Macro assign_resources::assign_resources

macro_rules! assign_resources {
    {
        $(
            $(#[$outer:meta])*
            $group_name:ident : $group_struct:ident {
                $(
                    $(#[$inner:meta])*
                    $resource_name:ident : $resource_field:ident $(=$resource_alias:ident)?),*
                $(,)?
            }
            $(,)?
        )+
    } => { ... };
}

Extract the specified fields from the Peripherals struct into several named structs which can be passed to other tasks to provide them with all their resources, including pins, peripherals, DMA channels, etc.

The peripherals module must be in scope when resource_assigs!{} is called, and it defines a new macro split_resources!() which uses the Peripherals struct and returns a new struct with a field for each of the structs named in resource_assigs!{}.

Defines new structs containing the specified structs from the peripherals module, a top-level struct called AssignedResources that contains an instance of each of these new structs, and a macro that creates the top-level struct and populates it with fields from a Peripherals instance.

Example

use assign_resources::assign_resources;
use embassy_stm32::peripherals;
 
assign_resources! {
    usb: UsbResources {
        dp: PA12,
        dm: PA11,
        usb: USB,
    }
    leds: LedResources {
        r: PA2,
        g: PA3,
        b: PA4,
        tim2: TIM2,
    }
}

#[embassy_executor::task]
async fn usb_task(r: UsbResources) {
    // use r.dp, r.dm, r.usb
}

#[embassy_executor::task]
async fn led_task(r: LedResources) {
    // use r.r, r.g, r.b, r.tim2
}

#[embassy_executor::main]
async fn main(spawner: embassy_executor::Spawner) {
    let p = embassy_stm32::init(Default::default());
    let r = split_resources!(p);
    spawner.spawn(usb_task(r.usb)).unwrap();
    spawner.spawn(led_task(r.leds)).unwrap();

    // can still use p.PA0, p.PA1, etc
}