cheap fpga recommendation

[CodeInHardware]

Could someone recommend a cheap FPGA? Preferably under 10$, if it doesn't exist then under 20$.

[brucehoult]

https://mou.sr/3KY8q7P

[CodeInHardware]

thanks, but i would like a devboard, i'm a begineer.
ps. Also something working with Icestudio, and having easy to understand begineer friendly documentation.

[ftg]

I think the currently cheapest FPGA devkits with usable documentation are Sipeed's Tang Nano series.
The Sipeed Lichee Tang Nano 4K gpes for under 20eur on Aliexpress and Sipeed Lichee Tang Nano 1k can be sometimes found for under 15eur on ali.

Gowin GW1N-series also seems to have some support in Yosys/nextpnr, so you are not limited to the vendor provided tools.
https://github.com/YosysHQ/apicula

Other low cost options include various FPGA based LED panel controllers and the more random aliexpress specials with older Altera or Xilinx parts.
There might be also some cheap Lattice iCE40 based boards out there, but the chips have had very hit & miss availability.

[Nominal Animal]

Olimex iCE40HX8K-EVB or iCE40HX1K-EVB.  They're Open Source Hardware, with schematics and KiCad design files available.

[brucehoult]

thanks, but i would like a devboard, i'm a begineer.

You asked for an FPGA, not a board. Perhaps be more clear in future?

https://www.aliexpress.us/item/1005006046955854.html

[CodeInHardware]

thanks for all the replies, the last one looks good, can it handle vga or composite with it's 1152 lut's?
also does it support icestudio?

[Postal2]

Search EBAZ4205, must be about 15$.
https://aliexpress.com/item/1005005919123170.html

[up8051]

Też polecam moduły z serii Tang Nano z układami FPFA firmy Gowin Semiconductors.
Do generacji sygnałów VGA wystarczy kilkadziesiąt LUTs ale pamiętaj o potrzebnej pamięci RAM na bufor obrazu.
Jaką rozdzielczość i głębię koloru chcesz uzyskać.

I also recommend Tang Nano series modules with FPFA chips from Gowin Semiconductors.
Several dozen LUTs are enough to generate VGA signals, but remember about the necessary RAM for the image buffer.
What resolution and color depth do you want to achieve?

[CodeInHardware]

dziękuje, rozdzielczość 640x480 3 bity koloru. Możesz dać linka na allegro?

[up8051]

At this resolution, it will be necessary to use PSRAM memory (external in Tang Nano, built-in in Tang Nano 4K and 9K).
The photos show an example of using TangNano in the DMD2VGA converter module (flipper displays).
VGA works with RGB656 color depth.

[zapta]

Could someone recommend a cheap FPGA? Preferably under 10$, if it doesn't exist then under 20$.

I was in same situation recently, picked the Upduino, and am very happy with it. It fits in a solderless breadboard and works with open source tools such as APIO and IceStudio.

https://tinyvision.ai/products/upduino-v3-1

Tang (a Chinese vendor) has similar boards that work, I think, with tools they provide.

