About

Follow-along repository for embedded Rust tutorial video series The Rusty Bits on Youtube.

This is an embedded Rust project that utilizes the BBC Microbit microcontroller board. The microbit is a microcontroller board with a 5x5 LED-matrix, sensors, a microfone, two buttons and a speaker. It uses an nRF52833 microprocessor.

1 Debug message

It simply runs a loop that outputs a debug message using rtt-target (Real-Time Transfer protocol) which should appear in your terminal.

2 Blinky-LED

a manually setup

Configure GPIO pins manually according to nRF52833 product specification document using unsafe rust and pointers.

b using nrf52833-pac the PAC (peripheral access crate)

Configure GPIOs using the peripherals provided by the PAC.

c using nrf52833-hal the HAL (hardware abstraction layer)

Configure GPIOs using the hardware abstraction layer which in turn accesses the pac.

d using microbit-v2 - the BSP (board support package) for the microbit

Using the board support packaget for the microbit we can use everything even more ergonomically.

e use the microbit-v2's display struct

Displaying 2 different 5x5 1bit images on the microbit.

3 little 2d turing machine

A turing machine with a 2-dimensional (periodic) memory field (a 5x5 array) instead of the usual 1-dimensional ribbon. In it's default version it has 3 states and 2 symbols (On/Off). After 128 steps of iteration the machine resets and its configuration is mutated by randomizing one element in the instructions table (see illustration). The turing machine has a current state and reads a symbol at the current head position. For every combination of current state and currently read symbol the machine will 1. write a new symbol at the current head's position, move its head and change into a new state. In the 2 dimensional case the head's move directions are UP, LEFT, DOWN, RIGHT. One possible machine configuration is the following:

(current state, read symbol) -> (new state, new symbol, head direction) (A, 0) -> ( A , 0, U ) (B, 1) -> ( C , 1, D ) (C, 0) -> ( A , 0, R ) (A, 1) -> ( B , 0, L ) (B, 0) -> ( C , 1, L ) (C, 1) -> ( B , 1, D )

For 3 states, 2 symbols and 4 head directions there are 3 * 2 * 3 * 2 * 4 = 36 * 4 = 144 possible turing machines.

Setup

• install the cargo plugin cargo-embed using $cargo install cargo-embed (may take a while)

Running the program:

Connect your microbit and run the command $ cargo embed.

Links

• (microbit schematic)[https://github.com/microbit-foundation/microbit-v2-hardware/blob/main/V2.21/MicroBit_V2.2.1_nRF52820%20schematic.PDF]