Feb 3, 2024

Flashing Tasmota onto a Wifi sensor controller (MHCOZY TH1CH-B1RF)

Today i got a MHCOZY TH1CH-B1RF and installed tasmota:

MHCOZY TH1CH-B1RF is a Wifi temperature and humidity controller:
Product details say:

Users can add the device to the APP eWeLink in order to remotely control connected home appliances or devices. In self-locking mode, customers can remotely turn on/off connected devices immediately. When in inching mode, customers can have two wiring ways to select: * Turn on 1s and then auto-off,* Turn off 1s and then auto-on.

Of course you can stay with the original software, but then you have to integrate EWELINK to you enviroment (which uses port 5353 with some strange multicast mechanism). I want to get the values via HTTP. So the questions is: Can this hardware run tasmota?

If you open this device, you see, that the chip is a PSF-Bxx:

(picture is a screenshot from here: https://templates.blakadder.com/PSF-B.html)

With knowing that, Tasmota can be flashed onto this device:
(all the connects are a little bit tricky, because there are no plugs and you have to constantly touch the contacts with the pins)

  1. Connect GPIO0 with ground (you can use the shielding of the USB connector on the board) 
  2. Insert power via the USB connector
  3. after 5 seconds remove the connection from GPIO0 to ground
  4. connect your serial programmer TX --> chip RX
  5. connect your serial programmer RX --> chip TX
    (i always start with TX --> TX and RX --> RX, which is wrong 🤐 ) 
  6. open tasmotizer.py
    (for installation look here - i chose option 2)
  7. if you choose "backup - save original firmware", then you have to start after the backup with step 1 again.
  8. choose "release" and "tasmota.bin"

  9. click "Tasmotize!"

After a reboot change to the new Wifi "tasmota....XXXX" and enter your Wifi credentials there on 192.168.4.1. And after a reboot you can open the web GUI like this here:

 

(the DHT11 sensor has to be selected for GPIO14)

Now i can get the values via

curl 'http://192.168.178.107/cm?cmnd=status%2010&user=admin&password=XXXX'

"StatusSNS":{"Time":"2024-02-03T19:19:29","DHT11":{"Temperature":24.3,"Humidity":50.0,"DewPoint":13.2},"TempUnit":"C"}}