to demonstrate different breathing effect.

PWM is a means of controlling the analog output via digital means. Digital control is used to generate square waves with different duty cycles (a signal that constantly switches between high and low levels) to control the analog output.In general, the input voltage of port are 0V and 5V. What if the 3V is required? Or what if switch among 1V, 3V and 3.5V? We can’t change resistor constantly. For this situation, we need to control by PWM.

For the Arduino digital port voltage output, there are only LOW and HIGH, which correspond to the voltage output of 0V and 5V. You can define LOW as 0 and HIGH as 1, and let the Arduino output five hundred 0 or 1 signals within 1 second.

If output five hundred 1, that is 5V; if all of which is 1, that is 0V. If output 010101010101 in this way then the output port is 2.5V, which is like showing movie. The movie we watch are not completely continuous. It actually outputs 25 pictures per second. In this case, the human can’t tell it, neither does PWM. If want different voltage, need to control the ratio of 0 and 1. The more 0,1 signals output per unit time, the more accurately control.

PWM is a technology to obtain analog quantity through digital method. Digital control forms a square wave, and the square wave signal only has two states of turning on and off (that is, high or low levels). By controlling the ratio of the duration of turning on and off, a voltage varying from 0 to 5V can be simulated. The time turning on(academically referred to as high level) is called pulse width, so PWM is also called pulse width modulation.

Through the following five square waves, let’s acknowledge more about PWM.

In the above figure, the green line represents a period, and value of analogWrite() corresponds to a percentage which is called Duty Cycle as well. Duty cycle implies that high-level duration is divided by low-level duration in a cycle. From top to bottom, the duty cycle of first square wave is 0% and its corresponding value is 0. The LED brightness is lowest, that is, turn off. The more time high level lasts, the brighter the LED. Therefore, the last duty cycle is 100%, which correspond to 255, LED is brightest. 25% means darker.

PWM mostly is used for adjusting the LED brightness or rotation speed of motor.

It plays vital role in controlling smart robot car. I believe that you can’t wait to enter next project.

2 Components

3 Test Code：

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_2_Adjust LED Brightness

lesson_2.1_Adjust LED Brightness

You could edit code step by step as follows:

  1. Click “Control” to get block

  2. Go to“sensor”→“ControlOutput”→.

  3. Red LED is connected to D3, so set to PIN 3 and LOW.

  4. Enter“Control”to get block，set block:

  5. Enter “In/Out” to get block.

  6. Click “Variables” to move blockinto 0 box behind value.

  7. Click ”Control”to move blockinto block，delay in 5ms.

  8. Copy code stringonce，set code string as follows:

Complete Program：

4. Test Result

Upload test code successfully, LED gradually becomes brighter then darker, like human breath, rather than light on and off immediately.

5. Extension Practice

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_2_Adjust LED Brightness

lesson_2.2_Extension Practice

You could edit code step by step as follows:

Complete Program：

Upload code on the development board and the time interval of LED getting dark is longer.

Project 3 : The working Principle of Line Tracking Sensor

（1）Description：

The tracking sensor is actually an infrared sensor. The component used here is the TCRT5000 infrared tube.

Its working principle is to use the different reflectivity of infrared light to the color, then convert the strength of the reflected signal into a current signal.

During the process of detection, black is active at HIGH level, but white is active at LOW level. The detection height is 0-3 cm.

Keyestudio 3-channel line tracking module has integrated 3 sets of TCRT5000 infrared tube on a single board, which is more convenient for wiring and control.

By rotating the adjustable potentiometer on the sensor, it can adjust the detection sensitivity of the sensor.

（2）Specification：

  • Operating Voltage: 3.3-5V (DC)

  • Interface: 5PIN

  • Output Signal: Digital signal

  • Detection Height: 0-3 cm

Special note: before testing, turn the potentiometer on the sensor to adjust the detection sensitivity. When adjust the LED at the threshold between ON and OFF, the sensitivity is the best.

（3）Equipment：

（4）Connection Diagram：

（5）Test Code：

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_3_Line Tracking Sensor

lesson_3.1_Line Tracking Sensor

You could edit code step by step as follows:

  1. Click “Control” to get block.

  2. Enter “Serial port” to move blockimgintoimgblock.

  1. Go to “Variables” to moveinto blockfor three times；then enter “Math” to drag block and copy it for 3 times.

  2. Combine withblock, and separately set to val_L, val_M and val_R.

  1. Enter “Variables” to move out block，

  2. Go to “Sensor” → “DigitalRead”→

  3. Integrate blockimgwithimgblock.

  4. The line tracking sensor is linked with D6, so set to PIN 6.

  5. Replicate blocktwice，and separately change val_L into val_M and val_R;

  6. The tracking sensor is also connected to D7 and D8, therefore, set to PIN 7 and PIN 8.

  7. Click “Serial Port”to drag out block，and go to “Text” to move blockinto block.

  8. Change hello into left：img+img=img

  9. Copy blockagain，and enter“Variables”to moveimage-20230614113523462 block.

  10. Replicate code once and delete left， as shown below:

  11. Duplicate code stringonce，and change left：into middle : , val_L into val_M.

  12. Copy block，and alter left：into right：

  13. Go to“Serial Port”to drag outblock ，and enter “Variables” to drag into block.

  14. Enter “Control” to get block, and delay in 500ms.

Complete Program：

（6）Test Result：

Upload the code on development board, open serial monitor to check line tracking sensors. And the displayed value is 1(high level) when no signals are received. The value becomes int o 0 when covering sensor with paper.

（7）Extension Practice：

After knowing its working principle, connect an LED to D9. We could control LED by line tracking sensor.

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_3_Line Tracking Sensor

lesson_3.1_Extension Practice

You could edit code step by step as follows:

Click “Control” to get block

Enter “Serial Port” to move blockimgintoimg

img+ img= img

Go to “Variables” to drag out blockand copy it twice.

Separately change item into val_L, val_M and val_R.

Go to “Math” to move out blockand replicate it twice.

