Let's Control It

Today I decided to update the firmware on my devices running ESP Easy, but 2 out of 3 returned FAIL after I send the file to them, and I am wondering why... Here is how I did.

The devices I got is a mix of some different ESP modules (one ESP12, one ESP12E and one custom in the itead smart switch), and the only one updating correct, was the ESP12E.

To find the correct file for the device, I went to the Main page, and looked at the "Flash Size: 4096 kB", and for this I then took the ESPEasy_R108_4096.bin file, and after pressing Update, it took a few seconds, responded with an OK, and then it worked. On the next device, I again went to the Main menu, it said "Flash Size: 1024 kB", so I took the ESPEasy_R108_1024.bin file, and as soon as I pressed Update, it responded with FAIL, and after that I was unable to connect to it again, even after a power cycle it was still unresponsive. The last device to update, returned as the first "Flash Size: 4096 kB", but opposite of the first one working with the ESPEasy_R108_4096.bin file, this one also returned FAIL, and was also unresponsive.

The version I upgraded from was in all cases R78, but only 1 out of 3 worked as expected. Did I do wrong in just going by the "Flash Size" reported on the main page, or do I need to check it another way before sending a file to it?

After attaching the failed devices to a CH340G adapter, I could flash them successfully with the same files which failed OTA.

Things will fail if you start to mix different sizes. I can't tell if that has been the case here.

For instance, the following scenario will not work as expected:

1) Use serial to flash a 512k version on a system with 1024 flash size like the Sonoff. (it will work however with a smaller bin file)
2) Update to a 1024k version using OTA.

To be more clear on this: the bin file size is similar on all versions because there's is actually only one firmware version. The mentioned size in the bin file is only about how the memory layout of the flash chip is used by ESP Easy. If you mix layout sizes on the same ESP module, ESP Easy will not be able to locate the settings after a change and this may lead to unexpected behavior of just a factory reset. Using a 512k memory layout will also not work because the OTA process needs enough free space to download the temporary copy of the firmware.