LO1 OEM struggles to upload data via Pymakr or ampy.

[miro_bli]

Hi all,

I recently created a custom board for my project that contains an OEM LO1 module. I use FTDI FT230R Basic UART to communicate with it. I am able to connect to REPL very reliably, however when I try to upload files I get different errors such as

Failed to write file, trying again...

It works maybe once in 5 times, especially if I turn off and on the UART cable.
I tried couple different firmwares, no difference. Once in a while I also receive

Guru Meditation Error: Core  1 panic'ed (IllegalInstruction)

error. Could this mean there's something wrong with the ESP32 itself?

Is there anything such as a certain pin not being pulled up that could cause that? I have a LoPy with the expansion board to use as a reference but I can't seem to find anything that is out of place on my board.

Above is the circuitry around the LO1 module, hope that helps.

Many thanks,
Miro

[danielm]

In my opinion RESET pin should not be left floating. Try to connect pull-up resistor to 3.3V in 10k-20k range.
Check L01 OEM Baseboard schematic:
https://docs.pycom.io/product-info-datasheets/oem/l01_reference

Edit: Sorry, now I noticed the reset pull-up already being in your schematic. Anyway try to use FTP client for script uploading.