Crate pamoja_hal 

The bus layer for the pamoja SDK.

Every part a node talks to sits on a bus: I2C for the dense breakout sensors, SPI for displays and radios, a GPIO line for a relay or a button, 1-Wire for a waterproof thermometer on a long cable. The drivers in pamoja-sensors and pamoja-actuators are written against traits rather than against a board, and this crate is where those traits come from and where the buses that implement them live:

• i2c, spi, digital, and delay are the embedded-hal 1.0 traits, re-exported so a driver and the code that opens its bus name one thing. Any HAL that implements them drives every pamoja part unchanged: embassy-rp on an RP2040, esp-hal on an ESP32, the Linux backends below on a Raspberry Pi.
• onewire is the bus embedded-hal does not define: the 1-Wire protocol a DS18B20 speaks, bit-banged over any open-drain pin and a delay, with the reset and presence handshake, the ROM commands, and the search that enumerates a bus.
• script plays a part’s side of a conversation: an I2C bus that checks each transfer against a script and answers with the bytes a real part would send, a pin that records what it was driven to, and a delay that records how long it was asked to wait. A driver is tested against the datasheet’s own sequence with nothing plugged in.
• linux (feature linux, Linux only) opens the kernel’s /dev/i2c-*, /dev/spidev*, and GPIO character devices as those same traits, so a gateway reads a sensor with one call and no glue.

Examples

A script stands in for a part that answers a one-byte register read: the chip id a BME280 returns for register 0xD0.

use pamoja_hal::i2c::I2c;
use pamoja_hal::script::{I2cScript, I2cStep};

let mut bus = I2cScript::new([I2cStep::write_read(0x76, [0xD0], [0x60])]);
let mut id = [0u8; 1];
bus.write_read(0x76, &[0xD0], &mut id)?;
assert_eq!(id, [0x60]);
assert!(bus.done());

Re-exports

pub use embedded_hal;

Modules

delay

Delays.

digital

Digital I/O.

i2c

Blocking I2C API.

linux

Linux backends: the kernel’s I2C, SPI, and GPIO character devices as the bus traits.

onewire

The 1-Wire bus: one data line, a pull-up resistor, and strict timing.

script

Scripted buses: a part’s side of the conversation, for tests with nothing plugged in.

spi

Blocking SPI master mode traits.