ESP32/8266/12E implementation of Unifon digital domfon/intercom
NO
Witam, chyba nigdy
I think never. It is hobby project :)
I'll share my learnings here.
- L+ is analog, 0-11V
- L- is GND
- digital domofon - it is only the name. It is still analog in practice.
ESP works only on 3.3v. Intercom is working on 11v. Some resistors is needed. My setup:
---
title: Connection diagram
---
flowchart TB
eGND[GND]
iGND[L-]
iLP[L+]
eD1[D1]
R1[Resistor 10kΩ]
R2[Resistor 3.5KΩ]
eGND<-->iGND
R1<-->iLP
R1<-->eD1
eGND<-->R2
R2<-->eD1
subgraph Intercom
iGND
iLP
end
subgraph Wires
R1
R2
end
subgraph ESP8266
eGND
eD1
end
In IDLE mode, L+ is low state
In dialling mode L+ starting be UP. And then we have 58ms to count all Edge falling. Count of edge falling is dialled number.
After 58ms of dialling, the event type need to be detected.
- ringing: 500uS interval
- wrong gate pin: 280uS interval, 530uS cycle
- correct gate pin: 218uS interval , 424uS cycle
Solution implemented: Wait after dialling for next pull-up, start counting pull-ups for 10ms.
- 10 ±1 = calling
- 5 ±1 = wrong gate ping
- 23 ±1 - correct pin
Cancelling signal (call & press (C) Key) looks like 10ms UP state, and then failing to 50% of signal.
- after pickup the intercom, detected signal how call is ended
- after pickup the intercom, detected opening the gate signal.
- detect how procedure of wrong pin & correct pin is ended.
- detect how to pickup the call.
- implement two way voice communication
- find some ADC/DAC working with 10 voltage or any other solution