Power monitoring

Description input (POWER_IN): 12-16v DC power output (POWER_OUT): equal to the input current voltage, the maximum designed output current is 6.5A. Using ina266 as the current and voltage acquisition chip, the maximum offset voltage is 10 microvolts, and the error is 0.1%.
The onboard design is based on IP6505 fast charging circuit. The USB interface output supports fast charging up to 24W, and supports QC2.0, QC3.0, and PE1.1 , PE2.0, AFC, AFCP, BC1.2 fast charging protocol, you can charge mobile phones/power banks or other digital devices through this USB interface, and record the charging capacity at the same time. POWER_OUT is a DC power output interface that can be connected to routers and other equipment for measurement The real-time power consumption and electric energy used can be viewed on the mobile phone through the "Bluetooth Serial Port" software by connecting to Bluetooth, such as real-time current, voltage, capacity and other information.
 
Independent parameter setting matters If the current reading is found to be inaccurate, it is due to the error in the INA226 sampling resistor. You need to reset the current conversion parameters to correct it, which is to set the CAL_REG register of ina226.
CAL is the CAL_REG register, R is the resistance of the sampling resistor, Maximum Expected Current is the designed maximum current, and the calculation method of the CAL register is as shown in the formula below.
 
CAL register setting method
This board is designed with two INA226 chips, which respectively measure the output current and voltage of the USB interface and the output current and voltage of POWER_OUT. The two measurement circuits work independently. Set the CAL register of the INA226 that measures the POWER_OUT output in the program INA226.c INA226_Init() function setting of the file, set the CAL register of INA226 for measuring USB output in the QC_INA226_Init() function setting of the program QC-INA226.c file. As shown in the figure below:
 
operate the K1 button: long press to turn off USB fast charging output, short press to turn on USB output. K2 button: Short press to switch the OLED display to display the current, voltage, power and energy consumption parameters of USB output and POWER_OUT output. K3 button: Short press to switch whether the work indicator light is on and flashing, long press to clear the energy consumption information recorded by USB output. K4 button: Short press to clear the energy consumption information output by POWER_OUT.