Combining multisensor and sonoff

In my kitchen I have 2 sonoffs. One in the overhead ceiling lamp (the wall switch didn’t have the ground/earth wire)

There is another sonoff attached to a wall mounted “tv” from reusing a pc monitor and a firestick 2nd gen.

In order to save a sonoff and place it elsewhere as well as centralizing all the iot in one spot I though I’d take a

  • Nodemcu v2
  • Single Relay 10-15A@110v
  • DHT22
  • PIR AM312 x2
  • MQ2 sensor (I had lying around)
  • <maybe> IR transmitter (as my ceiling light apparently is supposed to have a remote control)

Using a previously flashed Tasmota nodemcu I decided to wipe it clean using a 1MB blank file and flashing it at 0x00000, 0x10000, 0x20000, 0x30000 using the ESP8266Flasher

There is also the nodepy (?) that does a proper erase I think.

Flashing Tasmota worked but nothing appeared. No sonof wifi AP.

I ran into trouble flashing so I decided to do it again and flash using the software default settings. 9600baud. Which is way too slow.

The I flashed the latest 6.6.0 Tasmota on using 57600 baud and it finally worked and the sonoff AP appeared.

I’ve played around with the relays before. I have converted BRUH to Tasmota Before.

This relay portion is no longer accurate. New entry being written at the moment.

But one thing that I seemed to have not done is test the single relays. As the relay is central to the conversion I started to breadboard test.

And then nothing. Connecting the nodemcu to the signal pin of the relay resulted in the relay being stuck in the open position. Solution found

The toggle button in Tasmota was ineffective. Whatever Tasmota toggle button displayed was moot.

This was at 1AM a bad habit of trying to think of things when tired.

It later (next morning) dawned on me that the single relay had markings below indicating low voltage.

Low level trigger

Ahhh ok. So as in the picture above I tried a 10k resistor and voila it worked as normal.

In retrospect this is called a pull up resistor.

Other relays (double and quad) don’t seem to have this issue and work directly with the pin outputs of the nodemcu.

It’s small but on the right (single) relay there is “low level trigger”

There is a glowing red light top right of the pic. It’s an MQ2 sensor that I decided to finally use at I bought it over a year ago to detect kitchen smoke and gas I guess.

This eventually failed as the relay was inadequately powered.


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