Another question about Sonnoff DUAL R2

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mackowiakp
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Another question about Sonnoff DUAL R2

#1 Post by mackowiakp » 16 Mar 2022, 03:54

Is it possible to use TX and/or RX serial port pins as additional input/output for push-on switch in ESPEasy FW?
If so, whats are GPIO numbers of TX and RX pins?
Serial port is disabled in ESP setup.
I can not use already present onboard solder plates labelled as Button1 and Button2 because I use it for I2C bus for BME680 sensor.

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Ath
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Re: Another question about Sonnoff DUAL R2

#2 Post by Ath » 16 Mar 2022, 07:44

mackowiakp wrote: 16 Mar 2022, 03:54 I can not use already present onboard solder plates labelled as Button1 and Button2 because I use it for I2C bus for BME680 sensor.
It is more common to do that the other way around, so use RX/TX for (I2C) sensors, and leave the buttons as is. I'd try to avoid bringing the buttons of a Sonoff outside the housing, for reasons already mentioned, electrical (un)safety, because any connection inside is relative to mains.

This is how I've setup my Sonoff S20's that have a BME280 built in, connected to RX/TX:
Screenshot - 16-03-2022 , 07_39_00.png
Screenshot - 16-03-2022 , 07_39_00.png (4.54 KiB) Viewed 6038 times
It's also quite easy to disconnect for updates because I've just pushed the (short) Dupont wires on the header I installed for the serial connection.
/Ton (PayPal.me)

mackowiakp
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Re: Another question about Sonnoff DUAL R2

#3 Post by mackowiakp » 16 Mar 2022, 09:07

Thanks a lot for your quick reply.
However, I would like to clarify one thing.
because any connection inside is relative to mains.
It is true in case of single channel Sonoff, POW ver and many others.
But my copy of Sonnoff DUAL R2 has onboard "ordinary" power supply circuit which totally isolate from live main (230V) any internal parts or externally connected sensor or so. (see picture).
Even it is possible to buy additional housing for Sonnoff DUAL R2 which meats IP65 waterproof class.
IMG20220316085532.jpg
IMG20220316085532.jpg (3.16 MiB) Viewed 6032 times

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Ath
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Re: Another question about Sonnoff DUAL R2

#4 Post by Ath » 16 Mar 2022, 11:14

The PCB design is quite close to other Sonoff designs I've seen so far, so I don't have much confidence in their claim of isolation (the distance between the traces and mains/high-voltage components isn't that wide, it appears). That's why I keep warning for these risks. Better safe than sorry :mrgreen:
/Ton (PayPal.me)

mackowiakp
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Re: Another question about Sonnoff DUAL R2

#5 Post by mackowiakp » 16 Mar 2022, 13:40

Yep. Security first !
zlew.jpg
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