A digital power-quality meter: communication, sensing, calibration and the numbers on the screen.
Seeing 0x48 after a blank serial monitor felt much bigger than the address looked. The controller had asked a question and something on the board had answered. That excitement is part of the project account, and the later log gives the communication result a precise record: one device at 0x48 o
The scanner asks a wonderfully small question: does anything answer at this address? In the saved program, the loop tries addresses from 1 to 126, calls Wire.endTransmission and prints an address when the returned error is zero. It uses GPIO 8 for SDA, GPIO 9 for SCL and 115200 baud for the ser
My meter's voltage path has several different kinds of information along it. The ZMPT101B module produces a signal for an external ADS1115, and the controller receives converted values over I²C. I find the drawing more useful when I follow that route instead of only recognising the boxes. The A
GAIN_ONE is a small name with a large effect on the meaning of a reading. The saved raw sampler selects it and gives the scale as 0.125 millivolts per count. It then reads A0 and A1 separately and calls computeVolts for each. I can follow that much directly instead of leaving the ADC as a box l
RMS, power factor and I²C are the unfamiliar terms named in my report. They no longer look like one enormous subject when I put them beside the actual programs. The scanner deals with communication. The raw sampler selects GAIN_ONE and converts counts using a stated scale of 0.125 millivolts pe
The first number has quite a journey behind it. In the meter, the voltage module and current clamp produce signals for an ADS1115, and the controller receives digital readings over I²C. I like following that route because it makes the project more interesting than a screen full of values. My re
