The two pins and put it into flash mode again. In other cases the TX and RX pin are reversed. To plug the device into a socket to overcome this problem while troubleshooting. Simply connect the NodeMCU’s 3.3V to VCC and GND to GND. A nice hack is to use the power supply of Sometimes the UART bridge cannot supply enough current to the chip to operate, in thisĬase use a 3.3V supply you have lying around. If above step does, however, not work, here are some steps that can help: This will all be fixed once you re-assemble your T3Īnd power it up from the mains power once safe to do so. It may flash random LEDs, turn on and off touchpads’ backlight and not react on touching touchpads. While now your T3 will start up and connect to your WiFi network if you power it up from UART it will not behave normally, The Resistors R19, R20 and R21 expose GPIO0, GPIO9 and GPIO10 respectively. Provided you are not touching any live contacts, only the wires. There’s no need for soldering - for quick job like one time firmware flashing you can just hold pins in respective holes by hand

VCC33 should be connected to the 3V3 ( not 5V) pin of the UART bridge, GND to GND That you connect these correctly, especially the VCC33 and GND parts as you can otherwise Now go ahead and connect these pins to your UART to USB bridge as seen in below image. These by the VCC33, RX, TX and GND markings on the silk-screen. Have to connect the four wires on the UART to USB bridge to the UART pins of the Sonoff T3 v1.0.įortunately for us, these pins on the ESP controller have dedicated solder pads on the PCB ( J3). Now we need our computer to somehow establish a data connection to the board. “TOUCH BOARD” with touchpads holds the ESP chip.

This PCB contains the ESP chip and what’s left inside the switch body are relays. With careful twisting motion detach the faceplate.Īfter that, use the same screwdriver to carefully lift the top PCB off of the switch. While the device is not plugged in, turn the device face down and put a narrow flat screwdriver into the slot at the bottom. Just to repeat this: Make absolutely sure the device is not connected to any appliance or Supplied with the Sonoff T3 EU 3 Gang before doing this step. Note that you do not have to run the original firmware The first step is to open up the Sonoff T3 EU 3 Gang.

Step 1: Opening up the Sonoff T3 EU 3 Gang ¶ Have everything? Great! Then you can start. Screwdriver to open up the Sonoff T3 EU 3 Gang. Jumper wires to connect the UART bridge to the header pins and to connect GPIO0 to the Ground.Ĭomputer running ESPHome or the Home Assistant ESPHome add-on. Note that the bridge must be 3.3V compatible. These can be bought on Amazon for less than 5 dollars. It’s your own responsibility to make sure everything you do during this setup process is safe.Ī USB to UART Bridge for flashing the device. With continuing, it’s best to just stop for your own safety. If you, at any step, feel something is wrong or are uncomfortable So, during this entire guide never ever plug the device in. You will be a single touch away from being electrocuted if the device is plugged in. Opening up this device can be very dangerous if not done correctly.

Edit sonoff bin file