test: tests for temperature without linker error

examples/aes_ecb.rs

@@ -24,7 +24,8 @@ fn main() -> ! {
     let mut rcc = dp.RCC.freeze(Config::hsi16());
     let mut delay = cp.SYST.delay(rcc.clocks);
 
-    compile_error!("The chip does not have an AES unit >:{");
+    // WARN: Make sure your chip has AES
+    panic!("The chip does not have an AES unit >:");
     let aes = hal::aes::AES::new(dp.AES, &mut rcc);
     let mut ecb_stream = aes.enable(<dyn hal::aes::Mode>::ecb_encrypt(), AES_KEY);
     let mut encbuf: [[u8; 16]; 4] = [[0; 16]; 4];

examples/blinky-external.rs

@@ -0,0 +1,46 @@
+#![no_main]
+#![no_std]
+
+use defmt_rtt as _; // global logger
+//
+use panic_probe as _;
+use cortex_m_rt::entry;
+use hal::{pac, prelude::*, rcc::Config};
+
+#[entry]
+fn main() -> ! {
+    let dp = pac::Peripherals::take().unwrap();
+    let cp = cortex_m::Peripherals::take().unwrap();
+
+    let mut rcc = dp.RCC.freeze(Config::hsi16());
+
+    let gpioa = dp.GPIOA.split(&mut rcc);
+    let gpiob = dp.GPIOB.split(&mut rcc);
+
+    let mut builtin_led = gpioa.pa5.into_push_pull_output();
+    let mut led0 = gpiob.pb5.into_push_pull_output(); // D4
+    let mut led1 = gpiob.pb4.into_push_pull_output(); // D5
+
+    let mut delay = cp.SYST.delay(rcc.clocks);
+
+    builtin_led.set_high().unwrap();
+    led0.set_high().unwrap();
+    led1.set_high().unwrap();
+
+    loop {
+        builtin_led.set_high().unwrap();
+        led0.set_low().unwrap();
+        led1.set_low().unwrap();
+        delay.delay_ms(100_u16);
+
+        led0.set_high().unwrap();
+        delay.delay_ms(100_u16);
+
+        builtin_led.set_low().unwrap();
+        delay.delay_ms(100_u16);
+
+        led0.set_low().unwrap();
+        led1.set_high().unwrap();
+        delay.delay_ms(100_u16);
+    }
+}

examples/temperature.rs

@@ -1,49 +1,104 @@
-#![no_main]
+#![cfg_attr(not(test), no_main)]
-#![no_std]
+#![cfg_attr(not(test), no_std)]
 
-use defmt::info;
+#[cfg(not(test))]
-use hal::adc::{Adc, Ready, VTemp};
+extern crate panic_halt;
-use hal::gpio::Analog;
-use hal::gpio::gpiob::PB1;
-use panic_probe as _;
 
-use defmt_rtt as _; // global logger
+use hal::adc::{Adc, Ready, VRef, VTemp};
-
+use hal::calibration::{VtempCal30, VtempCal130};
-use cortex_m_rt::entry;
 use hal::{pac, prelude::*, rcc::Config};
 
-const MAGIC_TEMPERATURE_NUMBER: f32 = 12.412122;
+use defmt::{debug, info};
+use defmt_rtt as _; // global logger
 
-#[entry]
+#[cfg_attr(not(test), cortex_m_rt::entry)] // this is the entrypoint unless testing
 fn main() -> ! {
     let dp = pac::Peripherals::take().unwrap();
     let cp = cortex_m::Peripherals::take().unwrap();
 
     let mut rcc = dp.RCC.freeze(Config::hsi16());
-    let mut adc = dp.ADC.constrain(&mut rcc);
+    let mut adc: Adc<_> = dp.ADC.constrain(&mut rcc);
 
-    let gpiob = dp.GPIOB.split(&mut rcc);
-
-    let mut temp_pin = gpiob.pb1.into_analog();
-
-    // Get the delay provider.
     let mut delay = cp.SYST.delay(rcc.clocks);
 