Here is a list of boards that are supported by the open source tool chain

```
apio boards --list
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Board (FPGA, Arch, Type, Size, Pack)
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
• Alchitry-Cu  (FPGA:iCE40-HX8K-CB132, ice40, hx, 8k, cb132)
• Butterstick-r10-2g-85k  (FPGA:ECP5-LFE5UM5G-85F-CABGA381, ecp5, um5g-85k, 85k, CABGA381)
• Butterstick-r10-2g-85k_(FT2232H)  (FPGA:ECP5-LFE5UM5G-85F-CABGA381, ecp5, um5g-85k, 85k, CABGA381)
• Butterstick-r10-2g-85k_(FT232H)  (FPGA:ECP5-LFE5UM5G-85F-CABGA381, ecp5, um5g-85k, 85k, CABGA381)
• Cat-board  (FPGA:iCE40-HX8K-CT256, ice40, hx, 8k, ct256)
• ColorLight-5A-75B-V61  (FPGA:ECP5-LFE5U-25F-CABGA381, ecp5, 25k, 25k, CABGA381)
• ColorLight-5A-75B-V7  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• ColorLight-5A-75B-V8  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• ColorLight-5A-75E-V6  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• ColorLight-5A-75E-V71_(FT2232H)  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• ColorLight-5A-75E-V71_(FT232H)  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• ColorLight-5A-75E-V71_(USB-Blaster)  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• ColorLight-i5-v7.0_(FT2232H)  (FPGA:ECP5-LFE5U-25F-CABGA381, ecp5, 25k, 25k, CABGA381)
• ColorLight-i5-v7.0_(FT232H)  (FPGA:ECP5-LFE5U-25F-CABGA381, ecp5, 25k, 25k, CABGA381)
• ColorLight-i5-v7.0_(USB-Blaster)  (FPGA:ECP5-LFE5U-25F-CABGA381, ecp5, 25k, 25k, CABGA381)
• ColorLight-i9-v7.2_(FT2232H)  (FPGA:ECP5-LFE5U-45F-CABGA381, ecp5, 45k, 45k, CABGA381)
• ColorLight-i9-v7.2_(FT232H)  (FPGA:ECP5-LFE5U-45F-CABGA381, ecp5, 45k, 45k, CABGA381)
• ColorLight-i9-v7.2_(USB-Blaster)  (FPGA:ECP5-LFE5U-45F-CABGA381, ecp5, 45k, 45k, CABGA381)
• ECP5-Evaluation-Board  (FPGA:ECP5-LFE5UM5G-85F-CABGA381, ecp5, um5g-85k, 85k, CABGA381)
• ECP5-Mini-12  (FPGA:ECP5-LFE5U-12F-CABGA256, ecp5, 12k, 12k, CABGA256)
• ECP5-Mini-25  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• FleaFPGA-Ohm_(FT2232H)  (FPGA:ECP5-LFE5U-25F-CABGA381, ecp5, 25k, 25k, CABGA381)
• FleaFPGA-Ohm_(FT232H)  (FPGA:ECP5-LFE5U-25F-CABGA381, ecp5, 25k, 25k, CABGA381)
• FleaFPGA-Ohm_(USB-Blaster)  (FPGA:ECP5-LFE5U-25F-CABGA381, ecp5, 25k, 25k, CABGA381)
• OK-iCE40Pro  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• ThetaMachines-ETH4K  (FPGA:iCE40-HX4K-TQ144, ice40, hx, 8k, tq144:4k)
• TinyFPGA-B2  (FPGA:iCE40-LP8K-CM81, ice40, lp, 8k, cm81)
• TinyFPGA-BX  (FPGA:iCE40-LP8K-CM81, ice40, lp, 8k, cm81)
• TinyFPGA-EX-rev1  (FPGA:ECP5-LFE5U-85F-CSFBGA285, ecp5, 85k, 85k, CSFBGA285)
• TinyFPGA-EX-rev2  (FPGA:ECP5-LFE5UM5G-85F-CSFBGA285, ecp5, um5g-85k, 85k, CSFBGA285)
• alhambra-ii  (FPGA:iCE40-HX4K-TQ144, ice40, hx, 8k, tq144:4k)
• arice1  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• blackice  (FPGA:iCE40-HX4K-TQ144, ice40, hx, 8k, tq144:4k)
• blackice-ii  (FPGA:iCE40-HX4K-TQ144, ice40, hx, 8k, tq144:4k)
• blackice-mx  (FPGA:iCE40-HX4K-TQ144, ice40, hx, 8k, tq144:4k)
• edu-ciaa-fpga  (FPGA:iCE40-HX4K-TQ144, ice40, hx, 8k, tq144:4k)
• fomu  (FPGA:iCE40-UP5K-UWG30, ice40, up, 5k, uwg30)
• fpga101  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• go-board  (FPGA:iCE40-HX1K-VQ100, ice40, hx, 1k, vq100)
• iCE40-HX1K-EVB  (FPGA:iCE40-HX1K-VQ100, ice40, hx, 1k, vq100)
• iCE40-HX8K  (FPGA:iCE40-HX8K-CT256, ice40, hx, 8k, ct256)
• iCE40-HX8K-EVB  (FPGA:iCE40-HX8K-CT256, ice40, hx, 8k, ct256)
• iCE40-UL1K-Breakout  (FPGA:iCE40-UL1K-CM36A, ice40, ul, 1k, cm36a)
• iCE40-UP5K  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• iCEBreaker  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• iCEBreaker-bitsy0  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• iCEBreaker-bitsy1  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• iCESugar-Pro_(FT2232H)  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• iCESugar-Pro_(FT232H)  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• iCESugar-Pro_(USB-Blaster)  (FPGA:ECP5-LFE5U-25F-CABGA256, ecp5, 25k, 25k, CABGA256)
• iCESugar-nano  (FPGA:iCE40-LP1K-CM36, ice40, lp, 1k, cm36)
• iCESugar_1_5  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• iceWerx  (FPGA:iCE40-HX8K-CB132, ice40, hx, 8k, cb132)
• iceblink40-hx1k  (FPGA:iCE40-HX1K-VQ100, ice40, hx, 1k, vq100)
• icefun  (FPGA:iCE40-HX8K-CB132, ice40, hx, 8k, cb132)
• icestick  (FPGA:iCE40-HX1K-TQ144, ice40, hx, 1k, tq144)
• icezum  (FPGA:iCE40-HX1K-TQ144, ice40, hx, 1k, tq144)
• icoboard  (FPGA:iCE40-HX8K-CT256, ice40, hx, 8k, ct256)
• kefir  (FPGA:iCE40-HX4K-TQ144, ice40, hx, 8k, tq144:4k)
• orangecrab-r02-25f  (FPGA:ECP5-LFE5U-25F-CSFBGA285, ecp5, 25k, 25k, CSFBGA285)
• orangecrab-r02-85f  (FPGA:ECP5-LFE5U-85F-CSFBGA285, ecp5, 85k, 85k, CSFBGA285)
• pico-ice  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• ulx3s-12f  (FPGA:ECP5-LFE5U-12F-CABGA381, ecp5, 12k, 12k, CABGA381)
• ulx3s-25f  (FPGA:ECP5-LFE5U-25F-CABGA381, ecp5, 25k, 25k, CABGA381)
• ulx3s-45f  (FPGA:ECP5-LFE5U-45F-CABGA381, ecp5, 45k, 45k, CABGA381)
• ulx3s-85f  (FPGA:ECP5-LFE5U-85F-CABGA381, ecp5, 85k, 85k, CABGA381)
• upduino  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• upduino2  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• upduino21  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• upduino3  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• upduino31  (FPGA:iCE40-UP5K-SG48, ice40, up, 5k, sg48)
• versa  (FPGA:ECP5-LFE5UM-45F-CABGA381, ecp5, um-45k, 45k, CABGA381)
```

