Bacca70 QMK "Error reading line 1"

Hi all,

I just got around to building my Bacca70 I bought in '21. The build went great, and the PCBs were good (I bought two, and both tested successfully).

When I went to flash it with Via firmware, I kept getting “Error reading line 1”:

Both PCBs are completely bricked because the “Erasing flash” part succeeded.

Not sure where to go from here. I’ve built over 30 keyboards and have never run into this before. Any ideas?

Do you have a .hex file to flash? I have a memory of flashing my atmega32u4 based boards with .hex firmware files

The official Via firmware and firmware generated using QMK uses the .bin extension. In the temporary .build folder, there’s a .hex file, but it doesn’t work for flashing.

Oh, I misunderstood the drop down saying atmega32u4. Bacca70 is using stm32 so .bin is correct

Edit: Looking again QMK Toolbox seems to try to flash it as an atmega32u4 which is wrong

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If that’s the case, it should be an easy fix. Just change the QMK toolbox drop-down on the top right to the correct chip :+1:

Oops, that’s wrong. Apparently you don’t need to do anything for ARM chips on Mac

This should be true for any stm32 chip, right?

I’m confused (please forgive my stupidity!). When I plug it in in DFU mode, it shows as ATmega32U4:

Atmel DFU device disconnected: ATMEL ATm32U4DFU (03EB:2FF4:0000)
Atmel DFU device connected: ATMEL ATm32U4DFU (03EB:2FF4:0000)

If bacca70 is stm32, how would one flash it using that?

Could it be that they switched the MCU they used for the PCB because of shortage? Do you have a picture of the MCU on your pcb? I couldn’t find any online for Bacca70

Maybe so. The MCU is definitely an ATMEL mega32U4. I also can’t find any information on it. No build guide or even the creator. :frowning:

Are you able to flash it with the default QMK firmware? Wouldn’t be as convenient as VIA but at least it wouldn’t be bricked.

It’s available through the QMK configurator

I noticed the board should have a bootmagic reset if you hold escape while plugging it in.

BlindAssassin111 designed the PCB. He’s fairly well known, and someone around here may have his contact info.

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No, sadly I can’t even flash the original firmware on it. It can go into DFU mode, even erase the existing firmware, but errors when reading any firmware for it.

I reached out to him on Geekhack a few months ago and got a response within a day or two. Might be worth a try.

I worked with him to troubleshoot a PCB a few years back, the AT101 replacement board. Got it all sorted out through discord. I can’t find him there now though. I think group buy anger trolls probably forced him to either get off of discord or change his username. :smiling_face_with_tear:

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I contacted him via Discord, and he sent me a working firmware file!

It turns out the original PCB was ARM, and then the silicon shortage happened, so they switched to the 32u4 before the group buy. The incorrect existing firmware was merged into QMK and Via, and no one caught the issue until I did. Haha.


Thank you for the help everyone!



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