-    let mut temp;
+    // NOTE: TSEN bit must be enabled for reading the temperature
-    let mut i = 0;
+    VTemp.enable(&mut adc);
+    VRef.enable(&mut adc);
+
+    // reference temperatures from the chips readonly memory
+    // [Source](https://www.st.com/resource/en/datasheet/stm32l053r8.pdf),
+    // Table 6 in Secion 3.13 "Temperature sensor"
+    //
+    // More and better info in the large 1000+ page sheet "Ultra-low-power
+    // STM32L0x3 advanced Arm®-based 32-bit MCUs" (RM0367), 14.9
+    //
+    // This is basically calibration data
+    info!(
+        "reading calibration data... If this is the last thing you hear from me something has gone terribly wrong"
+    );
+    let vref_cal = hal::calibration::VrefintCal::get().read();
+    let tsense_cal1 = (30, VtempCal30::get().read());
+    let tsense_cal2 = (130, VtempCal130::get().read());
+    info!("tsense_cal1: {:?}", (30, tsense_cal1));
+    info!("tsense_cal2: {:?}", (130, tsense_cal2));
+
+    // read a few values into void, maybe this will help get that thing started
+    for _ in 0..20 {
+        let _ = read_temp_mv(&mut adc, 1.0);
+        delay.delay_ms(10_u16);
+    }
+
+    let vref_actual: u16 = adc.read(&mut VRef).unwrap();
+    let vref_factor = vref_cal as f32 / vref_actual as f32;
+    info!(
+        "vref actual={} calibration={} => factor={}",
+        vref_actual, vref_cal, vref_factor
+    );
+
+    delay.delay_ms(10_u16);
+
+    let mut temp_c;
+    let mut temp_mv;
     loop {
-        if i % 10_000 == 0 {
+        temp_mv = read_temp_mv(&mut adc, vref_factor);
-            temp = read_temp_c(&mut temp_pin, &mut adc);
+        temp_c = temp_mv_to_c(temp_mv, tsense_cal1, tsense_cal2);
-            info!("Temperature: {}", temp);
+        info!("Temperature: {:03}mv, {:04}°C", temp_mv, temp_c as i32);
-        }
+        delay.delay_ms(500_u16);
-        // delay.delay_ms(200_u16);
-        i += 1;
     }
 }
 
-fn read_temp_c(pin: &mut PB1<Analog>, adc: &mut Adc<Ready>) -> i16 {
+fn read_temp_mv(adc: &mut Adc<Ready>, vref_factor: f32) -> f32 {
-    let v: f32 = adc
+    let bare: f32 = adc.read(&mut VTemp).expect("could not read with adc");
-        .read(pin /* or maybe VTemp from the adc module? */)
+    bare * vref_factor
-        .expect("could not read with adc");
+}
-    (v / MAGIC_TEMPERATURE_NUMBER) as i16 - 50
+
+// This unholy abomination is from the datasheet and does not actually look so bad if it's written
+// in Math instead of Rust.
+fn temp_mv_to_c(temp: f32, ts_cal_1: (i32, u16), ts_cal_2: (i32, u16)) -> f32 {
+    ((ts_cal_2.0 as f32 - ts_cal_1.0 as f32) / (ts_cal_2.1 as f32 - ts_cal_1.1 as f32))
+        * (temp - ts_cal_1.1 as f32)
+        + ts_cal_1.0 as f32
+}
+
+#[cfg(test)]
+mod tests {
+    // run these tests: cargo test --example=temperature --target=x86_64-unknown-linux-gnu
+    use super::temp_mv_to_c;
+
+    #[test]
+    fn test_mv_to_c() {
+        // values read out from my board as logged
+        // after flashing and running
+        //
+        // First is the temperature for that calibratoin, second is the measured voltage at that
+        // temperature
+        let calibration_data = [(30, 673), (130, 912)];
+        for caldat in calibration_data {
+            let degrees: f32 =
+                temp_mv_to_c(caldat.1 as f32, calibration_data[0], calibration_data[1]);
+            assert_eq!(caldat.0 as f32, degrees);
+            dbg!(caldat);
+            dbg!(degrees);
+        }
+    }
 }

examples/test-on-host.rs

@@ -0,0 +1,59 @@
+//! This example shows how a embedded program can be written that is testable on the host with
+//! libtest.
+//!
+//! The tests can be run with:
+//! ```bash
+//! cargo test --example=test-on-host --target=x86_64-unknown-linux-gnu
+//! ```
+
+#![cfg_attr(not(test), no_main)]
+#![no_std]
+
+#[cfg(not(test))]
+extern crate panic_halt;
+
+use hal::{pac, prelude::*, rcc::Config};
+
+#[cfg_attr(not(test), cortex_m_rt::entry)] // this is the entrypoint unless testing
+fn main() -> ! {
+    let dp = pac::Peripherals::take().unwrap();
+    let cp = cortex_m::Peripherals::take().unwrap();
+
+    // Configure the clock.
+    let mut rcc = dp.RCC.freeze(Config::hsi16());
+
+    // Acquire the GPIOA peripheral. This also enables the clock for GPIOA in
+    // the RCC register.
+    let gpioa = dp.GPIOA.split(&mut rcc);
+
+    // Configure PA5 as output.
+    let mut led = gpioa.pa5.into_push_pull_output();
+
+    // Get the delay provider.
+    let mut delay = cp.SYST.delay(rcc.clocks);
+
+    loop {
+        led.set_high().unwrap();
+        delay.delay_ms(500_u16);
+
+        let important_number = some_function(19);
+        delay.delay_ms(important_number as u16);
+
+        led.set_low().unwrap();
+        delay.delay_ms(500_u16);
+    }
+}
+
+fn some_function(num: i32) -> i32 {
+    num * 2
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::some_function;
+
+    #[test]
+    fn test_it_works() {
+        assert_eq!(some_function(9), 18)
+    }
+}