Pycom W01 boot: UART not working

[formica]

Hi guys,
we are working with a batch of Pycom W01 (serial n° 4817M2) that seems not working anyway. We are not able to communicate through serial at the boot (P2 to GND). We was able to program the same module in the past (serial n° 2217M2). No communication at all. We can't read flash_id or chip_id using esptool as well.

Any idea?

[robert-hh]

@Gijs I know this reference board. But the poster should better tell, what is used and how it is used.

[Gijs]

@robert-hh There is the OEM reference board: https://docs.pycom.io/datasheets/oem/universal_reference/ that they could be using. It transforms a W01 into a Wipy in a hardware-sense.

[robert-hh]

@formica The W01 is the OEM variant of the Wipy3. How do you connect it to the expansion board/USB. Do you have your own boards? Or a test adapter?

[techykermit]

@formica Are all jumpers in place on the expansion board? They are located in the upper left corner and some of them are very important for transmitting data...

[formica]

The usb cable is a data cable. I'm programming them through the expansion board that is recognised perfectly.
The first batch of module (serial n° 4817M2) is working while the second isn't working at all.
No UART.

[formica]

This post is deleted!

[Gijs]

First, make sure you are using a usb cable that has the communication leads connected (not just a charging cable) and see if the module is recognised by the computer (either through lsusb or in the device manager). You mention you are able to use a different module, making me believe its not the USB cable but perhaps something different. Are you able to communicate to the device (at all) through the Pymakr plugin, without putting it in firmware upgrade mode?
Has the module ever worked for you or not at all from the beginning?
Let me know!
Gijs