Bantham, wireless energy meter
Posted: Sun Feb 09, 2020 10:20 am
The host micro is a PIC16F18877 with dual SPI bus. One bus is allocated to the polyphase energy monitor ATM90E32AS of Microchip, and the second to the LAMBDA62 LoRa (Semtech SX1262) transceiver module.
Split-core current transformers are used in the energy board for easy clamping on mains power cables.
The energy board can be used to either monitor a 3-phase mains power line or to monitor 3 single-phase power lines, coming from 2 different power sources like the mains and a domestic PV or wind generator and feeding the third line which is the consumer unit inside the home. With the appropriate program code, this system can balance the amount of power from the mains that will supplement the free of cost power provided by the green energy sources. In my case, it will be used as a companion of the EVSE that I have in development, to offer in the user the possibility of making an economy when charges an electric vehicle.
LCD indication description:
Upper line: Voltage
Second line: Amperage
Third line: Wattage
Lower line: 32-bit randomly generated number used for the pairing of LoRa transmitter - receiver.
The small difference in indications is owed to the Tx-Rx cycle of LoRa modules which is usually finished within 1 to 1.5 seconds (some times 2 sec).
The program code has been obtained with the use of Flow Code FC7 at whole, with a little help from Benj and medelec35 in two instances.
You can watch a clip with the two boards in action, as well as the pairing process.
https://www.youtube.com/watch?v=Z3ZHO5LrukQ&t=73s
The FC for the LoRa and for the ATM90E32 will be available in a few days.
Thanks