Current and voltage meter-USB tester-V2.0 copy copy

For the porter, I changed it to OLED 0.96 i2c that can be purchased from tb, and changed the high voltage to low voltage. The protection voltage can be turned off when testing the battery, and the protection board is no longer needed.
The only flaw is that there is no mah maw time, and the software level is not good. There was no response after leaving a message to the original author.
 
 
 
 
 
 
 
The old version https://oshwhub.com/47415Y/hk32f030mf4p6-dian-liu-dian-ya-biao-shi-yan-dian-yuan-ban-lv-47415y
 
current and voltage meter, using battery Power supply, can set protection voltage and current.
The onboard OLED screen, buttons, and LED lights can also be used as a small development board.
Use INA226 to collect current and voltage. 0-36V, 0-5A. 0.9-inch OLED using I2C. It is powered by lithium battery and USB type-c charging is convenient to use and avoid interference.
It is mainly used as an auxiliary device for old-fashioned experimental power supplies (the kind that adjusts voltage with a potentiometer) and is used in series with the output line of the experimental power supply.
A new USB input has been added, which can be used as a USB power test meter.
 
Main functions:
1. Display voltage, current, and curve.
2. The protection voltage and current can be set. When the protection range is exceeded, the output will be turned off to protect the back-end circuit.
3. It replaces the "OUTPUT" button of the experimental power supply. There is no output every time it is turned on. After confirming the voltage, press the button to turn on the output. Prevent the experimental power supply from being misadjusted or the potentiometer being damaged.
In addition, the PCB panel and back cover are designed and connected using M2 copper pillars.
 
1) When starting up, the output is turned off by default and the last set protection parameters are loaded (EEPROM).
 
2) There are three pages 1, data display 2, curve display 3, parameter setting. Press and hold the SET key to switch.
 
3) In the data display & curve display interface, short press the ADD key to turn on the output, and short press the SUB key to turn off the output.
 
4) In the parameter setting interface, short press the SET key to switch the cursor, and short press the ADD key and SUB key to add or subtract parameters. Long press the ADD key and the SUB key to quickly add and subtract parameters.
Long press the SET key to exit the setting interface (save the parameters to EEPROM at the same time).
 
5) Parameter settings can set the protection
voltage 0-36V
current 0-5A
power 0-99W
curve voltage range 4.5V 9V 18V 18V 36V
curve current range 5A 2A 1A 0.5A
curve drawing time 1 time 2 times 5 times 10 times
 
6) Lower right corner Displays battery voltage and temperature.
 
2021.7.4 Hardware version V2.0 
 
re-boarded, removed 24c02, used internal FLASH EEPROM
hardware to add USB input and output ports, moved the sampling resistor behind the MOS, and there will be no no-load small current.
The PMOS driver adds an ICL7660 negative voltage driver, which solves the problem that low-voltage MOS cannot be turned on.
The LED IO is changed to
the IO sequence of the PD1 button.
If the setting parameters are incorrect, you can first run force_init_flash_eeprom(); and then comment them out.
The temperature display is added and the boot image display is removed (FLASH is not enough).