In order to be able to flash the device from the pins, make sure to disconnect the front panel from the rest of the device. If not done, the tuya MCU will prevent the ESP chip to be flash.
All dimming and on/off functionality is controlled by an MCU that does not follow the Tuya protocol. Dimming and on/off can be set by Tasmota using simple serial commands. Reading local dimming when set by the capacitive touch panel requires a Script-enabled build and the script below to process serial status codes sent by the dimmer MCU.
Status codes take the form of 24xx012123, with xx ranging from 01 to 64 (hex 1-100).
Minimum dimming level may vary by light fixture - adjust the ‘off’ value to match your setup in the >D section.
>D 100 rng=235 dimh="" slider=0 power=0 dimval=1 a="" b="" c="" d=0 f=0 g="" ;set the hex code below to the largest value possible that will turn off the relay with SerialSend5 off=0x7f >B dp0 rng-=off =#scDim(dimval) >E a=SerialReceived if sl(a)>0 then g=sb(a 0 2) if sl(a)==47 then b=sb(a -5 2) else b=sb(a -8 2) endif a="" if g=="24" then f=hd(b) =>dimmer %f% slider=f dimval=slider =#scDim(dimval) =>SerialSend5 %dimh% endif else slider=Dimmer if chg[slider]>0 then ; dim according slider if slider>0 and dimval!=slider then dimval=slider =#scDim(dimval) =>SerialSend5 %dimh% endif endif endif if pwr!=power then if pwr==1 then =>SerialSend5 %dimh% power=1 else =>Serialsend5 00 power=0 endif endif #scDim(dimval) dimh=hn((rng*dimval/100)+off) =>print Scaled brightness is %dimh%
Alternatively, you can flash with a 9.0.0 version of tasmota customized for this switch. It is a bit simpler, since it requires no scripting, just choosing the module Gosund Dimmer (76), and fixes a bug in this setup. Discussion is here: http://cocoontech.com/forums/topic/32175-gosund-wifi-dimmer-replacing-firmware/page-3 amd the binary can be found here: https://github.com/gbg108/Tasmota/releases/tag/v18.104.22.168_GS1.1
2021-10-11 Bought on Amazon pack of 2 switch dimmer. Model is written DS1. try All the info with special firmware or with the latest tasmota + the script and the dimmer does not correctly work. look like the gosund DS1 is and upgrade of SW2 and some hardware change prevent working correctly with provided infos, waiting to get update to fix