Help with connecting two or more board relays with esphome rs485

[Kentrp]

Hi! I use your esphome .yaml code to flash my 8 relays boards, its work fine, but now i want to connect them between themselves with RS485 2 wires (i want to connect one master board to Ethernet and other boards to connect to the master use RS485 port) , and don't know how to do it, ill be appreciate you to help me, thank you

[kecajtop]

Hi! Esphome is natlivly supporting RS485 master side. That stuff is very easy to do. I have done it before

sensor:

• platform: modbus_controller modbus_controller_id: epever name: ${friendly_name} Temperature id: temperature register_type: read #0x04 address: 0x0001 unit_of_measurement: "C" value_type: S_WORD accuracy_decimals: 1 filters:
  • multiply: 0.1

To use esphome as a modbus slave is more tricky. You might need modbus server. I know it sound wrong but RS485 master is a client and the RS485 slave is a server.

modbus_server:

• id: modbuserver uart_id: mod_bus flow_control_pin: 33 address: 2 # slave address holding_registers:
  • start_address: 79 # starting register range default: 82 # default value for all those registers number: 10 # number of registers in the range on_write: | ESP_LOGI("ON_WRITE", "This is a lambda. address=%d, value=%d", address, value); return value; on_read: | # called whenever a register in the range is read // 'address' contains the requested register address // 'value' contains the stored register value ESP_LOGI("ON_READ", "This is a lambda. address=%d, value=%d", address, value); return value; // you can return the stored value or something else.
  • start_address: 200 # in this example we map register 200 to a switch number: 1 on_write: | if(value) id(relay_1)->turn_on(); else id(relay_1)->turn_off(); ESP_LOGI("ON_WRITE", "This is a lambda. address=%d, value=%d", address, value); return value; on_read: | ESP_LOGI("ON_READ", "This is a lambda. address=%d, value=%d", address, value); return value;

It will require few tries and errors. Debuging will be very helpulf (ESP_LOGI). Additional RS485 to USB cable might be also requaried. Sorry if I cannot be more helful but my board is not accesable at this time so I cannot make any mockups to test it.

[Kentrp]

Hello! I need one more help, how to write binary sensors and sensors in modbusserver i can't get it work correct, thank you

[kecajtop]

Hi,

What would be your address and register number?

[Kentrp]

It's doesn't matter i just need example (slave address 2 register numbers 210-220)

[Kentrp]

#######Master board modbus_server:

• id: modbuserver uart_id: mod_bus address: 2 # slave address holding_registers:
  • start_address: 79 # starting register range default: 82 # default value for all those registers number: 10 # number of registers in the range on_write: | ESP_LOGI("ON_WRITE", "This is a lambda. address=%d, value=%d", address, value); return value; on_read: | # called whenever a register in the range is read // 'address' contains the requested register address // 'value' contains the stored register value ESP_LOGI("ON_READ", "This is a lambda. address=%d, value=%d", address, value); return value; // you can return the stored value or something else.
  • start_address: 200 # in this example we map register 200 to a switch number: 1 on_write: | if(value) id(relay_1)->turn_on(); else id(relay_1)->turn_off(); ESP_LOGI("ON_WRITE", "This is a lambda. address=%d, value=%d", address, value); return value; on_read: | ESP_LOGI("ON_READ", "This is a lambda. address=%d, value=%d", address, value); return value;
  • start_address: 201 # in this example we map register 200 to a switch number: 1 on_write: | if(value) id(relay_2)->turn_on(); else id(relay_2)->turn_off(); ESP_LOGI("ON_WRITE", "This is a lambda. address=%d, value=%d", address, value); return value; on_read: | ESP_LOGI("ON_READ", "This is a lambda. address=%d, value=%d", address, value); return value;
  • start_address: 202 # in this example we map register 200 to a switch number: 1 on_write: | if(value) id(relay_3)->turn_on(); else id(relay_3)->turn_off(); ESP_LOGI("ON_WRITE", "This is a lambda. address=%d, value=%d", address, value); return value; on_read: | ESP_LOGI("ON_READ", "This is a lambda. address=%d, value=%d", address, value); return value;

Slave board:

• platform: modbus_controller modbus_controller_id: epever name: "0" id: relay_9 register_type: holding address: 200 bitmask: 1

Its work ok with switch, but i need to get binary sensors and temperature sensors, ill be appreciate for help

[kecajtop]

Did you sove this problem?

[Kentrp]

No, i don't know if it possible to do, i want to use pin for Dallas 18b20 sensor

[kecajtop]

Are you good in soldering?

[Kentrp]

Are you good in soldering?

Yes I am

[kecajtop]

Are we still talking about modbus problem or just temp sensor? Are you using ethernet port as well or just wifi?

[Kentrp]

Yes want to connect sensor to relay and if it possible to send data from one to another relay using rs485 ( modbus) I use ethernet in one relay and wifi in another one

[kecajtop]

You might need to use spear pins. I did that before for i2c display

i2c: sda: 4 scl: 5 scan: true id: bus_a frequency: 400kHz

so for dallas chip

sensor:

• platform: dallas address: 0x5f000000560bdf28 # id can be obtained from logs on first boot name: ${friendly_name} Temperature

dallas:

• pin: GPIO4 update_interval: 10s

Don't forget 4.7k pull up resistor to 3.3V

[kecajtop]

Or you can use RX pin you just need to disable uart logs

[Kentrp]

It’s mean to connect dallas sensor to i2c pin 4 data wires?

[Kentrp]

Or you can use RX pin you just need to disable uart logs

I used this pins in other projects like binary sensor and relay after power off dead i need to reflash it

[Kentrp]

Im interesting to use input to connect sensors, its easy to connect using available contacts

[kecajtop]

try to use pin 4 platform: dallas address: 0x5f000000560bdf28 # id can be obtained from logs on first boot name: ${friendly_name} Temperature dallas:

pin: GPIO4 update_interval: 10s

[Kentrp]

We’re is pin 4 in relay

[kecajtop]

bottom right corner pin 26

[kecajtop]

I will try dallas pin tomorrow. My unit is not easly accessible.

[kecajtop]

I made some progress last evening. I was able to send some intigiger value of the internal temp sensor via modbus.

[kecajtop]

[kecajtop]

modbus_server:

• id: modbuserver uart_id: mod_bus flow_control_pin: 33 address: 2 # slave address holding_registers:
  • start_address: 79 # starting register range default: 82 # default value for all those registers number: 10 # number of registers in the range on_write: | ESP_LOGI("ON_WRITE", "This is a lambda. address=%d, value=%d", address, value); return value; on_read: | # called whenever a register in the range is read // 'address' contains the requested register address // 'value' contains the stored register value ESP_LOGI("ON_READ", "This is a lambda. address=%d, value=%d", address, value); return value; // you can return the stored value or something else.
  • start_address: 200 # in this example we map register 200 to a switch number: 1 on_write: | if(value) id(relay_1)->turn_on(); else id(relay_1)->turn_off(); ESP_LOGI("ON_WRITE", "This is a lambda. address=%d, value=%d", address, value); return value; on_read: | return (id(temp_sens1).state)*100;

sensor:

• platform: dallas address: 0x000000000000000 # id can be obtained from logs on first boot name: ${friendly_name} Temperature id: temp_sens1

dallas: pin: GPIO4 update_interval: 10s

[kecajtop]

[Kentrp]

Hi can it send more then 1 data sensors through modbus

[kecajtop]

[kecajtop]

Did it work?