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Comment by sneak | Hacker News Reader

Slightly offtopic, but perhaps someone here can shed some light:

What are the best hobbyist use cases for FPGAs? Most of the stuff I do can be accomplished with microcontrollers or embedded systems like RPi, I imagine FPGAs become more important when you're doing things like DSP or hard realtime requirements, which don't come up super often in hobbyist projects.

I'd like to do more hobby projects involving FPGAs so what sorts of things might low cost FPGAs be useful for in that realm?

I'm thinking of building a clock that integrates a local atomic oscillator, outputs from an embedded system running ntpd, and drives a local VFD as a sort of orientation project.

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The single most popular hobby use case may be the Mister project for near perfect, super low latency retro gaming emulation.

Another common use case is real time video stream manipulation. There is a demo by Bunnie Huang who uses an fpga to intercept, decode, then reencode HDMI video streams (including microsecond timing manipulation of one of the data lines) in order to do video overlays on the video (for things like captions).

In general the main use cases are really for things that require lots of parallel and/or low latency processing.

this for me, just bought the kit needed to help out on the PSX core https://github.com/RobertPeip/PlayStation_MiSTer

Another quick idea is a cnc positioning stage that uses optical interfrerometry to measure distance moved. Really anything involving fast fringe counting in an interference pattern. It might be something like a new fringe for every micron of movement, so tracking something moving 1 m/s will require fringe counting at about 1 MHz, and the ADC sampling rate will need to be several times this in practice because errors are cumulative.

I'm using an ice40 FPGA to make a camera. It reads an image from an image sensor, writes it to an SDRAM, and then writes the SDRAM content to an SD card. Doing all that with a regular CPU would require lots of specialized peripherals (especially since the data rate is 1.2 Gbps -- 12 bits per pixel @ 100 MHz). An FPGA can handle all the requirements quite well.

If you are motivated by learning rather than practical usage, FPGAs are a great way to learn more about how things like CPUs or peripherals can be designed. It is also a way to understand how to evolve hardware and software at the same time.

Two examples that I have been loosely involved with; * Google's CFU playground which is all about profiling and adding small number of new OpCodes to build an accelerator for a specific ML model (http://cfu-playground.rtfd.io/). * The Fomu workshop (https://workshop.fomu.im) which walks though treating an FPGA like an embedded MCU where you can then modify the MCU!

Project F (https://projectf.io/posts/fpga-graphics/) has a lot of cool examples with visually interesting output.

A quick example might be a device which outputs a channel of audio per pin using super fast pwm

After seeing some of the FPGA uses in research papers, I have no idea what the best uses are but I feel like we might on the edge of a revolution if enough people can get moderately powerful FPGAs on a $5 board.

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