ESP8266 Community Forum

I have been working with a NodeMCU 12E module using a custom firmware from the NodeMCU builder site and as I am on windows using the NodeMCU flasher GUI without problems. I want to port my project to the Wemos D1 module for some of the units I will be building and cannot get any firmware to properly boot after flashing. I have read up on the module and seen about having to add the bootloader to the first part of memory and whilst in theory the GUI flasher should work it doesn't so I have been trying the esptool.py for the job. In all cases the flash completes but the system will not boot, simply spewing the csum error at 74880 baud on the console.
For example:

Yeilds:

at the command prompt and

at the ESPlorer.

I have tried various combinations of baud rate, write speed, dio / qio and flash sizes and all give the same result. In the case above the firmware.bin is my custom firmware which works on the esp8266 but I have also tried various demo firmwares from around the web.

Finally, if I try and run the esptool.py against one of my working NodeMCU units it times out with a no packet header error.

Can anyone point me in the correct direction here?

I had the same problem with an ESP-01. Trying to do it with dout instead of dio or qio solved it.

My current parameters are: -fm dout -ff 40m -fs 1MB. When flashing try always to specify everything according to your device to avoid getting default parameters from esptool.

Hope this solves your problem! I did the same as you, tried all combinations with qio/dio but never used dout until I saw that it's the default for some boards.

WOW! thank you!
I thought I had tried all the options for DOUT etc. but that seems to have fixed it. Had actually given up thinking I had a dodgy clone device and have ordered a few different ones on Ebay.