Show HN: Icepi Zero – The FPGA Raspberry Pi Zero Equivalent
52 comments
·May 28, 2025jwrallie
If I understood correctly, the ECP5 FPGA can be designed for with open source tooling [0][1], which makes this even more awesome.
OP, if you are planning to commercialize these, try to confirm compatibility, that will definitely make it more attractive!
[0] https://hackernoon.com/getting-started-using-open-source-fpg...
Cyao
I am indeed using fully open source tooling! Check out the makefiles in the firmware directory :)
kam
The examples in the repo are using the open-source yosys + nextpnr tooling.
MegaDeKay
I checked out his post on Reddit [0]. OP (cyao12) wrote a CPU in Verilog at the age of 13 and is now only 16. Mind. Blown.
cyao12: I'm going to try and put the old cpu I made in verilog when I was 13 on it! The sdram is okay, the traces are short enough that the distance difference doesn't matter :D
Collez_boi: You made a freaking CPU in Verilog when you were 13?! That's crazy.
cyao12: Yeaaah, but tbh the design wasnt really good lol. Im 16 now so Im quite happy about my progress
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utopcell
The FPGA used seems to be quite popular in the hobbyist community. If you don't care about the form factor, there exist relatively cheap high-volume ECP5-based boards that have been repurposed to be general FPGA dev boards [1].
[1] https://www.amazon.com/Price-Colorlight-5A-75B-Screen-Receiv...
robinsonb5
The only downside of those is that the SDRAM chip is wired with its DQM pins tied low, which means you can't do byte writes to SDRAM - you have to write a full word at a time. That makes it much harder to port existing cores to the ColorLight boards.
NoOn3
Another project like FPGA in "Pi Zero" format was fleaFPGA_Ohm (http://fleasystems.com/fleaFPGA_Ohm.html).
duskwuff
Yep - unfortunately, that never appears to have been available for purchase outside the Indiegogo campaign.
utopcell
This looks like a great project, a fun toy to play with.
However, stating that:
> I've always wanted a low-cost portable FPGA with video output to make my own CPU, but there isn't any on the market.
is definitely not true: one can buy Sipeed's Tang Nano boards for $25+ on Amazon (or less if one needs fewer than 20k LUTs).
Cyao
Oh that's nice, how come I never saw those!
robinsonb5
The Gowin chips are quite interesting - they have RAM built in to the FPGA itself. It's SDRAM in the case of the Tang Nano 20k. It's a 32-bit wide RAM, but unfortunately only 8 megabytes, which is a bit limiting. The FPGA's clocking is a bit limited, too. (For that reason, there's an extra clock generator on the Tang Nano 20k.)
utopcell
You stepped up to share something, we shared something back. :-)
ost-ing
Fpga is kind of like the final frontier in my embedded trajectory, haven’t made the leap yet mainly because microcontrollers or fixed arch cpus are fast enough for most consumer tech. I’d love to give it a shot one day though
nebula8804
What is this FPGA capable of? Can any of the cores of the MISter cores be ported over to this?
robinsonb5
I recently got a build of the Minimig Amiga core running on IceSugarPro (which has the same FPGA and same size SDRAM) - only the ECS chipset (no AGA) but I did get RTG graphics working at 1280x720x16bit. It uses PS/2 rather than USB for keyboard and mouse, but apart from that it would be trivial to port to this new board.
whitehexagon
I found this one so far:
https://github.com/emard/ulx3s_c64
Exciting to have an alternative to de10-nano, especially seeing the price doubled? since I got mine.
Amazing project anyway, and brings back dreams of building some arcade cabinates. Icepi Zero looks perfect for the job! I hope they arrive in the EU one day.
Cyao
it probably can - I see that uls3x already has a few ported over cores, and they will be able to run on this fpga with little modifs
kaoD
What's the approximate cost of materials?
deivid
Can you sell these assembled? Using Tang nano for learning right now, but the tooling and docs situation is not great
Graziano_M
The icebreaker is great and easy to get up and running, plus it has pmod headers which makes it easy to add add-ons.
duskwuff
Yep, and I love it. That's a much smaller (and lower pin count) FPGA than this ECP5, though.
robinsonb5
IceSugarPro (with its breakout board) is quite a nice board if you want something pre-assembled. Same FPGA as this new board (so also supported by the Open Source toolchain), same size SDRAM, HDMI out but PMODs for everything else.
I really like the look of this new board, though - I definitely want to get my hands on one. (I also have a Tang Nano 20K but don't like it all that much.)
jedbrooke
can the HDMI be configured as input?
this looks super cool! it’s inspiring me to finally dust of the NeTV2 board I have. but alas time for hobbies has been in short supply for a while
Cyao
it can! no reason why it wouldnt be
aappleby
Take my money already. :D
mysterydip
Impressive! Looks well thought out. FPGA programming is something I've wanted to get into, this might be my entry point. Great work!
I've been hacking away lately, and I'm now proud to show off my newest project - The Icepi Zero!
In case you don't know what an FPGA is, this phrase summarizes it perfectly: "FPGAs work like this. You don't tell them what to do, you tell them what to BE." You don't program them, but you rewrite the circuits they contain!
So I've made a PCB that carries an ECP5 FPGA, and has a raspberry pi zero footprint. It also has a few improvements! Notably the 2 USB b ports are replaced with 3 USB C ports, and it has multiple LEDs.
This board can output HDMI, read from a uSD, use a SDRAM and much more. I'm very proud the product of multiple weeks of work. (Thanks for the pcb reviews on r/PrintedCircuitBoard )
(All the sources on github under an open source license :D)
PS. See some more pics on reddit https://www.reddit.com/r/FPGA/comments/1kwxvk8/ive_made_my_f...