Edit code string as follows:

  1. Go to “Variables” to drag out block.

  2. Then click “Sensor” → “DigitalRead”→

  3. Move blockimgintoimgblock.

  4. The line tracking sensor is linked with D6, so set to PIN 6.

  5. Replicate blocktwice，and separately change val_L into val_M and val_R;

  6. The tracking sensor is also connected to D7 and D8, therefore, set to PIN 7 and PIN 8

  7. Click “Serial Port” to drag out block，and go to “Text” to move blockinto block，

  8. Change hello into left：img+img=img

  9. Copy blockagain，and enter“Variables”to moveimage-20230614114755929 block.

  10. Replicate code once and delete left, as shown below:

  11. Duplicate code stringonce，and change left：into middle : , val_L into val_M.

  12. Copy block，and alter left：into right：

  13. Go to“Serial Port”to drag outblock ，and enter “Variables” to drag into block.

  14. Enter“Control”to move out blockimg，clickimgto move blockimgintoimgblock，thenimgblock turns intoimg.

  15. Go to “Logic” to move blockinto if block.

  16. Enter “Variables” to drag blockinto the left box of block“=”，click “Math” to move blockinto right box of“=”，and change 0 into 1.

  17. Go to “sensor” → “ControlOutput” →

  18. Place it into do block，and set to LOW

  19. LED is linked with D3，therefore, set to PIN 3.

  20. Copy blockagain and keep it into else

  21. Then set to HIGH, click ”Control” to move out block，and delay in 2000ms.

  22. Replicate code stringtwice，and respectively set to val_M and val_R.

Complete Program：

Upload the code to development board, we could see LED light up when covering the line tracking sensor by hand.

Project 4: Servo Control

1. Description

Servo motor is a position control rotary actuator. It mainly consists of housing, circuit board, core-less motor, gear and position sensor. Its working principle is that the servo receives the signal sent by MCU or receiver and produces a reference signal with a period of 20ms and width of 1.5ms, then compares the acquired DC bias voltage to the voltage of the potentiometer and the voltage difference output.

When the motor speed is constant, the potentiometer is driven to rotate through the cascade reduction gear, which leads that the voltage difference is 0, and the motor stops rotating. Generally, the angle range of servo rotation is 0° -180 °.

The rotation angle of servo motor is controlled by regulating the duty cycle of PWM (Pulse-Width Modulation) signal. The standard cycle of PWM signal is 20ms(50Hz). Theoretically, the width is distributed between 1ms-2ms, but in fact, it’s between 0.5ms-2.5ms. The width corresponds the rotation angle from 0° to 180°. But note that for different brand motor, the same signal may have different rotation angle.

The corresponding servo angles are shown below:

2. Specification

Working voltage: DC 4.8V ~ 6V

Operating angle range: about 180 ° (at 500 → 2500 μsec)

Pulse width range: 500 → 2500 μsec

No-load speed: 0.12 ± 0.01 sec / 60 (DC 4.8V) 0.1 ± 0.01 sec / 60 (DC 6V)

No-load current: 200 ± 20mA (DC 4.8V) 220 ± 20mA (DC 6V)

Stopping torque: 1.3 ± 0.01kg · cm (DC 4.8V) 1.5 ± 0.1kg · cm (DC 6V)

Stop current: ≦ 850mA (DC 4.8V) ≦ 1000mA (DC 6V)

Standby current: 3 ± 1mA (DC 4.8V) 4 ± 1mA (DC 6V)

3. Equipment：

4. Wiring Diagram：

Wiring note: the brown line of servo is linked with Gnd(G), the red line is connected to 5v(V) and orange line is attached to digital 10.

The servo has to be connected to external power due to its high demand for driving servo current. Generally, the current of development board is not enough. If without connected power, the development board could be burnt.

5. Test Code：

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_4_Servo Control

lesson_4_Servo Control

You could edit code step by step as follows:

  1. Go to“Control”to get block

  2. Enter “Module”→“Drive_Module”to get blockand place it into block，

  3. The servo is linked with D10, so set to PIN 10.

  4. Set servo to 90°，and delay in 500ms.

Replicate code string for three times，respectively change 90 into 0, 180 and 0

Complete Program：

6. Test Result：

Upload code successfully and power on, servo swings in the range of 0° to 180°.

Project 5: Ultrasonic Sensor

1 Description

The HC-SR04 ultrasonic sensor uses sonar to determine distance to an object like bats do. It offers excellent non-contact range detection with high accuracy and stable readings in an easy-to-use package. It comes complete with ultrasonic transmitter and receiver modules.

The HC-SR04 or the ultrasonic sensor is being used in a wide range of electronics projects for creating obstacle detection and distance measuring application as well as various other applications. Here we have brought the simple method to measure the distance with arduino and ultrasonic sensor and how to use ultrasonic sensor wit h arduino.

2. Specification

Power Supply :+5V DC

Quiescent Current : <2mA

Working Current: 15mA

Effectual Angle: <15°

Ranging Distance : 2cm – 400 cm

Resolution : 0.3 cm

Measuring Angle: 30 degree

Trigger Input Pulse width: 10uS

3. Equipment：

4. Ultrasonic Sensor

As the above picture shown, it is like two eyes. One is transmitting end, the other is receiving end.

The ultrasonic module will emit the ultrasonic waves after trigger signal. When the ultrasonic waves encounter the object and are reflected back, the module outputs an echo signal, so it can determine the distance of object from the time difference between trigger signal and echo signal.

The t is the time that emitting signal meets obstacle and returns, and the propagation speed of sound in the air is about 343m/s, therefore, distance = speed * time, because the ultrasonic wave emits and comes back, which is 2 times of distance, so it needs to be divided by 2, the distance measured by ultrasonic wave = (speed * time)/2

  1. Use method and timing chart of ultrasonic module:

  2. Setting the delay time of Trig pin of SR04 to 10μs at least, which can trigger it to detect distance.

  3. After triggering, the module will automatically send eight 40KHz ultrasonic pulses and detect whether there is a signal return. This step will be completed automatically by the module.

