An Augmented reality brainfuck interpreter

A few weeks ago I spent some time teaching my 8 year old nephew how to code using hedy 1. I assumed that the challenging part would be communicating concepts like variables, memory and scope but instead our biggest hurdle was typing.

I thought every child born in the 2000s could type at 100 words per minute from birth. They spend countless hours on x-boxes and iphones but never touch a keyboard? Huh. I needed to re-access my plan.

My nephew told me he uses voice control for everything, "why would I type when I can ask siri". All this to say that we didn't make a lot of progress on our first session, but it was typing not programming that was slowing us down.

It left me wondering if there were other ways to program computers that weren't so keyboard centric.

I devised an experiment to make a coffee table programming card game. One which you could write a program with physical cards and have your phone interpret and run it.

I guess conceptually it's pretty similar to punch cards except it gives instant feedback and IDE features like time travel debugging and memory visualisation using augmented reality.

I chose brainfuck 2 as the language to implement. As it's name suggests, it's really hard to write, but it's extreme minimalism made it easy to implement an interpreter and print the 8 symbol cards, so that made it a pretty good fit.

brainfucks symbol cards on a table

For context this is a hello world program in brainfuck:


BrainfuckAR works by printing out brainfuck's 8 symbols. You can then compose your program by scanning each symbol with your phone.

screenshot of scanning

Once you are ready you can step through the program and watch the memory cells mutate on your phone screen and the eventually see the output of your program.

screenshot of memory

It's been fun to build but hard to use.

The augmented reality works well enough, but the cards are cumbersome to use and because brainfuck is such a verbose language it can take ages program anything. Ironically using a keyboard is way easier. I think if the target language was simpler or if it was more gamified it would be more interesting.

If you'd like to try brainfuck-AR or check out the code you can find it on github

  • 1: Hedy is a gradual language with an web IDE that guides you through levels, as you progress the language becomes more and more complex until you are eventually writing python.
  • 2: Brainfuck is an esoteric programming language notable for its extreme minimalism, the language consists of only eight simple commands, a data pointer and an instruction pointer.