EBAZ4205 VS gowin_flipflop_drainer

Depending on what you're doing, the EBAZ4205 boards are a very inexpensive way to get a XC7Z010 board. They aren't super friendly, but there is some IO broken out to the headers, and you can find them pretty easily with the SD card slot soldered on. Perhaps not the best intro board, but maybe worth a look all the same.

I have one of those board too, I don't remember any important traces being at that corner other than power planes, so if you measure no shirts between power and ground you should be good. To be safe, you can view the pcb file from https://github.com/xjtuecho/EBAZ4205/tree/master/HW/ebaz4205/altium in the online altium viewer and check for any traces in that area that may have been damaged

Looking forward for the BT miner controller board sold as repurposed FPGA boards.

You should also be aware of the github dump about it, if you're not already. I got mine in a week or two ago after seeing the last post, and haven't had a chance to play with them :( Soon...

Good stuff. I just started wiring it to a 5V buck converter based on the github page here https://github.com/xjtuecho/EBAZ4205 but now I'm going to up the volts before I add an sdcard.

You can find a repro of this effect at https://github.com/juj/gowin_flipflop_drainer/ that you can play with yourself. See also https://www.reddit.com/r/FPGA/comments/101pagf/sipeed_tang_nano_4k_9k_gowin_fpgas_become/

Right now the latest struggle is that we are blocked on this issue: https://github.com/juj/gowin_flipflop_drainer which I am not sure if it will turn out to be a killer for our project or not. Hoping for the best.

Overall I have enjoyed developing on these boards, although I should state that there is a bit of an outstanding trouble with these boards that has blocked my design from proceeding (check out https://github.com/juj/gowin_flipflop_drainer for details). It is still unclear if that only affects video application, general SERDES applications, or what.

If someone has a Twitter account, could you ask Sipeed whether the new Tang Nano 20K will be immune to this problem https://github.com/juj/gowin_flipflop_drainer ?

If this was a power issue, given that the "nonsense adders" in the test case in https://github.com/juj/gowin_flipflop_drainer are operating at a high clock speed that is desynchronized from the video subsystem, then I would expect that there would have been noise present in the power delivery more or less "constantly", and at random times with respect to the video signals.

You can find the test case repository at https://github.com/juj/gowin_flipflop_drainer

I concur with Sipeed. I really like them as well, they are lean and easy to get started, although right now I am struggling with a hardware instability problem on those boards :/ ( https://github.com/juj/gowin_flipflop_drainer )