  4. If the signal returns, the Echo pin will output a high level, and the duration of the high level is the time from the transmission of the ultrasonic wave to the return.

    image-20230614115617652

Circuit diagram of ultrasonic sensor:

5. Hook-up Diagram：

Wiring guide:

Ultrasonic sensor keyestudio V5 sensor shield

VCC → 5v(V)

Trig → 12(S)

Echo → 13(S)

Gnd → Gnd(G)

6. Test Code：

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_5_Ultrasonic Sensor

lesson_5.1_Ultrasonic Sensor

You could edit code step by step as follows:

  1. Click “Control” Module to get block.

  2. Enter “Serial Port” to move blockimgintoimgblock.

​ img

  1. Go to “Variables” to get blockand copy it twice. Respectively change item into distance 1 and distance 2.

  2. Click “Math” to move out blockand replicate it twice.

  1. Click “Variables” to drag out block，and enter “sensor” → “OtherSensor” →.

  2. Combine block with block，

  3. Trig pin of ultrasonic sensor is connected to D12(S) of shield，Echo is attached to D13(S)，so set Trig 12 and Echo 13.

  1. Click “Variables” to get block，and drag out from “Math” and keep it behind block.

  2. Go to “Variables” to move out blockleft 1 box“.

  3. Then change another 1 into 0.3937，and set to “×”.

  1. Go to “Serial Port ” to drag out block，and click “Variables” to get block.

  2. Combine with

  1. Go to “Serial Port” to get block，then click “Text” module to drag block，and change hello into in.

  1. Copy code stringonce，change distance2 into distance1，in into cm

  1. Click “Control” to get block，delay in 50ms.

Complete Program：

7. Test Result：

Upload test code on the development board, open serial monitor and set baud rate to 9600. The detected distance will be displayed, unit is cm and inch. Hinder the ultrasonic sensor by hand, the displayed distance value gets smaller.

8. Extension Practice：

We have measured the distance displayed by ultrasonic sensor. How about controlling the LED with the measured distance? Let’s try it, connect an LED light module to the D3 pin.

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_5_Ultrasonic Sensor

lesson_5.2_Extension Practice

You could edit code step by step as follows:

  1. Enter “Control” to get block

  2. Click “Serial Port” to drag out block

  1. Go to “Variables” to move out blockand copy it twice.

  2. Enter “Math” to drag out blockand replicate twice, and change item into distance 1 and distance 2.

  3. Edit the code string as follows:

  1. Go to “Variables” to move outblock，then click“sensor”→“OtherSensor” →

  2. Combine it with block，the pin Trig of ultrasonic sensor is linked with D12(S) of expansion board, pin Echo is attached to D13(S); therefore, click the triangle button to select 12 and 13.

  1. Click “Variables” to get block，and drag out from “Math” and keep it behind block.

  2. Go to “Variables” to move out blockleft 1 box“. Then change another 1 into 0.3937，and set to “×”.

  1. Go to “Serial Port ” to drag out block，and click “Variables” to get block.

  2. Combine with

  1. Go to “Serial Port” to get block，then click “Text” module to drag block ，and change hello into in.

  1. Replicate code string once，and change distance2 into distance1，and in into cm.

  1. Go to“Control”to move out blockand delay in 50ms

  1. Click “Control” and drag it into blockand movethen we get block.

  2. Go to “Logic” to get and .

  3. Place into if block，and leave in the left box of block.

  4. Enter “Variables” to get block and keep it at left box of block “=”.

  5. Go to “Math” to move outinto right box of block “=”，and change 0 into 2, “=” into “≥”.

  6. Replicate blockonce and set

  1. Click “sensor”→“ControlOutput”→and place it into do block，

  2. The S end of LED Module is connected to D3 of expansion board，therefore, click the triangle button to select 9.

  3. Replicate blockonce and leave it into “else” and set to LOW.

Complete Program：

Upload test code to development board and block ultrasonic sensor by hand, then check if LED is on

Project 6: IR Reception

1 Description

There is no doubt that infrared remote control is ubiquitous in daily life. It is used to control various household appliances, such as TVs, stereos, video recorders and satellite signal receivers. Infrared remote control is composed of infrared transmitting and infrared receiving systems, that is, an infrared remote control and infrared receiving module and a single-chip microcomputer capable of decoding.​

The 38K infrared carrier signal emitted by remote controller is encoded by the encoding chip in the remote controller. It is composed of a section of pilot code, user code, user inverse code, data code, and data inverse code. The time interval of the pulse is used to distinguish whether it is a 0 or 1 signal and the encoding is made up of these 0, 1 signals.

The user code of the same remote control is unchanged. The data code can distinguish the key.

When the remote control button is pressed, the remote control sends out an infrared carrier signal. When the IR receiver receives the signal, the program will decode the carrier signal and determines which key is pressed. The MCU decodes the received 01 signal, thereby judging what key is pressed by the remote control.

Infrared receiver we use is an infrared receiver module. Mainly composed of an infrared receiver head, it is a device that integrates reception, amplification, and demodulation. Its internal IC has completed demodulation, and can achieve from infrared reception to output and be compatible with TTL signals. Additionally, it is suitable for infrared remote control and infrared data transmission. The infrared receiving module made by the receiver has only three pins, signal line, VCC and GND. It is very convenient to communicate with arduino and other microcontrollers.

2 Specification

Operating Voltage: 3.3-5V（DC）

Interface: 3PIN

Output Signal: Digital signal

Receiving Angle: 90 degrees

Frequency: 38khz

Receiving Distance: 10m

3 Equipment：

4 Connection Diagram

Respectively link “-”, “+” and S of IR receiver module with G(GND）, V（VCC）and A0 of keyestudio development board.

Attention: On the condition that digital ports are not available, analog ports can be regarded as digital ports. A0 equals to D14, A1 is equivalent to digital 15.

5 Test Code：

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_6_IR Reception

lesson_6.1_IR Reception

You could edit code step by step as follows:

  1. Enter “Control” Module to get block.

  2. Click“Serial Port”Module to drag blockblock:

  3. Go to “Module”→”Communicate_Module”→，

  4. Signal end of IR receiver module is connected to A0 of shield, therefore, click triangle button to select 3.

  1. Click “Control” Module，to moveout, delay in 100ms

Complete Program：

6. Test Result：

Upload test code, open serial monitor and set baud rate to 9600, point remote control to IR receiver and the corresponding value will be shown, if pressing so long, the error codes will appear

Below we have listed out each button value of keyestudio remote control. So you can keep it for reference.

