Solar Energy Manager for ESP32 (SEM.32)

SEM.32 (Solar Energy Manager 32) based on ESP32 controller, Soyosource Inverter, Huawei r4850g2 power supply, JK-BMS and 48V battery. It helps You to maximize the usage of self generated solar power.

Main features:

• [x] control of inverter to minimize power usage out of the grid (over RS485)
• [x] control of charger to maximize own usage of solar power (over CAN-bus)
• [x] adjustable power thresholds
• [x] optional manual control of charging power
• [x] optional dynamic load calculation to reduce wear of battery due to low chage status
• [ ] charge current limitation
• [x] access to JK-BMS data (over RS485)
• [ ] new web GUI
• [x] wifi configuration portal
• [x] MQTT client
• [x] scalable code for new features
• [x] CAN dbc file for the charger
• [x] runs ESP32 boards with RS485+CAN shield
• [x] runs on ESP32 and on the BSC-Hardware

Web GUI

Hardware components:

• Inverter:

  • Type: GNT 1200LIM 48
  • MAX: Const. Power: 800W (1200W solar operation)

• Charger:

  • Type: Huawei R4850G2

• BMS:

  • Type: JK-BD6A20S8P
  • Software V.: V10.XY

• Battery cells:

  • Type: EVE LF90 (3,2V 90AH, Nominal)
  • Datasheet No.: LF90-73103
  • Cut off Voltage: 3.65V/2.5V
  • Std. charge/Discharge: 1.0C

• Power Meter:

  • Type: Tasmota based smart meter from Hitchi

• Controller:

  • ESPRESSIF ESP32-WROOM-32U DEVKITC(with ext. Antenna)

• CAN interface:

  • Driver IC: SN65HVD230

• RS485 Serial interface:

  • Driver IC: Max485 CSA (2 pcs. for BMS and Inverter)

• 0.96 inch OLED IIC 128x64 Display:

  • Driver: SSD1306
  • I2C Addr.: 0x3C

• Temperature Sensors:

  • 1-Wire
  • Type: DS18B20 waterproof

External connectors:

USB upper:

Pin 2 (RXD/D-) Output A Max 485 USB Driver for inverter, Inverter Input A+

Pin 3 (TXD/D+) Output B Max 485 USB Driver for inverter, Inverter Input B-

USB Lower:

Pin 2 (RXD/D-) CAN L

Pin 3 (TXD/D+) CAN H

RJ45:

Pin 1 (Pair 3) Output A Max 485 USB Driver for BMS, BMS Input A+

Pin 2 (Pair 3) Output B Max 485 USB Driver for BMS, BMS Input B-

6 pin connector:

Pin1 GPIO26 Temp Sensor

Pin2 Ground

Pin3 +3V3

Pin4 NC

Pin5 NC

Pin6 NC

Pinning Controller

Information:

Power Equation for the whole house: $\ ActGridPower + ActBatPower + SolProd = Used Power$

JSON help: https://arduinojson.org/v6/assistant/#/step1

ESP32 infos: https://www.upesy.com/blogs/tutorials/how-to-connect-wifi-acces-point-with-esp32

BSC (Battery Safety Controller) homepage: https://github.com/shining-man/bsc_fw

JK-BMS Protocol: https://github.com/jblance/mpp-solar/issues/112#issuecomment-850585642

JK-BMS collection of NEEY: https://github.com/NEEY-electronic/JK/tree/JK-BMS

Known issues:

Solution for Littlefs error: pio pkg update -g -p espressif32