SavvyCal's Derrick Reimer on Elixir

If you ever listened to The Art of Product podcast you may have picked up that one of the hosts, Derrick Reimer, was actually using Elixir for his venture SavvyCal.

We had the pleasure of bringing in Derrick to get down in the weeds of tehnology for a change and talk about the tech he uses, rather than just all that fancy product talk.

Podcast: BEAM Radio, episode 75

The two sides of Nerves

The Nerves project is a framework in the Elixir ecosystem for building IoT devices and working with hardware. The Nerves project is a framework in the Embedded Linux ecosystem for building IoT devices and developing software.

Nerves is a set of opinionated choices on how to structure an embedded Linux firmware, software for specific hardware, project.

There are fundamentally two groups of people who use Nerves.

The first group are Enthusiasts|Hobbyists that want to do things with hardware. They typically use Raspberry Pis, they rarely customize systems, they pretty much never bring up a new system for a new board. They write only Elixir code in their projects.

The second group are professionals in embedded Linux. This is a different world.

They may use Raspberry Pis but are much more likely to be doing any number of other boards. The BeagleBone Black has been a steady one for a long time but SmartRent has done a lot with Allwinner processors as well as others, Redwire Labs maintain systems for a Microchip board and are giving love and attention to a newer series of TI boards. In many cases the boards are dominated by which chip they run so that TI board is a AM625 Sitara processor which can then be found on the BeaglePlay. That dev board system for the professional TI variant will probably need some adaptation to run the BeaglePlay but the bigger parts should be taken care of. There are also System-on-Modules (SOMs) that are similarly feasible to adapt, much like a Raspberry Pi Compute Module. This is all Linux work. It requires recompiling a lot of kernels to work out and debugging skills that bridge hardware and software.

These Nerves users always customize systems.

They might mostly write Elixir code if they are fortunate enough but they will exercise most layers of Nerves. From Buildroot, to fwup, partitioning, overlays and on into the Elixir side of things.

This is not a binary. I was absolutely a hobbyist and enthusiast and I'm moving ever more into the embedded part. I have a lot to learn on that path which suits me fine. And someone fairly new to Nerves could feasibly ship an RPi or BBB-based V1 product at low volume. Especially with Pi-based builds like what SeeedStudio does with ReTerminal and other ReThings. A lot of work you don't need to do. But business efficiencies will have you trend towards more purpose-specific boards, custom designs that scale well and suddenly you are deep in BOMs, parts, board bring-up, supply-chains, data sheets, electronics design and Call for Pricing.

If you like learning things I truly recommend starting to claw your way across this gradient. If CRUD feels dull, you can instead be frustrated about intimate parts of Linux which is probably novel and definitely full of variety.

For Nerves this is a tricky thing. I love that Frank has continuously put effort into maintaining it as an on-ramp for hobbyists and tinkerers to get to work with the hardware in a more practical and also more professional way. If you do basic stuff with Nerves you are still using Buildroot and a tight Embedded Linux package. It is not a toy. It is production kit with a friendly face. It is a heck of a needle to thread and I applaud it.

Try Nerves if you haven't. It sure beats trying to maintain a custom setup on top of Raspberry OS.

What have you tried to do with hardware if anything? Do you have a board in a drawer somewhere? Could you please enlist it in my device fleet above? :D You can reach me on the Fediverse where I'm @lawik@fosstodon.org or by responding to this email to lars@underjord.io.

Thank you for reading. I appreciate it.