SC909 three-phase multi-function meter

The three-phase multi-function meter based on RN8302 and ATmega3208-AU can normally collect three-phase voltage and three-phase current, and has the function of energy measurement. Additional 485,4-20ma industrial communication capabilities. There are 5 groups of custom input points and 4 groups of output points.

Use ATmega3208-AU microcontroller and metering chip RN8302 to realize multi-function meter design. Among them, RN8302 has good stability, and ATmega3208-AU has sufficient stability when the computing power is sufficient, and can be used in industrial electromagnetic environments. The overall performance is very competitive and has the ability to be expanded later. V3 version update: 0) Update date 2021-04-03; 1) Delete V1 V2 version. 2) Modify the model to an industrial product model; 3) Adjust the working voltage to 5V to increase product stability;

V2 version update record: 0) Update date 2021-03-20; 1) Since there are not so many pins, QFN32 compatibility has been added; 2) Some capacitor specifications have been modified to facilitate ordering; 3) SWD wiring has been modified, adding GND; and add the silk screen mark to SWIO SWCLK.

UP: 2021-03-26. The power board was soldered and actually tested to output 13.6V/5.2V. After some effort, I came to the conclusion that the VCC capacitor must be exactly 1uF. After replacing the capacitor, the no-load output is 12.52V. Full load 350ma, voltage 11.96V.