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By lazarvgd
#75816 Hi there,

A few days ago I have flashed my 4 boards(nodemcu/lolin) with the MicroPython firmware. Everything passed without any issues until I have started accessing the boards with picocom(alternative to screen software)...

The first to boards responded without problems, I was able to get python console and execute python commands, also I was able to upload scripts and make them bootable(to be called main.py). But problem occurred with third and fourth boards. I was able to flash them without problems, but when I tried to access them in order to get python console, the picocom was stuck, no response form the board.

To be sure that I have not made any mistake or bricked the boards, I have uploaded arduino blink sketch, and got working board with blinking LED.

Again, I have flashed both boards according to the adafruit guide. Flashing passed without issues, I have tried to access with Picocom and got the same problem from the beginning of this post.

Does anybody know what is wrong with the boards or am I doing something wrong?

Please help me to solve this issue...

Thanks :)
User avatar
By QuickFix
#75817 Take a board that doesn't work and connect it to USB, set the baud rate of your terminal (picocom) to 74880 baud (yes, it's an odd rate, though not a typo) and restart the board.

Copy the boot messages that you see and post them here; they might shed some light on the problem. :idea:
User avatar
By lazarvgd
#75823 Hey, thank you for your reply, here is the output:
The first board:
Code: Select allets Jan  8 2013,rst cause:2, boot mode:(3,6)

load 0x40100000, len 31100, room 16
tail 12
chksum 0xef
ho 0 tail 12 room 4
load 0x00000000, len 0, room 12
tail 0
chksum 0xef
load 0x00000000, len 0, room 4
tail 0
chksum 0xef
csum 0xef
csum err
ets_main.c

The second board:

Code: Select allets Jan  8 2013,rst cause:2, boot mode:(3,7)

load 0x40100000, len 31100, room 16
tail 12
chksum 0xef
ho 0 tail 12 room 4
load 0x33333333, len 858993459, room 12



QuickFix wrote:Take a board that doesn't work and connect it to USB, set the baud rate of your terminal (picocom) to 74880 baud (yes, it's an odd rate, though not a typo) and restart the board.

Copy the boot messages that you see and post them here; they might shed some light on the problem. :idea:
User avatar
By QuickFix
#75827 To start with: I know nothing about microPython and there are members here that are far more experienced than I am. :idea:

Once an ESP can boot properly anything should run as it should.
Your output it giving a checksum error on the first board
Code: Select allcsum err
and the second board stops while loading the "room 12" section.

What happens if you flash the boards at a lower baud rate?