New Convoy 7135x8 driver - mcu not programmable!

Flashlight Modding and DIY Parts
1

I intended to test the otc-less design we discussed in the attiny firmware thread and a ramping firmware with the new red Convoy 8x7135 driver (whith actually is 105D design):
https://de.aliexpress.com/store/product/7135x3-7135x4-7135x6-7135x8-with-new-firmware/330416_32734523412.html

- but I was not able to program the mcu. I do this programming every day with different programmers and drivers, so I don’t believe it’s a fault on my side.

I assume SPI programming has been disabled when loading Biscotti into the mcu, but it might also be a faulty connection on the driver board. Since I only have 1 of this drivers currently I can’t check with others.
Has anybody been successful in re-programming this driver?

Edit:
Btw, I had the same problem with the newer batch of BLF X6 FET+1 drivers, they also weren’t programmable. Here the reason clearly was wrong fuse setting (SPI disabled), some other forum member verified this problem and was able to program the mcu with high voltage programming, which overrides disabled SPI. I guess I have to build a high voltage programmer soon.

2

Ok, now I know why in-circuit programming doesn’t work with this driver:
Pin 5 - which is required for SPI - is connected to ground. :person_facepalming:

So you will not be able to re-program the mcu on this driver without PCB modification.
I cut through the trace from mcu pin5 to gnd, now I’m able to program the mcu.

3

Yes, i read that too in the ‘new Convoy C8, clearly better’ thread.

4

I have encountered this problem too when trying to flash a modified biscotti to the driver. So glad that I found your tread from google :D.

Thanks!