Reply To: OSSC Pro firmware v0.78

[marqs]

I had a chance to look into 2 cheap USB blaster clones today which both looked like the ones in previous link (blue stripe in the middle). Internally they were not same, though: the older one had STM32 MCU while the newer had CH552G. Custom firmware was available for the latter, but its PCB was slighly different to this post and lacked marked test points/holes. Shorting D+ to 3.3V before plugging in did not start the bootloader either, but reading more about the chip revealed that it can be alternatively available by shorting pin 3 to GND before plugging. This seemed to start the bootloader for 10sec during which I was able to initiate fw flashing procedure via ch55xtool. After this the programmer was properly recognized in Linux and capable of firmware flashing.

There’s a few caveats as you can see. There is no guarantee that buying one will get you the right model (I guess <$3 ones are best bets). On the other hand any of the clones might work as-is, at least in Windows. Depending on how familiar you are with this kind of tinkering, updating fw on a compatible USB Blaster clone can be quite easy or very frustrating. If that sounds too much work, we could send a pre-programmed one that is checked to work in your preferred environment (Win10/11 or Linux).