Wowo Liangshanpai smart car

# **Introduction:**

This is a smart car based on the Liangshan School development board. Its schematic diagram refers to the official design of Lichuang. Draw by using Lichuang EDA Professional Edition.
It uses an enhanced high-tech human presence sensing module to realize a fishing car that can sit still for a long time and only move when there is no one around.
![wocar.jpg] ![image.png] The human body sensing module can obtain and modify the fishing threshold through the serial ports PA9 and PA10 (the code has not been implemented yet, and Bluetooth configuration is currently used). Whether to enter the fishing state, the human body sensing module outputs high and low levels to the PA11 pin. When there is someone, it outputs high level to stop fishing and start moving; when there is no one, it outputs low level and enters the fishing state.

# **Function introduction: **
This is a smart car based on the Liangshan School development board. It uses the Lichuang EDA Professional Edition to draw the schematic diagram. This smart car uses an enhanced high-tech human presence sensing module to realize that it can sit still for a long time and fish when no one is around. The fishing car that only needs people to operate is called the Wowo smart car because it stays motionless for a long time.

The human presence sensing module can obtain and modify the fishing threshold through the serial ports PA9 and PA10. However, since the code has not yet been implemented, it can only be configured through Bluetooth. When the human body presence sensing module detects someone, it will output a high level to the PA11 pin, causing the car to stop fishing and start moving; when it detects no one, it will output a low level, making the car enter the fishing state. .

In summary, this is the use of high-tech human presence sensing modules to realize the fishing function of Wowo smart cars. The car can judge whether it has entered the fishing state based on the output high and low levels of the human body presence sensing module, thereby realizing the function of moving when there are people and fishing when no one is around.

# ** Schematic diagram description: **
The schematic diagram of this Wowo smart car refers to the official design of Lichuang. Based on the official schematic diagram, the remote control function is removed and replaced with a human body presence sensing module interface. Since it is a fishing car , I definitely can’t work for a long time. The reserved Bluetooth module, ultrasonic module, and photosensitive part all need to be used experimentally. Unfortunately, time is limited and not all tests have been completed.

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# pcb design description:
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The official PCB design exceeds 10*10cm. In order to reduce it to 10cm, we re-layout the wiring and give up the beautiful appearance. It is a square lump. I originally wanted to try other shapes of cars. , such as a circle, but time was tight and I couldn’t finish it, so I had to give up.


# **Key program description: **
It was said before that "the Bluetooth module, ultrasonic module, and photosensitive part all need to be used experimentally." In fact, the Bluetooth module is also used for fishing. As we all know, the Bluetooth of mobile phones is generally turned on. If it is close to the car, it means that someone is coming. This way, you can stop fishing in advance to prevent being discovered, and avoid the problem that the sensing range of the human body sensor module is reduced behind the partition wall.
The ultrasonic module is also designed to catch fish. In the non-fishing state, after the ultrasonic wave senses an obstacle, the car should move a few more times to express itself and avoid being said to be fishing...
The photoresistor part is actually also for fishing, God. Who can work when it's dark? Therefore, the weight of light sensitivity is greater than that of the human body. Therefore, when the light is too dark, even if someone is hiding in the car, the car will not move and the light will turn on a few times at most. (ー_ー)!!


# **Action logic:**

![image.png]

# **Important material purchase:**

The car motor driver chip initially selected rz7899 C92373, but the chip has been out of stock. A classmate reminded me that I used BDR6126D, which happens to have a coupon, and the pin functions are the same, but the performance is a little worse, and it is a plug-in. I modified the package and used it. Is it a good idea? It can be used.

N20 motors are all equipped with reduction gears and wheels. I refer to everyone’s selection plan. Generally speaking, the one with high speed has small torque and the car can carry less things. The one with low speed has high torque and can carry more things. This is a small car for fishing, but it has to perform well when there are people around, so a high-speed solution is used, but the torque is much lower, and only two 18650s are used for the battery. As long as you can catch fish^_^


# **Assembly instructions: **

The problem discovered during assembly is that there is a problem with the position of the drive motor chip. Of course, this is because I did not use my brain after referring to other people's plans. Plug-in chips have this problem, SMD It's good if it's a type, it won't affect the chip due to the motor, so as to avoid short circuit.


# **Summary:**
By calling various peripherals and detecting the environment, the Wowo Fishing Car can successfully realize the function of fishing when people are not fishing, and fishing when people leave. The prerequisite is that it is dawn ; Successfully achieved the goal of rather staying still than moving; overall, it is really a model car that has successfully fished.