search

nic6911 / ESP32_Modbus_Module

54 stars 8 forks source link

Request for help with wiring #8

Closed Fredy72 closed 5 months ago

Fredy72 commented 5 months ago

Here it is written about connecting the power supply directly from the CTS602, where, among other things, +12V and GND are output.

https://github.com/nic6911/ESP32_Modbus_Module/raw/main/electronics/connection.png

Here is a picture of the LILYGO® T-CAN485 wiring in the Nibe heat pump, where PIN9 = GND and PIN12 = +12V (PINs 10 and 11 are Modbus).

https://github.com/elupus/esphome-nibe/blob/master/examples/lilygo-t-can485.png

I own a LILYGO® T-CAN485 and would like to wiring it up to the CTS602 and powered directly from the CTS602 to the PINs 1,2,3,6. Pin1 = 12 VDC output Pin2 = COM1 - RS 485 Data+ (A) - Modbus Pin3 = COM1 - RS 485 Data- (B) - Modbus Pin6 = GND

The electrical diagram of the Lily device is as follows.

https://github.com/Xinyuan-LilyGO/T-CAN485/blob/main/doc/schematic.pdf

I want to ask if it is possible to use the connection in Nilan as pictured with Nibe, i.e. the GND on the RS485 connector (middle PIN) would not be connected (it is written in the first link: "but keep minimum 1x GND on Nilan in all cases!")? Thank you for your answer.

nic6911 commented 5 months ago

Hi,

IMG_4993

page 4 in the Nilan modbus manual: https://www.nilan.dk/Files/Files/Dansk/Downloads/7.%20Modbus%20-%20BACnet/2021-01-Modbus_CTS602_w_HMI350T_Modbus.pdf

Fredy72 commented 5 months ago

Thank you for your response. So are any of these options correct? In the picture at Nibe it is like this: v1 As an alternative, I thought of this: v2

Fredy72 commented 5 months ago

Another way would be to use the USB output from the CTS602 board to USB LilyGo to power the LilyGo. Would it work?

nic6911 commented 5 months ago

I don't know if the CTS602 has the USB power (or can power back through USB at all) to support that board you have there. With the wiring I can only refer to the doc from Nilan which states that you must use GND. If the GND and RS485GND on the board you have there are tied together I dont know... So the wiring would depend on that.