This is now replaced by https://github.com/retromuz/esp32-bms-monitor - A web based battery monitoring system for SP15S020 BMS
Uses ESP8266 as brain. You can monitor with a browser either on mobile or desktop. Uses SVG.js for rendering cell icons. Ask for anymore features needed. Happy to implement.
Voltages are being shown below each cell. Capacity for each cell is currently based purely on voltage. When a cell is being balanced, the outline animates back and forth between black and purple. Currently configured for a 14S battery. As of now this is not easily configurable to support other cell configurations.
SP15S020 BMS has a UART serial port which works on 9600 baud rate. It provides 4 wires. 12V, TX, RX, GND. ESP8266 will open up a software based serial UART port when using this code on RX: GPIO4, TX:GPIO5.
Below are the connections:
BMS GND <> ESP8266 GND
BMS 12V <> ESP8266 VIN (nodemcu v3 has one)
BMS TX <> ESP8266 GPIO4 (software RX)
BMS RX <> ESP8266 GPIO5 (software TX)
LICENSE: MIT