Pre-production 'fun' and more..

A project log for 'Flea Ohm' FPGA Project

My attempt at making an FPGA experimenters board in a popular form factor :)

Valentin AngelovskiValentin Angelovski 07/01/2017 at 12:292 Comments

Hello again,

A fair lot has happened since our last blog post. Unfortunately that included getting a chest infection put me out for at least a fortnight - but I am feeling much better now :)

First attempt at assembly of pre-production Ohm PCBs:

So I received my Pre-production Ohm boards and had some fun assembling them. I say 'fun' because it seems I may need to tweak my soldering process for these pre-production ready PCBs. Following is a picture of a slightly overdone pre-production Ohm board (notice the slight charring along the top of the PCB near the main GPIO header):

Luckily for me, this board wasn't a total writeoff (only one DRAM failed during functional testing), which is great because I've got a 45KLUT FPGA installed on it.. :) Illness forced me to 'take a break' from any further project work before I could attempt to make any more -

Hopefully I will be more successful in my 2nd attempt tomorrow :)

My first Ohm 'hat' (yay! :-)

Also, I managed to assemble my retro game 'hat' for Flea Ohm! Not 100% tested yet, but at least the PS/2 and Game ports worked fine with the overcooked Ohm board in the previous pic ;) There are even more interesting hats to create (and even the retro gaming hat can of course be improved on..) but hey everything has to start somewhere heh :-D

I did not have any ESP-12E modules on hand, so I slapped on a plain old ESP-12 instead. I will need the 12E variant if I want SDIO, but I may instead move on to an ESP-32 version as I previously wanted to - time permitting of course.

Re-rise of the pi zero variant??

Another thing that happened before I got sick: Now all of you may remember this project of mine started out as a pi zero sized board? Well I have definitely not forgotten about it! About a month ago I had decided I was going to have another go at making a zero-sized fpga board - this time using the physically larger FPGA package as used in my current Ohm:

(To be continued.. :-)


mike01 wrote 07/06/2017 at 09:02 point

Hi, Valentin. 

I have been following your designs since the first FleaFPGA (which I own), and this new board is superb! The new size of the FPGA (45k LUTS) is great!!!

I love that retro game "hat", since my main interest is retrocomputing. I would like to see many systems working on that board (Amiga, Atari ST, PC XT, ...).

Personally, I like the current form factor more than the "Pi Zero", but it would also be interesting if both designs were available.

I will be tuned to the following steps of this project.


  Are you sure? yes | no

Valentin Angelovski wrote 07/19/2017 at 16:20 point

Hi Mike,

Thanks for your comments and also your kind words. I have since managed to resurrect my earlier (and smaller) form factor and so I may well find myself in a situation where both boards could be made available. Watch this space! :-)  

Cheers, Valentin

PS: I hope your FleaFPGA board has served you well.

  Are you sure? yes | no