#The7thLiChuangElectricityContest#USB voltage and current meter

* 1. Project function introduction:
USB voltage and current power meter based on N32G430C8L7, with direct data line connection, can support 12V/3A fast charging (limit power not tested).
 
* 2. The project attributes
are made public for the first time, and fine-tuned on the basis of the official project.
 
* 3. Open source agreement
GPL3.0
 
* 4. The hardware part
adds an RGB color light for charging status display based on the official schematic diagram of the training camp, and adds a crystal oscillator circuit and some lead-out ports to facilitate subsequent debugging and redevelopment (see the schematic attachment for details).
Since the dcdc power supply circuit fails to stably output 3.3V when 5V is input, personal ability is not enough to correct the parameters, so the AMS1117 linear voltage regulator circuit is used instead of the official BL9342 power supply circuit.
The debugging interfaces such as the download port and serial port are changed to the patch pad to further save PCB space.
 
* 5. The software part
uses the program provided by the LiChuang training camp and modifies it on this basis.

Use timer 6, enter the timer interrupt at a frequency of 100us, and perform status judgment and control RGB in the interrupt. RGB status display:
Power
RGB status : Green light is always on
below 0.25W , normal mode is 0.25W-10W , blue light is always on, high current mode is 10W-40W , blue breathing light is over 40W , overload mode is red, breathing light =========!!! Be careful not to work in overload state for a long time, exceeding rated power for a long time may cause damage to the meter!!! ========= Added bit-band operation control GPIO, but only supports GPIOA and GPIOB. *6. See the attachment for BOM list. (For reference only) *7. Competition LOGO verification * 8. See the attachment for project demonstration video. (Because the breathing light effect is not specially debugged for the camera, the breathing effect in the video is not ideal, and the breathing light seen by the human eye is smoother and more comfortable)