[Rainwater]

The tang nano 9k has an hdmi port and a lot of demo code to help promote sales. Its the one im learning on. $20 last time i checked. I splurged and got the 8.5in 1080 oled touch screen display with it. Total was about 70 bucks.
Im not sure what constitutes fast, but i've gotten things to run at 210MHz. Their toolchain is not as nice as the other manufacturers, but its better than the open-source options. Giving timing reports and a technology viewer and thank god, error messages. Iverilog will sometimes just say.. and i quote "I give up", but the gowin toolchain will spit out an error message describing the error and what line its on.
Its been enjoyable so far.
They dont seam to support retiming yet, so ive gotten to write a lot of fractal recursion functions to help build lut trees decoratedwith registers.
In short, using code with 1 logic level (dff > 4bit lut > dff) you can expect around 4.5ns of propagation time. Or about 200mhz FMax.
You get lots of memory options, distributed, block, ddr.
9000ish lut
6400 registers
Fun stuff.

[Nominal Animal]

iCE40HX1K-EVB + iCE40-IO costs 26€ (+ VAT?) + shipping, but has VGA + PS/2 + IRDA, 64kbytes embedded RAM, 512kbytes SRAM (10ns), and 1280 logic cells.

iCE40HX8K-EVB + iCE40-IO costs 40€ (+ VAT?) + shipping, but has VGA + PS/2 + IRDA, 128kbytes embedded RAM, 512kbytes SRAM (10ns), and 7680 logic cells.

The iCE40-IO uses 9 pins for 9-bit RGB (512 colors).  For 640x480, that needs 338kbytes for the framebuffer.  You could do for example 4 bits per pixel (one bit each for RGB, and one bit to select whether set bits correspond to 50% or 100%), getting the venerable DOS EGA/VGA 16-color palette, in which case 640x480 needs a 76800-byte (640×480×4 = 1,228,800 bit) framebuffer.  A 16-entry look-up table with 9 bits per entry would give you a selectable palette, though.

Sipeed Tang Nano 4K (Gowin GW1NSR-LV4C FPGA) and Tang Nano 9K (Gowin GW1NR-9 FPGA) have a HDMI connector for video; but note this thread for issues.

I must admit I personally prefer the utterly crisp images I get with purely digital (DVI-D/HDMI/DisplayPort) video.

[SiliconWizard]

Pretty good price for these Olimex boards, especially considering that the price of the Lattice dev boards for their small FPGAs (iCE40, MachXO2/3, ...) used to be pretty low ($20-25) and has skyrocketed in the past few years.

[Nominal Animal]

I particularly like the Olimex boards because they're certified OSHW (BG000132 for iCE40HX8K-EVB, BG000133 for iCE40HX1K-EVB), and that sort of effort deserves a reward.  More practically, as a hobbyist myself, if I want or need, I can start with the existing KiCad board files, and spin my own variant –– although the 100-pin 0.5mm VQFP ('1K) and 256-ball 0.8mm pitch BGA ('8K) are a bit scary!

For example Mouser sells the exact bare FPGA chips right now (2024-06-21) for 6.84€ and 17.48€, respectively (+VAT and shipping), so the Olimex prices for the dev board (and VGA, DAC, ADC accessories) is quite good.

[brucehoult]

I particularly like the Olimex boards

I've never bought any Olimex stuff except a JTAG interface, but I'm impressed by the work they're putting into a $1 RISC-V "PC" (in the same sense as an Apple I or ZX80 is a PC)

https://www.olimex.com/Products/Retro-Computers/RVPC/open-source-hardware

[zapta]

Two more things to consider when selecting a board are the programmer and the PC interface. Some boards have onboard USB programmer (e.g. FT232) and some have also a second USB channel for PC data connectivity (e.g. FT2232).