ESP8266 Community Forum

- Wed Sep 28, 2016 10:47 am #55816 Before any flashing it had version 1.3 of the firmware on it and AT commands worked great. After this I flashed a wifi example Sketch to it and this worked fine as well. That fact is important because my flashing setup works good. I can flash between stock and Sketch without issues. Now I want to flash the eagle.flash.bin back on to revert to the non-os stock firmware where I can execute AT commands again.

1. I am using the latest ESP flasher version 3.4.2
2. I have tried the latest 2.0 sdk and also an older SDK 1.5.4
3. The flash tool reads my ESP and automatically sets the 8mb option. My ESP is blue so I assume it is the 4mb version
4. I flash:
eagle.flash.bin 0x0
esp_init_data_default.bin 0xFC000
blank.bin 0xFE000
eagle.irom0text.bin 0x40000
5. The flash takes 15-20 seconds and completes without errors
6. I restart the module and the light is solid blue
7. I connect to the module and it is sending out constant garbage

I also tried setting 4mb and changing FC and FE to 7C and 7E but it didn't make any difference. I have read many guides and I am not sure what I am missing to successfully flash back to a non-os no-OTA firmware so I can execute AT commands again. Maybe flashing to custom firmware is a one way trip?

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- Wed Sep 28, 2016 11:47 am #55820 Writing up a post always seems to resolve my issues somehow, without anyone even responding! I saw in one of the great many ESP8266 firmware releases something that said "too large for 4mb". So I went back and tried the AT firmware based off of version 1.4 and it works! So these 4mb chips aren't supported by the newer firmware.

As a follow up, I'm now trying to flash AT firmware onto an 8mb esp8266-01. So far no luck. I don't get the solid light but garbage comes across in the serial monitor. These chips came with 1.5.4 firmware so I'll eventually figure out how to flash that.

Update #2: I still haven't gotten any newer firmware flashed, but I was able to flash the 1.4 firmware and it works.