7 Extension Practice:

We decoded the key value of IR remote control. How about controlling LED by the measured value? We could operate an experiment to affirm. Attach an LED to D3, then press the keys of remote control to make LED light up and off.

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_6_IR Reception

lesson_6.2_Extension Practice

You could edit code step by step as follows:

  1. Enter “Control” Module to get block

  2. Go to “Serial Port” to move out blockinto block:

  3. Go to “Module”→“Communicate_Module”→，

  4. S end of IR receiver module is linked with 3. therefore, click triangle button to set A0.

  1. Go to “Variables” to move blockinto block，(6) Go to“Math”to drag out blockand integrate with, then change item into a:

  2. Click “Control”module to get blockturns intoblock.

  3. Go to “Logic”，and find out block. Leave it behind if block

  4. Go to “Logic” to placein the left box.

  5. Click “Variables” to move in the left box of “=” block，go to “Math” to drag outinto right box of “=”，then change 0 into 0xFF02FD.

  6. Copyonce and keep it into right box of ”and” block，change ir_item into a，0xFF02FD into 0.

  1. Click “sensor”→ “ControlOutput”→

  2. Keep it into the first do block，S end of red LED module is linked with D3 of expansion board，and set to Pin 3.

  3. Go to “Variables” to movebelow “Red_LED…HIGH” block.

  4. Click “Math” to get block into，and change 0 into 1:

  5. Replicate once and move into “else if” ，change 0 into 1.

  6. Replicate code stringonce and place it into second do block.

  7. Click “HIGH” into “LOW”，1 into 0:

Complete Program：

Upload code to development board, press “OK” key on remote control to make LED on and off.

Project 7: Bluetooth Remote Control

1.Description：

Bluetooth, a simple wireless communication module most popular since the last few decades and easy to use are being used in most of the battery-powered devices.

Over the years, there have been many upgrades of Bluetooth standard to keep fulfil the demand of customers and technology according to the need of time and situation.

Over the few years, there are many things changed including data transmission rate, power consumption with wearable and IoT Devices and Security System.

Here we are going to learn about HM-10 BLE 4.0 with Arduino Board. The HM-10 is a readily available Bluetooth 4.0 module. This module is used for establishing wireless data communication. The module is designed by using the Texas Instruments CC2540 or CC2541 Bluetooth low energy (BLE) System on Chip (SoC).

2.Parameters:

Bluetooth protocol: Bluetooth Specification V4.0 BLE

No byte limit in serial port Transceiving

In open environment, realize 100m ultra-distance communication with iphone4s

Working frequency: 2.4GHz ISM band

Modulation method: GFSK(Gaussian Frequency Shift Keying)

Transmission power: -23dbm, -6dbm, 0dbm, 6dbm, can be modified by AT command.

Sensitivity: ≤-84dBm at 0.1% BER

Transmission rate: Asynchronous: 6K bytes ; Synchronous: 6k Bytes

Security feature: Authentication and encryption

Supporting service: Central & Peripheral UUID FFE0, FFE1

Power consumption: Auto sleep mode, stand by current 400uA~800uA, 8.5mA during transmission.

Power supply: 5V DC

Working temperature: –5 to +65 Centigrade

3.Equipment：

4.Hook-up diagram：

1. STATE: state test pins, connected to internal LED, generally keep it unconnected.

2. RXD: serial interface, receiving terminal.

3. TXD: serial interface, transmitting terminal.

4. GND: Ground.

5. VCC: positive pole of the power source.

6. EN/BRK: break connect, it means breaking the Bluetooth connection, generally, keep it unconnected.

Pay attention to the pin direction when inserting Bluetooth module, and don’t insert it before uploading test code

5.Test Code：

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_7_Bluetooth Remote Control

lesson_7.1_Bluetooth Remote Control

You could edit code step by step as follows:

  1. Click “Control”to get block

  2. Enter “Serial Port” to move block:

  3. Click “Variables” to drag out ，enter “Math” block to get block.

  4. Place it behind “value”，and change item into ble_val，click the drop-down triangle button to select char.

  1. Go to “Control” to get block，and click “Serial Port” to move out blockinto if block.

  1. Enter “Variables” to drag out blockinto do block，click “Serial Port” to move out block into block.

  1. Enter “Serial Port” to move block into do block，then click “Variables” to drag out into block.

Complete Program：

(There will be contradiction between serial communication of code and communication of Bluetooth when uploading code, therefore, don’t link with Bluetooth module before uploading code.)

After uploading code on development board, then insert Bluetooth module, wait for the command from cellphone.

6.Download APP

The code is the received signal by serial monitor, in this project, we send signal to control robot car via cellphone.

Then we need to download the APP.

iOS system

Enter APP STORE to search BLE Scanner 4.0, then download it.

Android system

Enter Google Play to find out BLE Scanner, then download.

(Enable“location”in settings of your cellphone; otherwise, app may not be searched.)

  1. After installation, open App and enable“Location and Bluetooth” permission.

  2. Open App, the name of Bluetooth module is HMSoft.

Then click “connect” to link with Bluetooth

After connecting to HMSoft, click it to get multiple options, such as device information, access permission, general and custom service. Choose “CUSTOM SERVICE”

Then pop up the following page.

Click（Read,Notify,WriteWithoutResponse)to enter the following page

Click Write Value to enter HEX or Text.

Open the serial monitor on Arduino，enter a 0 or other character on Text interface.

Then click “Write”, open serial monitor to view if there is a “0” signal

7.Extension Practice：

We could send a command via Bluetooth to turn on and off a LED. D3 is connected to a LED, as shown below:

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_7_ Bluetooth Remote Control

lesson_7.2_ Extension Practice

You could edit code step by step as follows:

  1. Click “Control” to get block

  2. Enter “Serial Port”to move block

  3. Click “Variables” to move blockintoblock，then go to “Math” to find out，

  4. Combine and change item into i:

  5. Click “Control” to get block，and enter “Serial port”to moveinto if block:

  6. Go to “Variables” to drag blockinto do block，enter “Serial port” to move outblock and edit code string as follows:

  7. Enter “Serial port” to drag out. Click “Text” to move outblock，and change “hello” into DATA RECEIVED:

  8. Click “Control” to move out blockinto do，click “Logic” to moveblock into if，

  9. Enter “Variables” to move into left box of “=”，then enter “Text” to get blockand leave it into right box“=”，change a into 1.

