DETA Grid Connect 3 and 4 Gang Light Switches and Home Assistant

I’ve been using the Deta Grid Connect 1 and 2 gang light switches with Home Assistant for about 6 months now – as mentioned in this post. The 3 and 4 gang switches have finally arrived, and having picked one up from Bunnings, I was keen to get it setup and the firmware replaced with my own.

As mentioned in that previous post, replacing the firmware with ESPHome, your own firmware, or Tasmota has two methods. The first method is to use tuya-convert over WiFi, and the second method is to use the headers on the circuit board to plug your own leads in and upload firmware through a serial connection. Unfortunately, the good people at Deta have removed the headers on the circuit board, and changed the key used by the firmware rendering tuya-convert unusable.

It is only a matter of time though before tuya-convert is updated which will enable a wireless push of new firmware to the device. Luckily though, even without the headers, you can still use a serial connection to the board. The difficulty though, is you either need to solder your own leads on or be a little dexterous. As I mentioned on the earlier post, you need to provide power and ground to the board; you need to connect your serial programmer’s TX and RX; and you need to pull RST and GPIO0 to ground, release RST to boot the device and then release GPIO0 for programming mode.

In order to avoid soldering, or needing 4 hands, you can connect power and ground to the bottom pins on the board. You need to supply 5V though, as the pin doesn’t connect directly to VCC on the chip, rather it connects to the input side of the voltage regulator. So providing 5V on the pin gets you 3.3V on the chip. I used a bread board power supply to get the 5V, and I shared the ground on the bread board power supply to my programmer.

I then used a couple of ground connected leads to hold against RST and GPIO0 to reboot the device. Releasing RST boots the device, and then releasing GPIO0 a few seconds later enables programming mode.

Once in programming mode, I used a little header block with 2 pins bent away, and connected them to TX and RX on my programmer. I then simply held it against the TX and RX pins on the chip while pushing firmware through the programmer.

Once the firmware had uploaded, I released the TX and RX pins, and then pulled RST to ground momentarily to boot the device.

The firmware I pushed to the device supports OTA (over the air) updates, so hopefully that was only a one off activity! The good news is though, you only ever have to hold 2 pins against the chip at any one time in your hand – so its not too difficult even without the header area on the board.

This sometimes takes a few attempts. Sometimes it works first time, sometimes I might have the timing slightly off, or I may not quite have the pins in contact. So be prepared to give it a couple of attempts.

~ Mike

23 thoughts on “DETA Grid Connect 3 and 4 Gang Light Switches and Home Assistant

  1. Hi Mike,

    I’ve just purchased one of these and while the above makes some sense, I don’t understand all of it… any chance you could explain and/or film a little? Just mostly need some advice with regards to boot/program mode and process…

  2. Just confirming I finally worked it out and have successfully flashed a 4 gang switch.

    Appreciate this guide, was great the 4 gang is slightly different although the above pictures are still relevant.

    Cheers

    1. What did you do differently with the 4 gang one – you noted it was slightly different – I couldn’t get it to flash for some reason.

      1. Hi Steve,

        I’ve done it a couple of times now, it’s exactly the same as the 3 gang describe only the board looks different.

        Can you get it to see the ESP? Or are you having a trouble getting it connected?

      2. I’ve not yet flashed my 4-Gang, I’ll be doing that tonight, but I’ve successfully flashed half a dozen different tuya’s over the last 2 days via OTA, I have three of these and several older sonoffs that need to be done serially.

    2. Hi – my usb to serial adapter has a 3.3v pin and 5v. I connected the 5v to my breadboard then connected a jumper lead to the 5v pin on the board per Mike’s picture. Then connected ground of usb to breadboard and jumper wire from breadboard to ground per Mike’s piacture. This gave the board power as the Led lights came on. Then I connected a jumper from ground (negative on breadboard) to rst pin and the lights in the board went out. Then I connected a jumper from ground to the goio00 pin and the led on the board came on steady. I released the rst and then released the gpio00 3-8 seconds Later (tried different times) but as soon as I pulled the lead of gpio00, the led light on the board went out. Then I connected the rx in usb to Tx on board and Tx on usb to rx on board. (Actually tried vice Versa as well and that didn’t work either) While holding the ex/Tx pins in place, I clicked Tasmotise on tasmotiser after having selected the right com port (com3) and the top Tasmota bin release plus the tick box of backup and flash. The backup part my have worked as it put a file on my pc but the download firmware part says failed to connect to esp times out waiting for packet header and sometime I got invalid head of packet ox4f. Either way, nothing downloaded as nothing moved off the zero % in the download bar. Not sure what I’m doing wrong . Strangely, I was able to push the WiFi SSID and password to the device as it said 110kb pushed.

      1. I’ve tried for about 12 hours to get this to work – all my it’s capable devices work but not this one. I’ve tried everything – is there someone I can mail my device to with paid return mail to see if they can make it work. It’s not going into flash mode.

  3. Hi Mike. Wondering if the individual switches be used to control other devices? For example. I’d like to replace a single light switch with a 3-gang. First button will control the existing light via the current wire and give the switch its power, the other two buttons programmed (in home assistant) to run another device elsewhere in the house (maybe trigger a HA automation). Would this type of config be possible with ESPHome or can they only control wired lights?

    Cheers.

    1. Hi Andrew – you could leave one of the output light connections not connected to anything – the software running on the controller doesn’t actually know if there’s something there. You can do a lot of cool stuff with them just as a switch.

      I’ve actually got one connected to a LIFX wifi light. However, its programmed so that when I press the wall switch, it doesn’t actually power off the light, but rather tells HA to inform the wifi bulb to turn off (but it stays powered). If I then hold the light switch down for 3 seconds, it actually powers the circuit off. I’ve got a friend with one where if you hold the button down, it tells HA to turn off all lights.

  4. Just wanted to call out and say that your advise was golden – I bought these from my local bunnings – First one went fine with OTA – second one had the new firmware that had the same issue – Your instructions for wiring were perfect. I just finished documenting my process for my own prosperity but just wanted to call out that it was awesome.

  5. Just reaching out as has others. Great stuff Mike, much appreciated. I’ve been holding off doing an old Sonoff 4ch pro and after doing one of my 2-gangs (serially following your instructions), I went ahead and did a few more, including that Sonoff (which was a tad harder TBH).

  6. Just finished getting an electrician to install 24 DETA smart switches including 1, 2, 3 and 4 gang. All flashed thanks to your guides. Working brilliantly. Thanks for putting this information out there.

    1. I did have one question tho, I assume it’s a simple answer. In Home Assistant, it appears as a switch and a status entity. I am assuming the status is the WiFi signal strength?

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