#The7thLiChuangElectricityContest#USB Ammeter

* 1. Project function introduction:
USB ammeter based on N32G430C8L7+INA199, with 1% accuracy and serial port SPI 0.96-inch TFT color screen display, which is very small and beautiful. It can check the current when USB is working and display the core temperature of the chip at the same time.
 
 
*2. Project attributes:
The whole project has gone through 3 versions.
 
The first version is just for practice. In this version, the FPC socket is designed on the back, and the slot is opened on the front of the PCB. The FPC line passes through the slot and is inserted into the FPC socket on the back, but problems also arise. The screen I bought is a plug-in type with a 0.5mm pitch. The exposed weldable part of the FPC socket pin is only about 0.5mm, less than 1mm, which is much more difficult to weld than the chip. For a novice like me, it is really difficult to control. I spent 3 or 4 FPC sockets and couldn't get it done. Fortunately, the I2C interface was introduced, so this version just ran the training camp case.
 
 
Since I had bought dozens of N32G430s before, and spent a lot of money on components, and even spent a long time drawing the 3D shell, I didn't want to waste it, so I started the second version, and also bought a Deer Fairy Teppanyaki and solder paste. The reset and BOOT buttons and slots of the first version really took up too much space, so the buttons were removed in the second version and replaced with test points. At the same time, in order to match the teppanyaki, the FPC socket was also moved to the front. After the modification, I went to make the board, thinking that there must be no problem this time. While waiting for the board, I wrote the serial port SPI program and transplanted the ST7735S driver to N32G430.
 
 
I have to say that Teppanyaki is simply a magical tool. After the second version of the PCB was obtained, the FPC socket was welded smoothly, so I started to debug the serial SPI color screen. I made a low-level mistake here. The FPC socket of the first version was on the back. I didn’t pay attention to the order of the FPC wiring in the second version. I couldn’t debug it no matter what I did. During the period, the screen smoked twice and it was hot to touch. I thought I bought a bad screen and almost gave up. Later, I carefully compared the schematic diagram and PCB and found that I had plugged the wiring in reverse. After finding the problem, it was easy to solve. Fortunately, the screen was not burned out, but there was a small piece of the screen backlight that did not display, and it could still be used.
 
 
 
The third version is based on the second version, adjusting the direction of the FPC socket, saving space, adding a 1x4P pin header interface (3V3, PB8, PB9, GND), and also leading out the PA6 and PA7 pins as test points, which can be connected to a buzzer or something.
 
 
 
* 3. Open source agreement
GPL3.0
 
*4. Hardware part
MCU main control part, voltage and current sampling, 5V to 3.3V, TFT screen FPC interface, indicator light, SWD download interface, UART interface, I2C interface and other circuits.
 
 
*5. Software part
 
* Compiler: ARM Compiler version 5 (-O0)* MDK version: 5.36* Debugger: ST-Link V2
 
 
 
*6. BOM list,
 
please see the BOM list below
 
*7. Competition LOGO verification
 
 
* 8. Demonstrate your project and record it as a video and upload it