Doppler 1.0



Say hello to our latest creation – the doppler!
A Cortex M4F Microcontroller + FPGA development board. It comes in the same tiny form factor similar to a Teensy and is open source.

We are very excited about FPGA’s but getting started with them is daunting especially because of the ecosystem of proprietary toolchains and expensive hardware. The doppler takes away most of these pains by providing all the tooling to get you up and running.

There are two chips on the board a SAMD51 ARM Microcontroller and an ICE40 FPGA. The Microcontroller is easily programmable with, for example, the beginner-friendly Arduino environment. It also needs to be used to upload the configuration as a bitstream to the FPGA. This guide goes in detail on how to set up both development environments for the SAMD51 and the ICE40.

For now all documentation is in the github repository:

Feel free to make issues there.You can ask questions & show what you are working on here in the forum.


Mine arrived this week. Will be putting it through its paces.

Haven’t done played with Arduino much in a little while. Did get a Teensy Audio board (and a Teensy 3.6) but have yet to use that setup. Will be following instructions and experimenting, hoping to get some insight into FPGA. For instance, using that to modulate a lowpass filter in as smooth a way as possible. It’d be nice to do this from breath control. Got a tiny air pressure sensor that I might try to use for this.


Has anybody else had problems with the build instructions?

I try to build icestorm with docker but it fails out during the yosys installation, as it can’t find eigen3. Yosys works fine on my local machine using homebrew.

I rarely use docker other than to occasionally test other people’s images, so there could well be something wrong with my config.

Many Thanks.


Dockerfile need an update like this …


ah, nice one, cheers


Let me know if it works for you. We updated the docker stuff like two weeks ago. And the issue with “eigen3” should have been resolved with that.


Yeah, all good thanks.
I pulled the repo when I ordered the board and lost track of time, so, I thought I was up to date.