#The7thLiChuangElectricityCompetition#USB power meter

 

* 1. Project function introduction:
USB power meter based on N32G430C8L7+INA199, with an accuracy of 1%. It can check the current when USB is working and supports 4V-24V version.
 
*2. Project attributes
refer to the official case of National Technology Training Camp. Laymen and non-professionals can try to replicate it.
 
* 3. Open source agreement
GPL 3.0
 
*4. Hardware part:
N32G430C8L7 is the main control, ADC samples INA199 output to calculate current, ADC samples the voltage between the voltage divider resistors to calculate the voltage value, and outputs it to the 0.91-inch OLED screen by I2C for display
 
 
*5. Software part:
Schematic diagram and PCB are drawn by lceda professional version full online version; code part is written by keil5, and the code refers to the official case routine.
 
*6. Competition LOGO verification
*7. Physical verification.
Reason for return: The following is not a physical picture.
*8. Problems encountered:
1. The power ground trace is only 10mil, so it needs to be widened and re-boarded;
2. The USB male and female shells are fixedly connected to the ground, and the connection with the ground needs to be disconnected, because some manufacturers like to use the shell for third-party protocols or use the shell for excessive current, so disconnect it to prevent affecting the test accuracy. Here you can see that I polished it directly;
3. The output voltage of the DCDC part is relatively low, and the problem needs to be checked;