Design of single chip intelligent car

I bought a STM32 minimum system board some time ago and replaced my Shenzhou IV board.



That small board is a wireless module. It cost me a lot of money.














This one is modified from a helicopter remote control. There is also a wireless module inside, and the wireless module is a serial port transparent type. Because I am not very familiar with the SPI interface and SI4432. I am ashamed! [page]

The effect after this upgrade is very good. The car is very flexible. It can move freely in our dormitory.


Everyone who studies microcontrollers will make a car, and I don’t want to be an exception. This is the result of these weeks. 
The functions of the car include: infrared remote control function (dual remote control is available, steering function driven by servo, stepless speed regulation function, reversing function,
parking brake function, ultrasonic obstacle avoidance function, siren, and speed measurement function to be expanded.

This is the production site, which is quite messy.

The conditions are simple!




This is an ultrasonic obstacle avoider, which has not been debugged yet. The distance measurement is relatively accurate, but it is not easy to integrate it perfectly into the whole program. Use the first channel of TIM3 to capture the high level width of ultrasonic echo in input mode. The

main control board uses the Shenzhou IV experimental board. The one in the middle that looks like a triode is the infrared receiving head. I use the second channel of TIM3 to measure the infrared pulse width decoding in input capture mode.

One is on the TCL monitoring display, and the other is on the Tianmin TV box. TC L's infrared protocol is a bit confusing, but I have a USB analog oscilloscope, so it's easy to deal with after seeing the waveform. Tianmin uses the NEC infrared protocol, but not completely, the two address codes are not inversely related. I feel that buying a USB analog oscilloscope is very helpful to learn about the microcontroller. It is not expensive, mine is only more than 100.

Use the first channel of TIM2 to drive the servo with PWM wave, the servo is MG995. Use the second channel to drive the main motor with PWM wave. The entire rear wheel part was removed from an old toy car.

The power of the car comes from two lithium batteries, which were removed from my laptop. The computer is always plugged in, and I feel that the battery is useless without it, so it is better to remove it for experiments.



The relay is used for reversing. This relay is 6V Double-pole double-throw is still rare. I think I removed it from the circuit board of the emergency light. The transistor on the lower right is used to drive the main motor. The

one on the left side of the servo is a siren. It is driven by an 8050 transistor.

The main function used is the timer function of STM32. The timer function of 32 is really powerful. The timer function of 51 cannot compare with it. Its complexity made me dizzy for a long time, but now it is relatively clear.
It can be said that the car is a carrier and a mobile experimental platform. Various functions can be added to it in the future, such as manipulators. Now I use infrared remote control, which is only temporary. When the wireless module is used well, it will be changed to wireless. That is suitable for controlling the car. Yesterday, I found that the infrared remote control failed in strong sunlight during the test drive. Later, I thought about it and it was normal. The strong infrared rays in the sunlight are enough to interfere with the remote control. Also, the TV remote control can't keep up with the steering at all, because when you need to turn quickly, the control relationship is not a linear relationship at all. I think it should be suitable to use a stepless joystick. I have studied joysticks before, and I will buy a better one to control the car in the future.