  1. Enter “Sensor”→“ControlOutput”→

  2. Drag it into the second do block，S end of red LED is connected to D3, therefore, set to Pin 3.

  3. Replicateonce and place it into the second do block. Change DATA RECEIVED：into led on.

  4. Copy code stringonce and change 1 into 0，click “HIGH” to select “LOW”，and change led on into led off.

Complete Program：

Click “Write” on APP, when you enter 1, LED will be on, when you input 0, LED will be off. (Remember to remove the Bluetooth module after finishing experiment; otherwise, burning code will be affected)

Project 8: Motor Driving and Speed Control

(1) Description

There are many ways to drive the motor. Our robot car uses the most commonly used L298P solution. L298P is an excellent high-power motor driver IC produced by STMicroelectronics. It can directly drive DC motors, two-phase and four-phase stepping motors. The driving current up to 2A, and output terminal of motor adopts eight high-speed Schottky diodes as protection.

We designed a shield based on the circuit of L298p.

The stacked design reduces the technical difficulty of using and driving the motor.

(2) Specification

Circuit Diagram for L298P Board

  1. Logic part input voltage: DC5V

  2. Driving part input voltage: DC 7-12V

  3. Logic part working current: <36mA

  4. Driving part working current: <2A

  5. Maximum power dissipation: 25W (T=75℃)

  6. Working temperature: -25℃～＋130℃

  7. Control signal input level: high level 2.3V<Vin<5V, low level-0.3V<Vin<1.5V

(3) Drive Robot to Move

The driver of motor driver shield is in parallel connection. You could control the direction of motors by altering the orientation of jumper caps(seen in the picture).

Through the above diagram, the direction pin of B motor is D4, and speed pin is D5; D2 is the direction pin of A motor, D6 is speed pin.

PWM decides 2 motors to rotate so as to drive robot car. The PWM value is in the range of 0-255, the larger the number, the faster the motor rotates

4WD Robot

Motor (A)

Motor (B)

Forward

Rotate clockwise

Backward

Rotate anticlockwise

Rotate to left

Rotate anticlockwise

Rotate clockwise

Rotate to right

Rotate clockwise

Rotate anticlockwise

Stop

Stop

Stop

(4) Equipment：

(5) Hook-up Diagram：

Attention: connect motors in compliance with the above connection diagram

(6) Test Code：

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_8_Motor Driving and Speed Control

lesson_8.1_Motor Driving and Speed Control

You could edit code step by step as follows:

  1. Click “Control” to get block.

  2. Go to ”Module”→”Drive_Module”→，

  3. Place it into block，

  4. The direction pin and speed control pin of B motor(left) are connected to D4 and D5. So set PIN 4 and PIN 5 as follows:

  1. Copyonce and place it into block，

  2. The direction pin and speed control pin of A motor (right) are connected to D2 and D9. So set PIN 2 and PIN 9 as follows:

  1. Duplicate code stringonce, set INA to HIGH and PWB to 200：

  1. Click “Control” to move out block，delay in 2000ms.

  1. Replicatefor four times，then set the code string as follows:

Complete Program：

(7) Test Result:

Hook up by connection diagram, upload code and power on, smart car goes forward and back for 2s, turns left and right for 2s, stops for 2s and alternately.

(8) Extension Practice：

Adjust the speed that PWM controls the motor, hook up in same way.

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_8_Motor Driving and Speed Control

lesson_8.2_Extension Practice

You could edit code step by step.

Complete Program：

Upload code successfully, the motors rotate slower.

Project 9: 8*16 LED Board

1. Description

If we add a 8*16 LED board to the robot, it will be amazing. Keyestudio’s 8*16 dot matrix can meet your requirements. You can create facial emoticons, patterns or other interesting displays yourself. 8*16 LED light board comes with 128 LEDs. The data of the microprocessor (arduino) communicates with the AiP1640 through the two-wire bus interface, so as to control the 128 LEDs on the module, which produce the patterns you need on dot matrix. To facilitate wiring, we also provide a HX-2.54 4Pin wiring.

2. Specification

Working voltage: DC 3.3-5V

Power loss: 400mW

Oscillation frequency: 450KHz

Drive current: 200mA

Working temperature: -40~80℃

Communication method: two-wire bus

3. Equipment：

8*16 Dot Matrix Display

Circuit Graph：

The principle of 8*16 dot matrix:

How to control each led light of 8*16 dot matrix? We know that a byte has 8 bits, each bit is 0 or 1. When a bit is 0, turn off LED and when a bit is 0, turn on LED. Thereby, one byte can control the LED in a row of dot matrix, so 16 bytes can control 16 columns of led lights, that is, 8*16 dot matrix.

Interface Description and Communication Protocol:

The data of the microprocessor (arduino) communicates with the AiP1640 through the two-wire bus interface.

The communication protocol diagram is shown below: (SCLK) is SCL, (DIN) is SDA:

①The starting condition for data input: SCL is high level and SDA changes from high to low.

②For data command setting, there are methods as shown in the figure below

In our sample program, select the way to add 1 to the address automatically, the binary value is 0100 0000 and the corresponding hexadecimal value is 0x40

image-20230614131926777

③For address command setting, the address can be selected as shown below.

The first 00H is selected in our sample program, and the binary number 1100 0000 corresponds to the hexadecimal 0xc0

image-20230614132000705

④The requirement for data input is that SCL is high level when inputting data, the signal on SDA must remain unchanged. Only when the clock signal on SCL is low level, the signal on SDA can be altered. The data input is low-order first, high-order is behind

⑤ The condition to end data transmission is that when SCL is low, SDA is low, and when SCL is high, the SDA level also becomes high.

⑥ Display control, set different pulse width, the pulse width can be selected as shown below

In the example, we choose pulse width 4/16, and the hexadecimal corresponds to 1000 1010 is 0x8A

image-20230614132040094

4. Introduction for Modulus Tool

The online version of dot matrix modulus tool:

http://dotmatrixtool.com/#

①Open links to enter the following page.

