I am trying to control an amplifier (Devialet brand, which provides for a serial command interface) from my home automation system (Openhab running on Windows). I want to use a D1 mini that will be connected directly to the amp, and commands will be sent to the D1 mini through MQTT. I believe that I have already nailed down the software part correctly. For example, if I bypass completely the amplifier by connecting together the RX and TX pins of the D1 mini, I can see that any amplifier command issued by Openhab does get published on MQTT and is then published back by the D1 mini (in place of the amplifier response).
Assuming that the software is OK, what remains to be clarified and executed is the hardwired connection between the D1 mini and the amp. The Devialet serial connection uses a 3.5mm minijack with TX, RX and GND signals. According to Devialet the spec is as follows:
- +5V to +12V for positive signals
- -5V to -12V for negative signals
What I think I understand. but I need to check with you, is whether or not I can simply use the following "RS232 to TTL Adapter MAX232":
https://www.amazon.ca/-/fr/adaptateurs- ... uage=en_CA
And if so, whether or not you think it will be OK to simply send the 3 Devialet signals (RX, TX, and GND -- no VCC) to the female DB9 on one end and connect 4 D1 pins on the other end of the adapter: TX, RX, GND and 3.3 VCC.
Thanks in advance.