Module tm4c123x_hal::gpio

Expand description

General Purpose Input / Output

This module makes heavy use of types to try and ensure you can’t have a pin in a mode you didn’t expect.

Most pins start in the Tristate state. You can call methods to convert them to inputs, outputs or put them into Alternate Function mode (e.g. to use with a UART).

Some of the modes require extra information, and for that we use the so- called ’Turbo Fishsyntax, which looks likemethod::`.

If the operation is non-atomic, then you need to pass a mut-reference to the port’s control structure. This ensures you can’t change two pins in two threads at the same time. If the operation is fully atomic (using the chip’s bit-banding feature) then this argument is not required.

Here’s an example:

let p = Peripherals::take().unwrap();
let mut sc = p.SYSCTL.constrain();
let mut portb = p.GPIO_PORTB.split(&sc.power_control);
let timer_output_pin = portb.pb0.into_af_push_pull::<gpio::AF7>(&mut portb.control);
let uart_tx_pin = portb.pb1.into_af_open_drain::<gpio::AF1, gpio::PullUp>(&mut portb.control);
let blue_led = portb.pb2.into_push_pull_output();
let button = portb.pb3.into_pull_up_input();