②The dot matrix is 8*16 in this project, so set the height to 8, width to 16, as shown below.

③ Generate hexadecimal data from the pattern

As shown below, press the left mouse button to select, the right button to cancel, draw the pattern you want, click Generate, and the hexadecimal data we need will be produced.

5. Connection Diagram

Wiring note: The GND, VCC, SDA, and SCL of the 8*16 LED panel are respectively connected to -(GND), + (VCC), A4 and A5 of the keyestudio sensor expansion board for two-wire serial communication. (Note: This pin is connected to arduino IIC, but this module is not IIC communication, it can be linked with any two pins.)

6. Test Code

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_8*16 LED Board

lesson_9.1_8*16 LED Board

You could edit code step by step as follows:

  1. Click “Control” to get block

  2. Enter“Module”→“Display_Module”→

  3. Leave it into block:

  4. Go to “Display_Module” to get blockand leave it into block，and click drop-down triangle button to set “clear”:

  5. Move out block，and set “”:

Complete Program：

image-20230614132123215

7. Test Result：

Wire according to connection diagram. The DIP switch is dialed to right end and power on, the smile face appears on dot matrix.

8. Extension Practice:

We use the modulo tool (http://dotmatrixtool.com/#)to make the dot matrix alternately display start, forward and stop patterns then clear the patterns. The time interval is 2000 milliseconds.

Get the graphical code to be displayed via modulus tool

Start：

Go front：

Go back：

Turn left：

Turn right：

Stop：

Clear:

Hook-up Diagram：

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_9_8×16 LED Board

lesson_9.2_Extension Practice

You could edit code step by step as follows:

  1. Click “Control” to get block

  2. Enter “Module” →”Display_Module” to move block:

  3. Then drag block.

  4. Click the drop-down triangle button behind “↑”to select “clear”.

  1. Copy again, click the drop-down triangle button behind “↑” to set “V”.

  1. Click “Control” to get block, delay in 2000ms.

  1. Replicate code stringfor three times，separately click the triangle button to set “↑”, “STOP” and “clear”.

Complete Program：

Upload code on development board, 8*16 dot matrix displays front and stop patterns, alternately.

Project 10: Line Tracking Robot

1. Description

The previous projects are inclusive of the knowledge of multiple sensors and modules. Next, we will work on a little challenging task.

We could make a line tracking car on top of the working principle of line tracking sensor.

Line tracking robot car:

image-20230920090514165

image-20230920090533162

2. Flow Chart

3. Connection Diagram

4. Test Code

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_10_Line Tracking Robot

lesson_10_Line Tracking Robot

  1. You could edit code step by step as follows:

  2. Go to“Control”Module to find out block.

  3. Click“Variables”to move out blockand duplicate it for two times.

  4. Separately change item into val_L, val_C and val_R.

  5. Go to“Math”to move out blockand copy it twice.

  6. Edit the following code string:

  7. Go to “Variables” to get block.

  8. Enter “robot”→“4wd-SmartCar”→:

  9. Replicatetwice，then change val_L into val_C and val_R；left_tracking into center_tracking and right_tracking:

  10. Click“Control”to get block ，and moveblock turns intoblock.

  11. Click“Logic”to move out blockand place it behind if block. Go to“Variables”to drag out blockinto left box of“=”block.

  12. Copyagain and leave it into right box of“=”b lock，and change 0 into 1:

  13. Enter“robot”→“4wd-SmartCar”→

  14. Place it into do block and set to 70:

  15. Go to“Control”to move blockinto else block，click，drag blockblock and move blockblock turns into block.

  16. Enter“Logic”Module to move blockinto if block，go to“Logic”to drag block into left box of “=”.

  17. Go to“Variables” to move blockinto left box of “=”block，

  18. Enter“Math”to drag blockinto right box of“=”block，then change 0 into 1；

  19. Replicate blockonce and keep it into right box of “and”block ，

  20. Change val_L into val_R, 1 into 0.

  21. Enter “robot”→”4wd-SmartCar”→

  22. Leave it into second do block, and change 0 into 200.

  1. Duplicate blockonce and keep it into else if block. Refer the following code string to edit:

  1. Click“robot”→“4wd-SmartCar”Module，→

  2. Place it into second do block，and change 0 into 200. Then drag blockinto second else block.

Complete Program：

5. Test Result

Upload code on the development board, plug in power and turn on the switch of smart car. The smart turtle car will walk along the black line.

Project 11: Ultrasonic Follow Robot

(1) Description

In this project, we detect the distance value of the obstacle to drive two motors so as to make robot car move and 8*8 dot matrix show smile face pattern.

The specific logic of ultrasonic follow robot car is as shown below:

Detection

Measured distance of front obstacles

distance（unit：cm）

Condition

Distance＜8

Status

Go back（set PWM to 100）

Condition

distance≥8 and distance＜13

Status

Stop

Condition

distance≥13 and distance＜35

Status

Go front（set PWM to 100）

Condition

distance≥35

Status

stop

(2) Flow Chart

(3) Connection Diagram

(4) Test Code

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_11_Ultrasonic Follow Robot

lesson_11_Ultrasonic Follow Robot

  1. You could edit code step by step as follows:

  2. Enter “Serial Port”to move block:

  3. Go to“Variables”to move blockinto block，enter“Math”to drag blockinto block，and change item into distance.

  4. Click“Variables”to move out block ，

  5. Enter “robot”→“4wd-SmartCar”→: .

  6. Click“Serial Port”to move out block，

  7. Enter“Variables”to drag outinto block.

  8. Click “robot”→“4wd-SmartCar”→

  9. Place it intoblock，and change 0 into 90.

  10. Click “Control” to move out blockappears, drag into blockfor 2 times and move into if block, then the blockis produced.

  11. Enter“Logic”to move block into if block

  12. Go to“Variables”to drag blockinto left box of “=”

  13. Click “Math”to move out block into right box of “=”, change 0 into 8, and “=”into“<”.

  1. Enter “robot”→”4wd-SmartCar”→

  2. Leave it into the first do block and set to 100:

  3. Go to“Logic”to move block into else if block.

  4. Replicateblock twice and place them into both side of “and” block.

  5. Edit the code string as follows:

  6. Click “robot”→“4wd-SmartCar”→，

  7. Leave it into the second do block:

  8. Copy block and once and place them behind the second“else if”block and else block.

  9. Click“4wd-SmartCar”to move out blockand leave it into the third do block and set to 100.

  10. Set code string as follows:

Complete Program：

(5) Test Result

Upload the code to the development board, plug in power and turn on the switch of smart car. Robot car will follow the obstacle to move(robot car only moves forward and backward).

