DS-121 2 Gang No Neutral Switch
DS-121 2 Gang No Neutral

Available from:

Install method:
USB to Serial

GPIO #Component
GPIO00 LedLinki
GPIO01 Led2i
GPIO02 None
GPIO03 Button1
GPIO04 Relay2
GPIO05 Button2
GPIO09 None
GPIO10 None
GPIO12 None
GPIO13 Relay1
GPIO14 Led1i
GPIO15 None
GPIO16 None
Configuration (old format, will be converted to new template when applied)
{"NAME":"2 Gang Switch","GPIO":[158,57,0,17,22,18,0,0,0,21,56,0,0],"FLAG":0,"BASE":18}

Smatrul appears to be the main seller but they are also sold by Avatto (I can confirm that even 99% of the packaging is the same). Tuya convert was attempted and did not work.

Ground GPIO0 during boot. Ground RST as well. (So really that means a 3 pin splitter from GND to GPIO0 + RST + GND of Serial Flasher.)

After clicking “Start” in Tasmotizer, wait 1 second, then UN-ground RST and it will finish the operation. Or make a momentary connection just before flashing starts

I watched the red lights of TX/RX on the Flasher, after clicking “Start” they will flash a few times, then stop briefly. This is the best time to un-ground RST. If it doesn’t go bright red right away, try making a momentary connection. Multiple attempts may be needed.

It may not be necessary to do all this extra work. Try doing a simple 4 pin flash first.