Merge #1004

1004: Fix internal channels for adc v2 r=lulf a=chemicstry

Internal channel reading was broken on adc_v2, because `Adc::read()` requires gpio pin trait, which was not implemented by `VrefInt`, `Temperature`, `Vbat`. The required configuration bits `tsvrefe`, `vbate` were not enabled either. This PR makes it a bit closer to how adc_v4 works.

While at it, I also changed adc_v2 to use `RccPeripheral` instead of permanently enabling all ADCs.

Co-authored-by: chemicstry <chemicstry@gmail.com>

examples/stm32f4/src/bin/adc.rs

@@ -2,9 +2,10 @@
 #![no_main]
 #![feature(type_alias_impl_trait)]
 
+use cortex_m::prelude::_embedded_hal_blocking_delay_DelayUs;
 use defmt::*;
 use embassy_executor::Spawner;
-use embassy_stm32::adc::Adc;
+use embassy_stm32::adc::{Adc, Temperature, VrefInt};
 use embassy_time::{Delay, Duration, Timer};
 use {defmt_rtt as _, panic_probe as _};
 
@@ -13,12 +14,30 @@ async fn main(_spawner: Spawner) {
     let p = embassy_stm32::init(Default::default());
     info!("Hello World!");
 
-    let mut adc = Adc::new(p.ADC1, &mut Delay);
+    let mut delay = Delay;
+    let mut adc = Adc::new(p.ADC1, &mut delay);
     let mut pin = p.PC1;
 
+    let mut vrefint = adc.enable_vrefint();
+    let mut temp = adc.enable_temperature();
+
+    // Startup delay can be combined to the maximum of either
+    delay.delay_us(Temperature::start_time_us().max(VrefInt::start_time_us()));
+
     loop {
+        // Read pin
         let v = adc.read(&mut pin);
-        info!("--> {} - {} mV", v, adc.to_millivolts(v));
+        info!("PC1: {} ({} mV)", v, adc.to_millivolts(v));
+
+        // Read internal temperature
+        let v = adc.read_internal(&mut temp);
+        let celcius = Temperature::to_celcius(adc.to_millivolts(v));
+        info!("Internal temp: {} ({} C)", v, celcius);
+
+        // Read internal voltage reference
+        let v = adc.read_internal(&mut vrefint);
+        info!("VrefInt: {} ({} mV)", v, adc.to_millivolts(v));
+
         Timer::after(Duration::from_millis(100)).await;
     }
 }