Project 12: Ultrasonic Avoiding Robot

1 Description

We combine the hardware knowledge – LED matrix, motor drive, ultrasonic and servo, to build an ultrasonic avoiding robot!

In the circuit process, we can make use of ultrasonic sensor to detect the distance between robot and front obstacles. Control the motor rotating by measured data, thus control the robot motion and show the running state by dot matrix.

The ultrasonic avoiding capability is almost the same as the ultrasonic following function. We only need to change the source code.

The specific logic of ultrasonic avoiding smart car is as shown below:

image-20230920091155395

image-20230920091215892

2 Flow Chart

3 Wiring Diagram

4 Test Code

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_12_Ultrasonic Avoiding Robot

lesson_12_Ultrasonic Avoiding Robot

You could edit code step by step as follows:

  1. Go to “Control” to find out block.

  2. Click “Variables” to move out blockand duplicate it twice.

  3. Separately change item into distance, a1 and a2.

  4. Go to “Math” to move out blockand copy it for three times

  5. Edit the following code string:

  6. Enter “robot” → “4wd-SmartCar”→

  7. Leave it into block，change 0 into 90.

  8. Click“Control”to move blockinto block and delay in 300ms.

  1. Click“robot”→“4wd-SmartCar”→

  2. Keep them intoblock，click“↑”to select“clear”.

  1. Go to“Variables”to move out block，then enter“4wd-SmartCar”to get blockand combine it with block:

  2. Click“Control”to move out block, tap，and moveblock intoto produce bloc.

  3. Go to “Logic” to get and .

  4. Place into if block，and leave in the left box of block.

  5. Enter “Variables” to get block and keep it at left box of block “=”.

  6. Go to “Math” to move outinto right box of block “=”, change “=” into“>”. Replicate blockonce and set code string as follows:

  7. Click “robot”→”4wd-SmartCar”→.

  8. Leave them into block，and click“↑”to set“STOP”，then click“Control”to move out blockand delay in 100ms.

  9. Place it below:

  10. Go to “robot” → “4wd-SmartCar” →

  11. Place it into “do” block，change 0 into 180，

  12. Click“Control”to move out blockand delay in 500ms.

  13. Keep it into do block:

  14. Replicate code again and change distance into a1，then place it into do block

  15. Copy blockand delay in 100ms.

  1. Replicateonce and alter 180 into 0，a1 into a2.

  2. Finish the code as follows:

  3. Click “Control” and drag it into block and movethen we get block.

  4. Go to “Logic” to move out blockinto if block，then click“Variables”to drag blockinto left box of“=”block，and move blockinto right box of“=”，and change“=”into“＞”.

  5. Click “robot”→”4wd-SmartCar”→

  6. Place them into block，set to 200，click “↑” to select “←”.

  7. Change 0 into 90，and drag from “Control” into do block，delay in 300ms.

  8. Drag block,from“4wd-SmartCar”

  9. Place them into block，set to 200，click “↑” to choose “→”

  10. And set servo to 90 and move from“Control” and delay in 300ms.

  11. Finish the code as follows:

  12. Click “robot”→”4wd-SmartCar”→

  13. Place them into ，and set to 150.

5 Test Result

After uploading the code on the keyestudio V4.0 board, wire according to connection diagram. After the DIP switch is dialed to the right end, the smart car can automatically avoid obstacles.

Project 13: IR Remote Control Robot

1. Description

We combine the hardware knowledge – sensors, motor drive, and IR receiver, to build an infrared remote control robot car!

In the IR receiver section, we’ve listed out each key value of remote control. In this circuit design, we can set the key value in the code to navigate the robot car movement. The corresponding state pattern is displayed on the 8X16 LED matrix.

2. Flow Chart

The specific logic of infrared remote control robot car is shown below:

Initial setup

8X16 LED matrix Clear

Remote control

Key Value

Key state

FF629D

Go front（PWM set to 100）
8*8 LED matrix shows front icon

FFA857

Back（PWM set to 100）
8*8 LED matrix shows back icon

FF22DD

Rotate to left（PWM set to 200）
8X16 LED matrix shows leftward icon

FFC23D

Rotate to right（PWM set to 200）
8X16 LED matrix shows rightward icon

FF02FD

Stop
8X16 LED matrix shows “STOP”

Based on the circuit design, we can start building our own remote control robot.

3. Connection Diagram

4. Test Code：

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_13_IR Remote Control Robot

lesson_13_IR Remote Control Robot

You could edit code step by step as follows:

  1. Click “Control” to get block Enter “Serial Port” to move block:

  2. Click“robot”→”4wd-SmartCar”→

  3. Leave them into block，click “↑” to select“clear”:

  4. Copyonce and place it intoblock，and click“clear”to choose“V”.

  1. Enter “robot”→“4wd-SmartCar”→

  2. Click“Serial Port”to move blockblock，

  3. Click“Variables”to drag out blockinto block:

  4. Click “Control” to move out blockappears, drag into blockfor 5 times，the blockis produced.

  5. Enter“Variables”to drag blockinto“switch”block.

  6. Click“Math” to move blockinto the first case， change a into 0xFF629D；then go to ”robot”→“4wd-SmartCar”→

  7. Set to 200 and edit the code string as follows:

  8. Click “Math” to drag out blockinto the second case，and change a into 0xFFA857；

  9. Go to“4wd-SmartCar”to move out blockand

  10. Set to 200 and click “↑” to select “↓”

  11. Finish the code string as follows:

  12. Click “Math” to drag blockinto the third case， and change a into 0xFF22DD；enter “Robot”→”4wd-SmartCar”

  13. Place them into the third case, set to 200 and click “↑” to choose “←” :

  14. Click “Math” to move blockinto the fourth case，and change a into 0xFFC23D；

  15. Go to“robot”→“4wd-SmartCar”→

  16. Leave them into the fourth “case”，and set to 200. Click“↑”to select“→”.

  1. Go to “Math” to move blockinto the fifth “case”, and alter a into 0xFF02FD；

  2. Click“robot”→”4wd-SmartCar”→

  3. Keep them into the fifth “case”block，and click “↑” to set “STOP” .

Complete Program：

5. Test Result：

After uploading the code successfully on the keyestudio V4.0 board, wire according to the connection diagram, after DIP switch is dialed to the right end, we can use the infrared remote control to control the smart car movement. At the same time, the 8X16 LED light board displays the corresponding state pattern.

