MicroPython Forum (Archive)

Hi there,

I have problem with flash memory on lolin board. Few days ago I was getting files from the board without problem using ampy application, but today I am unable to list, put, remove files from board. So I decided to flash the chip and write firmware again with esp tool.
The result was ok, I have got message about erasing and message about flashing the chip, but when I tried to put new file to the board with command , terminal on my machine left in state of executing the command. No errors, no new line so I can enter any other command.

My question is how can i troubleshot this problem? Is it related to the board or I have missed some flags since not all flash memories are the same?

Thanks

The Lolin boards have a history of hardware failing.

I think they have been using some bad clones of the CP2104 Uart to USB that is causing the problem.

see one users videos on fixing the problem https://www.youtube.com/watch?v=OrQWos9VcgM

I had one LOLIN32 where the CP2104 was poorly soldered, and a LOLIN32 pro which crashes with the Pycom or micropython.org firmware, not immediately, but after a while. It works with the loboris firmware. Replacing the flash chip did not help. A second LOLIN32 pro runs fine.

I have a few boards, all are performing well, except this one.

It is strange that I can flash and erase it, but cannot put files...

It is controlled by different software: Erase and flash is done by the espressif bootloader, while file upload is done by the MicroPython firmware.

I built a number of boards of my own design myself. I built the first 10 using cheap CP2104 of aliexpress and about half of them failed. I built about another 25 boards using CP2104 brought from Digikey and all work correctly.

I had the same problem with the pca9685pw chip I was buying off Aliexpress, many of them would fail within a short time.

Here is something that might help... with the Ampy software I always include the -d1 option. The -d1 option adds a one-second delay before ampy tries to use the raw REPL mode of operation. Using the option fixed the Ampy program hangs that I was seeing.

Mike Teachman wrote: ↑

Mon Dec 03, 2018 11:55 pm

Here is something that might help... with the Ampy software I always include the -d1 option. The -d1 option adds a one-second delay before ampy tries to use the raw REPL mode of operation. Using the option fixed the Ampy program hangs that I was seeing.

Thanks, I will try your solution and update you with the outcome.