Add example for using ADC1 and 2 together

Complete implementation of clock selection

Author: richardeoin

examples/adc.rs

@@ -1,3 +1,8 @@
+//! Example of reading a voltage with ADC1
+//!
+//! For an example of using ADC3, see examples/temperature.rs
+//! For an example of using ADC1 and ADC2 together, see examples/adc12.rs
+
 #![no_main]
 #![no_std]
 
@@ -50,25 +55,32 @@ fn main() -> ! {
     let mut delay = Delay::new(cp.SYST, ccdr.clocks);
 
     // Setup ADC
-    let mut adc3 =
-        adc::Adc::adc3(dp.ADC3, &mut delay, ccdr.peripheral.ADC3, &ccdr.clocks)
-            .enable();
-    adc3.set_resolution(adc::Resolution::SIXTEENBIT);
+    let mut adc1 = adc::Adc::adc1(
+        dp.ADC1,
+        &mut delay,
+        ccdr.peripheral.ADC12,
+        &ccdr.clocks,
+    )
+    .enable();
+    adc1.set_resolution(adc::Resolution::SIXTEENBIT);
+
+    // We can't use ADC2 here because ccdr.peripheral.ADC12 has been
+    // consumed. See examples/adc12.rs
 
     // Setup GPIOC
     let gpioc = dp.GPIOC.split(ccdr.peripheral.GPIOC);
 
     // Configure pc0 as an analog input
-    let mut channel = gpioc.pc0.into_analog();
+    let mut channel = gpioc.pc0.into_analog(); // ANALOG IN 10
 
     loop {
-        let data: u32 = adc3.read(&mut channel).unwrap();
+        let data: u32 = adc1.read(&mut channel).unwrap();
         // voltage = reading * (vref/resolution)
         println!(
             log,
             "ADC reading: {}, voltage for nucleo: {}",
             data,
-            data as f32 * (3.3 / adc3.max_sample() as f32)
+            data as f32 * (3.3 / adc1.max_sample() as f32)
         );
     }
 }

examples/adc12.rs

@@ -0,0 +1,75 @@
+//! Example of using ADC1 and ADC2 together
+//!
+//! For an example of using ADC3, see examples/temperature.rs
+//! For an example of using ADC1 alone, see examples/adc.rs
+
+#![deny(unsafe_code)]
+#![no_main]
+#![no_std]
+
+extern crate panic_itm;
+
+use cortex_m;
+use cortex_m_rt::entry;
+
+use stm32h7xx_hal::{adc, delay::Delay, pac, prelude::*};
+
+use cortex_m_log::println;
+use cortex_m_log::{
+    destination::Itm, printer::itm::InterruptSync as InterruptSyncItm,
+};
+
+#[entry]
+fn main() -> ! {
+    let cp = cortex_m::Peripherals::take().unwrap();
+    let dp = pac::Peripherals::take().unwrap();
+    let mut log = InterruptSyncItm::new(Itm::new(cp.ITM));
+
+    // Constrain and Freeze power
+    println!(log, "Setup PWR...                  ");
+    let pwr = dp.PWR.constrain();
+    let vos = pwr.freeze();
+
+    // Constrain and Freeze clock
+    println!(log, "Setup RCC...                  ");
+    let rcc = dp.RCC.constrain();
+
+    let ccdr = rcc
+        .sys_ck(100.mhz())
+        .pll2_p_ck(4.mhz()) // Default adc_ker_ck_input
+        .freeze(vos, &dp.SYSCFG);
+
+    println!(log, "");
+    println!(log, "stm32h7xx-hal example - ADC1 and ADC2");
+    println!(log, "");
+
+    let mut delay = Delay::new(cp.SYST, ccdr.clocks);
+
+    // Setup ADC1 and ADC2
+    let (adc1, adc2) = adc::adc12(
+        dp.ADC1,
+        dp.ADC2,
+        &mut delay,
+        ccdr.peripheral.ADC12,
+        &ccdr.clocks,
+    );
+
+    let mut adc1 = adc1.enable();
+    adc1.set_resolution(adc::Resolution::SIXTEENBIT);
+
+    let mut adc2 = adc2.enable();
+    adc2.set_resolution(adc::Resolution::SIXTEENBIT);
+
+    // Setup GPIOC
+    // NOTE: PC2 and PC3 are only pinned out on TFBGA packages!!
+    let gpioc = dp.GPIOC.split(ccdr.peripheral.GPIOC);
+    let mut channel_pc2 = gpioc.pc2.into_analog(); // AIN 12
+    let mut channel_pc3 = gpioc.pc3.into_analog(); // AIN 13
+
+    loop {
+        let data_pc2: u32 = adc1.read(&mut channel_pc2).unwrap();
+        let data_pc3: u32 = adc2.read(&mut channel_pc3).unwrap();
+        // voltage = reading * (vref/resolution)
+        println!(log, "ADC readings: {} {}", data_pc2, data_pc3);
+    }
+}

examples/temperature.rs

@@ -1,3 +1,8 @@
+//! Example for using ADC3 to read the internal temperature sensor
+//!
+//! For an example of using ADC1, see examples/adc.rs
+//! For an example of using ADC1 and ADC2 together, see examples/adc12.rs
+
 #![deny(unsafe_code)]
 #![no_main]
 #![no_std]
@@ -37,7 +42,7 @@ fn main() -> ! {
 
     let ccdr = rcc
         .sys_ck(100.mhz())
-        .per_ck(4.mhz())
+        .pll2_p_ck(4.mhz()) // Default adc_ker_ck_input
         .freeze(vos, &dp.SYSCFG);
 
     println!(log, "");

src/adc.rs

@@ -1,7 +1,7 @@
 //! Analog to Digital Converter (ADC)
 //!
 //! ADC1 and ADC2 share a reset line. To initialise both of them, use the
-//! `adc12` method.
+//! [`adc12`](adc12) method.
 
 use crate::hal::adc::{Channel, OneShot};
 use crate::hal::blocking::delay::DelayUs;
@@ -296,6 +296,8 @@ pub struct StoredConfig(AdcSampleTime, Resolution, AdcLshift);
 fn check_clock(prec: &impl AdcClkSelGetter, clocks: &CoreClocks) -> Hertz {
     // Select Kernel Clock
     let adc_clock = match prec.get_kernel_clk_mux() {
+        Val(rec::AdcClkSel::PLL2_P) => clocks.pll2_p_ck(),
+        Val(rec::AdcClkSel::PLL3_R) => clocks.pll3_r_ck(),
         Val(rec::AdcClkSel::PER) => clocks.per_ck(),
         _ => unreachable!(),
     }