Project 14: Bluetooth Remote Control

1. Description

We’ve learned the basic knowledge of Bluetooth, in this lesson, we will make a Bluetooth remote smart car. In the experiment, we default the HM-10 Bluetooth module as a Slave and the cellphone as a Host.

Keyes BT car is an APP rolled out by keyestudio team. You could control the robot car by it readily.

2.Test APP

Special Note: Before uploading the test code, you need to remove the Bluetooth module. Otherwise the test code will fail to upload. After the code is uploaded successful, then reconnect the Bluetooth module.

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorialforMixly/MixlyCode/lesson_14_Bluetooth Remote Control

lesson_14.1_Bluetooth Reads Data

You could edit code step by step as follows:

(1) Go to“Control”Module to find out block

(2) Enter“Serial Port”to move block

(3) Enter “robot”→ “4wd-SmartCar”→

(4) Click“Serial Port” to find out blockand place it into block

(5) Click “Variables”to move out blockinto block

Complete Program：

Upload test code on V4.0 development board and insert the Bluetooth module. Then we need to download APP.

For iOS system

Note: Allow APP to access “location” in settings of your cellphone when connecting to Bluetooth module. Otherwise, Bluetooth may not be connected.

Search keyes BT car in App store

After installation, enter its interface.

Click “Connect”to search and pair Bluetooth. After connecting well, clickto enter the main page of 4WD smart car.

For Android System

Enter Google play store to search keyes 4wd

Its interface is shown below:

Click on APPimage-20230920092252404icon，searching the Bluetooth.

Click to connect the Bluetooth. HMSoft connected, Bluetooth LED will turn on normally.

After successful connection, press the button of the Bluetooth APP, and the corresponding characters are displayed in the serial monitor. For more details, as shown below.

Below is app of 4WD robot car interface and we have listed out what function of each key does

Key

Control character

Function

image-20230920092252404

match with connection HM-10 Bluetooth module

image-20230920094935297

disconnect Bluetooth

image-20230920095018541

Press: F Release: S

Press the button, robot car goes front; release to stop

image-20230920095035165

Press: L Release: S

Press the button, robot car turns left; release to stop

image-20230920095046556

Press: R Release: S

Press the button, robot car turns right; release to stop

image-20230920095059453

Press: B Release: S

Press the button, robot car goes back; release to stop

image-20230920095135966

Click to start the mobile gravity sensing; click again to exit

image-20230920095146783

Click to send “X” , then click “S”

Start line tracking function; click Stop to exit

image-20230920095202339

Click to send “Y” , then click “S”

Start ultrasonic avoiding function; click Stop to exit

image-20230920095221723

Click to send “U” , then click “S”

Start Ultrasonic follow function; click Stop to exit

3. Flow Chart

After designing the smart car according to the previous ideas, we need to start making smart cars according to the design ideas. We need to design the corresponding wiring, test code, and then wire the upload code to run, to ensure that the smart car can achieve the desired function.

4. Hook-up Diagram

5. Test Code

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_14_Bluetooth Remote Control

lesson_14.2_Bluetooth Control Smart Car

You could edit code step by step as follows:

  1. Click “Control” to find out block.

  2. Enter “Serial Port” to move block:

  3. Click“Robot”→“4wd-SmartCar”→

  4. Leave them into block，and click“↑”to choose“clear”.

  5. Copy blockonce and keep it into ，then click“clear”to select“V”.

  1. Replicate “robot”→ “4wd-SmartCar”→.

  2. Enter“Serial Port”to move blockinto block；

  3. Go to “Variables” to move out blockblock.

  4. Click “Control” to move out blockappears, drag into blockfor 5 times，the blockis produced

  5. Go to “Variables” to drag blockinto“switch”block.

  6. Click “Text” to move outand copy it for 4 times. Respectively set to F, B, L, R and S.

  7. Enter “4wd-SmartCar”to move out, and. Set to 200.

  8. Replicate block for four times and separately select “↑”, “↓”, “←”, “→”and STOP.

  9. Place the above blocks into “case” block and edit the whole code string as follows:

  1. Click“Text”to move into the fifth case block；

  2. Go to“robot”→“4wd-SmartCar”→

  3. Place them into the fifth case block，click“↑”to select“STOP”.

Complete Program：

6. Test Result

Upload the code on the keyestudio V4.0 board successfully. Stack the expansion board on the keyestudio V4.0 board and wire it according to the connection diagram. After power-on, the DIP switch will be dialed to the “ON” end. After connecting Bluetooth successfully, we can use the mobile APP to control the smart car to move.

Project 15: Multi-purpose Bluetooth Robot

1. Description

In previous projects, the robot car only performs single function, however, in this lesson, we integrate all of function to control smart car via Bluetooth control.

Here is a simple flow chart of multi-purpose robot car as for your reference.

2. Flow Chart

3 Hook-up Diagram

4. Test Code

The program will be generated if you find the following file and drag it into Mixly software.

File Type

Route

File Name

MIX File

../tutorial for Mixly/Mixly Code/lesson_15_Multi-purpose Bluetooth Robot

lesson_15_Multi-purpose Bluetooth Robot

Complete Program：

5. Test Result

Upload the code on the keyestudio V4.0 board. Stack the expansion board on it and wire them up according to the connection diagram. Plug in power and turn on switch on robot car. After connecting to Bluetooth successfully, we could control the smart car to move via App.

8. Resources

Wiki page: https://wiki.keyestudio.com/Main_Page

Official website: https://keyestudio.com/

Assembly Video Link: http://video.keyestudio.com/ks0470/