This device can send "door open" command to intercom main unit after receiving of incoming call. It only works with coordinate line intercoms. Tested with Eltis russian intercom.
- NodeMCU v3 x 1
- Double relay module x1 (or two single relay modules)
- LED x3
- Button x2
- Some resistors
- One diode
- Plastic housing
- Blinks slowly when Wi-Fi is connecting
- Blinks faster when MQTT client is connecting
- Steady on when ready
- Steady on when incoming call detected
- 'O' - door open command
- 'N' - call reject command (door will not open)
- 'P' - ping command (answers with 'R')
- 'R' - ready; sent after successfull boot-up or after receiving of 'P' message
- 'C' - call; sent after detecting of incoming intercom call
- 'H' - hangup; sent after detected incoming call finished
- 'B' - button; sent when "door open" has been performed by green hw button press
- 'J' - reJected; sent when incoming call has been rejected by red hw button press
- 'S' - success; sent in response to 'O' or 'N' command
- 'F' - fail; sent in response to 'O' or 'N' command (this means that 'O' or 'N' command has been received but no incoming call detected)
- 'L' - last will message; send when device goes offline