Error 501 Whilst flashing the Shelly Dimmer 2 STM firmware

Hello,

First of all, sorry that the message is not in German as I noticed that most users are writing in German. I do understand German and speak it quite well, it's just that writing this message in German would be a complete massacare..

Feel free to answer in German if that'd make it easier to write.

I've been using a few Shelly devices in an OpenHAB system and decided to use these devices with tasmota. I have some experience using the Shelly Dimmer 2, Shelly 1 and Shelly 2.5.

I've also am busy trying to get a Power Meter based on a ESP8266 to work with the dutch smart meter and smart up my ikea desk with mqtt, preferably tasmota as I'm getting more and more familiar with it.

Now I have successfully flashed a few Shelly Dimmers 2, but there is one perticular Dimmer that is being a bit weird in it's behaviour. Flashing tasmota is going well but as soon as I try to update the STM (shelly-dimmer-stm32_v51.6.bin) firmware via the OTA firmware upgrade I receive error 501 when i hit the upgrade button.

I followed the guide from https://templates.blakadder.com/shelly_Dimmer_2.html for all my Shelly Dimmers but for some reason this one unit is being stubborn.

As for a sanity check I tried an other Shelly Dimmer 2, reset it completely with new Tasmota firmware repeated the steps and voila, this one works like a charm (as it did with the previous 5 Shelly's) but one is showing the anomaly as inserted as image at the bottom of the post.

What I tried:

- [OTA] Older Tasmota firmware versions (9.0 - 9.2 - 9.3 - 9.5 - 9.5_development).

- [OTA] The other STM firmware (V51.5)

- [FTDI] Reflashed it with Tasmota several times

- [FTDI] flash the STM software but it leaves the tasmota broken

What I still need to try:

- Flash the original shelly firmware back to see if the STM is not bricked/broken?

Anyone ever experienced this?

Any suggestions why this error occurs or a way to fix this?

Thank you

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Best regards,

Wesley

In addidtion to this topic I've uploaded the original firmware but there's still no cigar there.

After following the reverting to original firmware I've managed to flash the original shelly dimmer 2 firmware to see if that would coorperate.

The Shelly firmware is on there and the device generates a WiFi network.

When connecting to this network by phone and opening the shelly app nothing happens..

The device is not found and can not be manually added by IP even when it is only connected to the shelly wifi.

When manually going to the IP I get greeted by the contents of the shelly:

chrome_2021-07-27_00-07-07.png

As soon as I open the index.html.gz the device opens a shelly page but immediately starts complaining about not being able to fetch the device settings.

chrome_2021-07-27_00-07-33.png

Clicking on the buttons of the web page to configure timezone, internet etc also seem to be broken as nothing happens / gets loaded. Only an error whe.n opening actions which is that no actions can be loaded.

Last but not least the calibration. Hooked up a simple light bulb and tried to open the calibration. it immediately states that it cannot execute the calibration.

One thing I do notice when plugging the device to mains is that the lightbulb goes on fully very shortly <100ms and after starts glowing very dim, and not being able to be controlled by the slider and/or power button.

chrome_2021-07-27_00-14-28.png