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alessandromatera / SDM230-emulator-growatt-esp-mqtt

An SDM230 meter emulator with an ESP8266 that communicates with a Growatt inverter via RS-485 enabling power export limitation functions
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Connection scheme #1

Closed Diddlik closed 1 year ago

Diddlik commented 1 year ago

Hi, I am currently using the self-designed stick (https://github.com/Diddlik/USB_Dongle_ESP8266_Max485) to read out Growatt with ESPHOME. The next step is to make the export limit. Could you roughly sketch how your scheme looks like how to connect everything?

alessandromatera commented 1 year ago

Hi @Diddlik, here's the schematic https://github.com/alessandromatera/SDM230-emulator-growatt-esp-mqtt/raw/main/Connections.png

I powered the system with the USB port of the inverter.

I hope it helps

Diddlik commented 1 year ago

@alessandromatera And how do you read a values from Growatt? The seconde one esp connected to pin 3/4?

alessandromatera commented 1 year ago

@Diddlik I actually use another ESP8266 device which is connected directly through the USB port, which also powers the other ESP I use for the power limitation functions. For readings I used this repo: https://github.com/otti/Growatt_ShineWiFi-S

I think that I could use the same device which reads from USB and controls the power limitation through RS485.

If you want to use the RS485 protocol also for the reading part, since - at least in my growatt inverter - there are two different 485 ports for readings (pins 3 and 4) and for the SDM230 meter (pins 7 and 8), you should get two different RS485-TTL converters connected to different ESP pins.

alessandromatera commented 1 year ago

@Diddlik Also, in the case you want to read from RS485, remember that for the reading ports your ESP behaves as a master and the Growatt as Slave, meanwhile for the Power Limitation Functions, The growatt is the master and the ESP is the slave.

Diddlik commented 1 year ago

@Diddlik I actually use another ESP8266 device which is connected directly through the USB port, which also powers the other ESP I use for the power limitation functions. For readings I used this repo: https://github.com/otti/Growatt_ShineWiFi-S

I think that I could use the same device which reads from USB and controls the power limitation through RS485.

If you want to use the RS485 protocol also for the reading part, since - at least in my growatt inverter - there are two different 485 ports for readings (pins 3 and 4) and for the SDM230 meter (pins 7 and 8), you should get two different RS485-TTL converters connected to different ESP pins.

Ok, thank you for quick reply. It seems, in all cases I need to use two devices. One for reading (USB from Growatt or RS485 from Pin 3/4) and one for Limitation (pin 7/8). So, it is time to design a new device, that can handle it. Best case:

  1. ESP perform reading from growatt (usb or RS485 Converter)
  2. The same ESP perform as Power Meter and set the limitation over the second ES485 Converter
alessandromatera commented 1 year ago

Great! keep me posted!