#The7thLiChuangElectricityContest#USB voltage and current meter

* 1. Introduction to project functions
The project is mainly a reproduction of the functions in the summer training camp example, and the functions have not been changed much! The relevant valuable components have been replaced according to the components I currently have.
The USB ammeter made based on N32G430C8L7+INA199 has an accuracy of 1%, and can check the current when the USB is working.
 
* 2. Open source agreement
GPL 3.0
*3. The main
control of the hardware part uses the national technology N32G430C8L7. You need to know the pin sequence when welding.
The reset circuit is officially implemented with a pin header. I designed it as a button here for easier reset.
 
BOOT circuit This is very important. I didn’t connect it at the beginning to connect here, which resulted in the search for the chip MCU
 
crystal oscillator circuit.
If you consider that the circuit may be upgraded later, you can add an 8mhz external crystal oscillator circuit
INA199A1 gain: 50V/V voltage output, current shunt monitor (also known as current sensing amplifier) ​​is often used for overcurrent protection, precision current measurement or closed-loop feedback circuit for system optimization. This series of devices can sense the voltage drop across the shunt resistor at a common-mode voltage of –0.3V to 26V that is independent of the power supply voltage.
 
ADC analog-to-digital conversion, since the pin of Guoming Technology has this function, if you want to collect voltage
 
 
, you need to add an analog-to-digital conversion IC and then a voltage regulator circuit. Since the operating voltage of the MCU is 3.3V, this circuit is needed to achieve the external voltage step-down and voltage regulation to 3.3V.
 
Then there are 2 pin headers. The first picture is the serial port and SW debug interface.
The second is the peripheral OLED screen interface.
 
 
*4. Software part
Compiler: ARM Compiler version 5
Debugger: ST-Link V2
can use the official serial port to download software
 
*5. Competition LOGO verification and physical pictures
 
 
*6. Demonstrate your project and record it as a video and upload it