#The 7th Lichuang Electronic Competition# Mobile wearable device solution evaluation board

# It's very painful. All sensors in the epidemic area have not been shipped.

1. **Since the sensors have not been shipped, I can only put the time on the screen. Originally, N32 detected the sensor data and communicated with the 8266 serial port. Now the result is that only the serial port transmission and reception are verified. The sensor will be tried again when it arrives. **
2. **There is no problem with the hardware verification of 8266 and N32. The power chip cannot be started. There is no problem with the circuit program. The IIC output is also normal. I am going to change the chip and try again (fake chip???)**
3. **Memorial knife head hand welding QFN package. 。 。 。 **

### * 1. Project function introduction

The main purpose of this project is actually for a wearable project that I have been conceiving, a networked wearable device (similar to a watch) of 32 series chips and 8266. However, I am not very familiar with programming some very expensive (more than 20) high-precision small package sensors and I am not very confident about PCB wiring. So, with the dual support of the 7th LiChuang Electric Competition and LiChuang EDA Summer Training Camp, I decided to use modular stacking to make a wearable device verification board based on N32+esp8266.

### *2. Project attributes

This project is open to the public for the first time. It is my original project and has not participated in any competitions or awards!

### * 3. Open source agreement

This project follows the GPL3.0 open source agreement!

### *4. Hardware part

This hardware part is modularly drawn. If you need to use it, you need to use DuPont wire to connect it. Because you don’t need to scrap the entire board because of a wrong drawing at one end, it greatly saves free resources and allows more people to verify their own works.
In order to facilitate the modular drawing of PCB, I also divided the schematic into blocks relative to the function, mainly divided into five parts.
First of all, there are two main control chips. ESP8266EX is drawn separately, and N32G430C8L7 is drawn separately. In order to run stably, I think the two MCUs are powered by two LDOs respectively. Since 4-layer boards will be drawn in the future to compress the size of the circuit board, in order to solve
the problem that the multi-channel LDO power supply is too large and also needs to take into account battery charging, power detection, long-press on and off, power overcharge and overdischarge, high temperature and power protection, etc., which require large-area components and layout, the power management chip is introduced. In order to fully support the domestic "U", the powerful APX173 power management chip is selected. It not only uses a small QFN package, but also perfectly solves all the functions I mentioned earlier (although the power ripple is average when multiple power supplies are supplied, it can't stand too many functions). Below I will directly attach a picture of the characteristics in the datasheet to feel its power.
![image.png]
#### The other miscellaneous sensors are nothing else. 0402 welding is too eye-consuming. . . The power chip is not yet done, so I am not in the mood to write a brief introduction. I will come back to continue working on the document after I finish the verification...

### *5. Software part

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I mainly wrote the UI, and will open source it after sorting it out. The transparent oled is really beautiful.

### *6. BOM list

## Lichuang sponsored 100, and I paid more than 100 myself. Thank you Lichuang for your support!!!

###### please refer to the attachment:

![image.png]
### *7. Contest LOGO verification

![image.png]
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### * 8. Demonstrate your project and record it into a video and upload it to

station b. Video link: [[LiChuang Summer Training Camp] Wearable Device Evaluation Board-Bilibili] https://b23.tv/RiHoEJL
Picture:
![C4C2D4B55F9959E38508D0B91F2E5AB7.jpg] ![659A2DD5068DA8D10D4C972B899697FC.jpg] ![8510F5AE8DCDD4EECA5EFDF29E80B923.jpg]