Martin Jerry MJ S01 to Tasmota


Purchased at Amazon for around $13.00
I installed one Gosund non dimmer switch a few months back in house #2.  Rest of the switches are Gosund Dimmer switches.  The non dimmer switch was updated to Espurna using Tuya Convert which worked fine.  Decided to switch it from Espurna to Tasmota using the GUI firmware update tool.  It bricked the device.  Looked inside and all I see are soldering pads on the 3.3v, RX, TX and Ground.  This then will wait for a time and purchased a Martin Jerry MJ S01 switch.  
I installed TuyaConvert on my Linux Laptop.

git clone
cd tuya-convert

Start flashing process:
Execute ./ and follow the instructions. It will install our flash loader onto the ESP and connect to the access point created by your wifi adapter. A backup of the original firmware will be automatically downloaded and stored locally. You can then proceed to flash your desired firmware or revert to the stock firmware.
If you flashed the included Tasmota firmware file, it will broadcast a tasmota-xxxx access point (AP) when the device boots. Connect to this AP and open the browser to to configure the device's Wi-Fi credentials. When entering the Wi-Fi password, click the checkbox to view the password you enter to ensure that it is correct and that your mobile device has not inadvertently capitalized the first letter if it is supposed to be lower case nor autocorrected what you entered. Double Triple check the Wi-Fi credentials before clicking Save to apply the settings.
Installed template:

{"NAME":"MJ-S01 2Way Switch","GPIO":[1,1,1,1,288,321,0,0,224,32,544,1,0,0],"FLAG":0,"BASE":18}

If a Red LED while Off and Blue LED while On is desired paste the following rule into the Tasmota console.  If you want opposite colors, edit the template in the configure template screen and transpose Led_i with Led and vice versa. The "i" stands for inverted.  Copy the below rule as one line to the Tasmota console:  

Rule1 on power1#state do backlog ledpower1 %value%; ledpower2 %value% endon
      on power1#boot do backlog ledpower1 %value%; ledpower2 %value% endon

In the console type: rule1 1
Easy Peasey stuff.
Also installed a Sonoff TH10 converted to Tasmota.  This provides Temperature and Humidity levels in House #2 separate from the Thermostat.
With those connections available on the bricked device, I think you should be able to flash tasmota using the more traditional method - using a usb to serial converter and physically connecting it to the IOT device.  Obviously using Tuya-Convert is easier because you can flash it all OTA and not have to open up or physically make connections to the IOT device, but the traditional method allows you to recover "bricked" devices usually and there are actually fewer and fewer devices that work with Tuya-Convert.  (The newer wifi chips fixed the bug that allowed Tuya-Convert to work in the first place). Where as using the traditional method is almost guaranteed to work.
Thank you @sic0048.

Smallest traces I have every seen. No holes in any of the soldering traces.  The MagicHome controllers I JTAG'd had larger traces.
Using 26 guage very thin wire and have the 3.3VDC and Ground so far connected.  Next is the RX, TX and GPIO-0 traces.
It is hard to read the print next to the traces.
I tested the 3.3VDC / ground and they work fine with the board.  One LED flashes once when I do this and that is the same as  before with the 120VAC voltage.
It is still bricked so the JTAG should work.  Meanwhile the Martin-Jerry relay switch was very easy to program with Tuya-Convert.  Never took it apart.
The print is so tiny I am using my workbench magnifying glass and lamp to do this and the smallest soldering tip I have.
I tinned the traces and wires before I started.  Then heat the wire as I touch the trace.  I am also using my little clamps / helpers and mounted the board on my holder / clamp.
Will post pictures of the soldered wires after updating the device to tasmota.  I should have just put the Espurna Gosund in to programming mode and used Tuya-convert.
Installed the Martin Jerry switch this afternoon.   The plate on it is very thick.  It is a triple switch box with two other switches.  I will need to purchase a Leviton "thick" wall plate for it as it makes the current wall plate stick out a bit from the wall.
If I fix the Gosund switch and bring it to Tasmota will install that switch again.
Updated the Gosund WS1 with Tasmota.  Real PITA to solder the wires.
1 - connected GPIO 0 to ground
2 - connected RX, TX and 3.3VDC to TTL USB programmer
The above will boot in in programming mode.  You do not have to remove GPIO0 from ground.
I did this in Ubuntu Linux (laptop) using Tasmotizer for Linux.
1 - pip3 install --upgrade pip wheel
2 - pip3 install tasmotizer
then just run ./
I was initially very reluctant to open up my devices and flash Tasmota using the traditional method (direct connection to the chip pins).  I used Tuya-Convert instead and that is obviously still the desired flashing method because it is so much easier.  But once I "bricked" a couple of devices, I bit the bullet and flashed them using the traditional method.  As you noted, it can be hard to solder to the IOT device.  If you have a 3d printer, you can print a jig that is sized to fit over the actual wifi-chip and you use pogo pins to make the connections.  No soldering required!
Thank you @sic0048
I purchased a couple of jigs from DigiBlur last year and they worked well. 
Thinking it was the very thin 24-26 guage wire that helped a bunch and new soldering tips for my soldering station.
I didn't know that Tasmotizer worked in Linux / Python...I am more used to working in Linux these days than Windows.
Really did brick this Gosund switch as it would not go to boot mode with the trashed Espurna firmware.  So cheap these days its not really that much of an issue.

Purchased the right driver set for removing the tiny screws which are just a tiny torx screw.

Most of the work for this three gang box was taking a neutral wire up for the duplex outlet below the switch. The conduit was there for the hot lead but no neutral wires. While in the box also added a ground wire for the switch. It is all metal boxes here with metal tubing for electrical wires.
So far very impressed with the combo light / fan switches.  They work well at dimming the Edison style LED lamps I am using now with the fans.
I have not as yet standardized on my WiFi dimmer switches as I am tinkering a lot with them.  They are all the same yet all different designs these days.
I had issues here finding a latching WiFi ESP relay that had any JTAG traces on it a couple of months ago.  I did find the original ESP01 board with the plugin WiFi board and using the socket was able to JTAG the device to Tasmota.
Installed the fixed Gosund switch today in house #2 for garage light which will auto activate when the garage door opens or the entry door to the house opens.
I am using the wireless Ring sensors to trigger the on and off of the Gosund switch.