Android Smart Phone Bluetooth Remote Control Intelligent Smart Car 51 MCU (STC89C52 Code)

Introduction: Android Smart Phone Bluetooth Remote Control Intelligent Smart Car 51 MCU (STC89C52 Code)

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At the beginning of the new year, robot/Smart Car hobbyists and students (like all of you) about engineering, science and technology are busy with preparing for the robot competitions now.
It’s the great time to show the world your imagination and potential now.

ICStation R&D department has just finished this obstacle avoidance intelligent smart car which based on the STC89C52 MCU. It features with the function of obstacle avoidance,  infrared remote control and Bluetooth remote control system. It improves a lot on the usage of this intelligent smart car via the connects of various modules and controller.

BTW, this is just a sample which based on 51 MCU for your reference. You also can use other MCU to build your own gear. If you like 51, just leave us your email address to get the testing code.

- Main Parts Parameters
- Components
- Steps for installation Intelligent Smart Car
- Main Components Introduction

Parameters for your reference:
1. Motor parameter
- Power apply:6V-9V
- Reduction gear ratio:1:48

2. Dual L298 Driver Motor Module
- Driver chip: L298N dual H-bridge driver chip
- Drive section terminal supply area VMS: +5V ~ +16V. (The supply area should be +6V~+16V if the electricity should be taken in the plate.)
- Drive section peak current Io: 2A / Bridge
- Logical part of the terminal supply area Vss :+5V~+7V (the electricity can be taken in the plate +5V.)
- Logical part of the operating current range: 0 ~ 36mA
- Control signal input voltage range (IN1 IN2 IN3 IN4):
Low Level:-0.3V≤Vin≤1.5V
High level: 2.3V≤Vin≤Vss
Low Level:-0.3≤Vin≤1.5V (Control Invalid Signal)
High level: 2.3V≤Vin≤Vss (Control Valid Signal)

3. Ultrasonic module
Working Voltage : 2.4~5.5v
Static current: Less than 2mA
Detection distance range: 0~4.5m

1 x 4WD Smart Car Chassis $31.54
4 x Motor Reduction
1 x 7.2V Battery pack
1 x Speed Sensor $5.6
1 x L298N 4 Channels Step Motor Driver Module
40 x Dupont 20cm Color Cable
1 x SG90 Micro Servo Motor $3.04
1 x Bluetooth Transeiver RF Module
1 x US-100 Ultrasonic Sensor Module $5.46
1 x 4 Channel Tracing Module
1 x 51 MCU
4 x Infrared Sensor Obstacle Avoidance Module Probe
1 x Ultrasonic bracket
1 x Infrared Remote Control Module $2.8
1 x Steering Gear Bracket
6 x Copper Cylinder M3*45+6
1 x M3*7.5 screw

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Step 1: Installation of Smart Car Wheels

- Fix the motor and the base plate with 2pcs fixed plates and 2pcs screws (The side with the line ends of the motor should be faced inward.)
- Install the encoder and wheel

(no need to do this if you have the 4WD kits on hand)

Step 2: Install the Speed Measuring Module on the Baseboard

Speed Senor Module is for measuring the speed of intelligent smart car.

- It uses the correlation photoelectric slot type which can be triggered, as long as the transparent objects go through the groove. Output 5v TTL level.
- Use the schmitt trigger pulse jitter which is very stable and can be used for the smart car speed measurement, distance measurement and so on!
- Four pin definition: +5 GND OUT1 OUT2
OUT1, OUT2 are output level which can be connected to the microcontroller IO port directly. And each circuit will be with a LED indicating its output state.

Step 3: Install the 4pcs of Obstacle Avoidance Probes on the Baseboard

Step 4: Fix Six Pillar With 3.5cm on Either Side of the Baseboard

Step 5: Fix the 51MCU Module, 4 Channel Tracing Module, Dual L298 Drive Module on the Top Plate

1) 51 MCU
51 MCU is based on STC89C52 MCU. Our testing code is on the platform of STC89C52.
You also can use other MCU to build your own gear. If you like 51, just leave us your email address to get the testing code.

2) 4 Channel Tracing Module
It provides smart car, robot and other auto machines with solutions on the Multipurpose infrared detection system.
The probes are consisted of the discrete components, such as the infrared transmitting and receiving tube. And it uses the LM339 voltage comparator.

- Working voltage: DC 3.3V-5V
- Working current: above 1A
- Working temperature: -10℃—+50℃
- Mounting diameter: M3 screw
- Detection distance: 1mm - 60cm (The closer the distance, the more stable of the performance. White means it's on the farthest reflection point.)
- Dimension:
Mid Control board: 42mm(L)×38mm(W)×12mm(H)
Small forward board: 25mm (L)×12mm(W)×12mm(H)
- Output interface: 6 wire interface (1234 is 4 channel signal output terminal, + is VDD, - is GND)
- Output Signal: TTL Level (It can be connected to MCU I/0 directly. The Red indicator lights and outputs low level when inducts to the infrared light which reflected by the transducer. The indicator doesn't light and outputs high level when this is no infrared light.

3) L298N Driver Module

L298N driver module, using ST's L298N chip which can drive two 3-30V DC motor directly and provide a 5V output interface. What's more it can supply 5V MCU with power and support 3.3V MCU ARM control. It can easily control the DC motor speed and direction and the 2-phase / 5 line 4 phase stepper motors.

Step 6: Install the SG90 on the Top Plate and Fix the Top Plate and Baseboard

TowerPro SG90 9G Micro Servo Motor RC Robot Helicopter Control

Dimension: 22mm x 11.5mm x 22.5mm
Net Weight: 9 grams
Operating speed: 0.12second/ 60degree ( 4.8V no load)
Stall Torque (4.8V): 17.5oz /in (1kg/cm)
Temperature range: -30 to +60
Dead band width: 7usec
Operating voltage: 3.0V~7.2V
Fit for ALL kind of R/C Toys

Step 7: Install the US-100 Ultrasonic Sensor Module on the SG90

The measuring distance of US-100 Ultrasonic Sensor Module can be up to 0~4.5m. And the input voltage range is 2.4~5.5V, while the static current is less than 2 mA.  Built-in temperature sensor can correct the distance measurement results. With more communication formats.

Main Technical Parameters
- Working voltage: DC 2.4V~5.5V
- Static current: less than 2 mA
- Working temperature: -20~+70℃
- Output: Level or UART
- Detection angle: <15°
- Detection range: 2cm-450cm  (Detection precision:0.3cm+1%)

Pin 1:VCC
Pin 2:Trig 
Pin 3:Echo 
Pin 4:GND
Pin 5:GND

Step 8: Wire Connection

Arrows - the ends of the signal line

Download the wire connection table which based on the STC89C52 MCU here:

Step 9: Thank You for Your Visiting!

Please feel free to contact us if you have any unclear or need any parts or material from us.


Best regards,
ICStation Team

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    4 Discussions


    3 years ago

    Hello can you cant me the code for 51 mcu


    4 years ago on Introduction

    Hello can you sent the 51 mcu code please and thanks ... darkhours2 @

    andrea biffi
    andrea biffi

    6 years ago on Introduction

    That's great but it would be nice to have a little description in some steps which have now no text, and maybe a diagram of connections, since table is not so intuitive at a first glance...


    Reply 6 years ago on Introduction

    Hi Andrea, thank you for your comments! We'll pay more attention to it later.