Background of the project

At present, the Raspberry Pi has been configured with the HomeAssistant. It is expected to be connected to the relevant Zigbee equipment. I bought some at the seafood market. If I want to connect to the Ha, I need a Zigbee gateway. I read the sharing of some experts online and used the module to make my own gateway. After a few days of exploration, , board verification, and after several optimizations, the plan has basically been determined.

The design needs to
be seamlessly connected to the Raspberry Pi (the device it is installed on) for easy fixation and the use of related interfaces.
It is equipped with a fan to dissipate heat for the Raspberry Pi. The daily temperature of the Raspberry Pi 3b in my hand is 50 to 60 degrees, which is not even 7 In the hot weather in August,
the Raspberry Pi temperature control fan switch can be
integrated with an ambient light sensor. Since our company is making this sensor, we are familiar with sensor debugging
with status indicators that display different states and warnings
. . . . . . .
The solution is to select
the zigbee gateway CC2652P/E72-2G4M20S1E. For online DIY examples, please refer to
the ESP32 WROVER module. I happen to have this module on hand and can access the ha
debugging process
drawing board through esphome. After three optimizations, I am a novice because I am not familiar with zigbee. ,

When I came back from the first version, I found out how to communicate with the Raspberry Pi? All the experts have a way to convert ch340usb to serial port. It should be impossible to use it without a serial port module. . . . The optimized version was changed, and a serial port and type c were added. As you can see from the picture above, it is not the case. The Raspberry Pi has a serial port and can communicate directly through the serial port, so the third version was changed. It is also the final version, but it is not there yet. After verifying
the first version, I found that the fan on hand could not match the opening, so I manually used an electric drill to open the hole to the appropriate position, which was more time-consuming. The second version was optimized. As shown in the first picture, it can match fans of different sizes. The 12v fan that I used to pick up garbage is powered by 5v. It is really quiet and basically no sound can be heard. This is a surprising thing and an unexpected gain.
When I was burning the esp32 after the first version, I found that it kept restarting, and all kinds of tossing, almost doubting my life. Later, Baidu verified it and confirmed that it was a power supply problem. I added two more 100uf capacitors and it was very stable, so the ESP module is very important for power supply. Very particular, when there are unexplained problems, it is always a good idea to check the power supply first.
After returning from the first version, I found that the esphome customer controlled the colored lights and happened to have ws2182 on hand. In the third version, this light was added to serve as a status indicator light. In
the third version, some pins of the esp32 were led out for subsequent expansion. Including adding the basics of the 0.96-inch OLED
third version to the second version, and re-adding the interface to connect with the Raspberry Pi, which can save the type C power supply and serial port module, and the E72 communicates directly with the Raspberry Pi.