An STM32 development board with a screen, no pin header, and good looks

This is a development board whose main control is STM32F103C8T6. It is originally designed to be used as a development board and embedded in practical projects. It can greatly improve beginners’ learning motivation. For example, making a simple clock can be placed on the desktop when powered on. Although the idea is good, there are many design aspects that have not been taken into account. It is now a version with many bugs. Strong and interested experts can help to correct the bugs. Those who want to learn how to use it can also take it directly. Use it, I will list the BUG in detail later.

First, let’s introduce the onboard peripherals of this development board . The STM32 internal peripherals will not be listed.

1. 2.8-inch, SPI serial screen, purchased from Zhongjingyuan Electronics.

2. 4-way LED lights.

3. 4-way touch buttons.

4. A small size passive buzzer.

5. Onboard CH340 serial port communication, the program cannot be downloaded.

6. SWD download interface.

7. AT24C02, IIC controlled EEPROM.

8. W25Q128, SPI controlled FLASH.

9. DS18B20 digital temperature sensor.

This development board has the following features :

1. Different from traditional development boards with pin headers, this development board uses header pins as IO ports, which is neat and beautiful. However, some friends have pointed out that it is also a problem that the header pins will become loose after being used many times.

2. Use the DIP switch to switch the boot, so you no longer have to dig at the jumper cap with your fingernails!

3. The development board screen is not removable and is protected by an acrylic board, making it look great!

But I just mentioned that the development board has many bugs . I will list the ones I have discovered for your reference:

1. EEPROM cannot be used.

2. The screen resolution is relatively high, and the memory of the main control chip is small. It has a "little horse pulling a big cart" feeling, and it cannot even store a full-resolution picture. I give two solutions: ① External or modified Add an SD card slot to the PCB ② Use a higher memory main control chip. The alternative chip is a domestic AT32 chip or a higher-level stm32 chip, but the PCB needs to be redrawn. I have not verified the feasibility of the above two methods.

3. The SPI flash is not verified because the chip is lost and lazy, and has not been repurchased.

4. There are fixed corners at the four corners of the screen but there are no holes in the PCB. It requires multiple layers of double-sided tape to fix it, or you can use an acrylic cover directly.

5. The long row of motherboards is a little crowded when installed and can only be used with reluctance. A capable partner can redraw the PCB to lengthen the spacing.

6. The 32768Hz crystal oscillator does not vibrate.

All other functions are working normally.

The headers use patch headers, which can be found by searching on Taobao. 99% of the entire motherboard uses SMD components, which is neat and beautiful. I have obsessive-compulsive disorder and basically use the idea of ​​symmetry and centering in PCB layout. PCB wiring capabilities are limited and can only be routed.

The whole board adopts a sandwich structure of base plate + motherboard + acrylic cover. The base plate mainly provides pin information and some logos. The acrylic cover is used to protect the screen. There are M3 screw holes distributed in the four corners. M3*16 screws and M3*4 copper are used. The columns are fixed in series, and the base plate is fixed with M3 nuts. For details, please see the video:

Demo video address:

https://www.bilibili.com/video/BV1wY4y147wJ?spm_id_from=333.999.0.0&vd_source=b712a3bad59f0608d305695f96fd9910