First of all, you have to have basic knowledge, electricity counting, analog electricity (electricity counting is more important than analog electricity) and C language. If you are doing an upright car, you have to know some automatic control principles.
Then, you have to understand several modules, one by one in the order I said, and you will get it slowly.
First: power supply circuit. You have to understand this part first. After all, the power supply is the foundation of the circuit. The circuits used in Freescale smart cars are generally 5V and 3.3V, so you should master these two linear voltage stabilizing chips and ignore 12V. The recommended power chips are: 7805, 7905, 10 15,117-3.3, TPS series of TI company. This series has the highest accuracy, but I don't think you can use it because it is too expensive, and the accuracy of these chips exceeds the actual requirements of cars.
All you have to do is find a chip you want and solder a circuit on the general board according to the peripheral circuit solution in the data sheet. If the voltage at the output of the chip is 5V or 3.3V, OK, congratulations, you can enter the next stage (the power supply part does not suggest that you buy ready-made products online, for one thing, the price is too low, and for another, it is really unnecessary).
Second: the driving circuit, usually an H-bridge. First of all, you should understand the basic principle of H-bridge. It's all over the internet. I used to use the chip BTS7960, but if you are a beginner, you can build a simple one, such as 3205 and 4905. You can buy this in the electronic market or online.
Third: speed measuring module. Encoders can be used and can only be bought online. In fact, according to my experience, you'd better buy Omron's encoder, which has high precision and good quality. The output line of speed measurement is directly connected to the pulse counting port of single chip microcomputer, and then the number of pulses per unit time is recorded by software, so you can measure speed!
Fourth: tracking sensor. It depends on which group you belong to. I have participated in the photoelectric group twice, so I know a lot about photoelectric sensors. It is estimated that I will continue to use linear CCD this year. You can enter Lanzhou Electronics on Taobao, which is sold in all stores.
Fifth: others. If you have the spare capacity to learn, I suggest you look at how to do the display and how to add buttons. When you go to the competition in the future, you can't use the computer to download the program again on the spot. You have to remember this, so you can only operate the parameters of the single chip microcomputer program through the keys and display screen you welded.
Finally, an experienced person will give you a warning. I will learn it step by step. You will certainly encounter many difficulties in the future, but remember not to be impatient. Some things are urgent.
I wish you success, ha, and enter the national competition!