temperature needs to be calibrated against Vref+

RM0351 pg580 says to scale the read value by (Vref+ / 3.0)

Author: Crzyrndm

src/adc.rs

@@ -277,9 +277,11 @@ impl ADC {
     }
 
     /// Convert a raw sample from the `Temperature` to deg C
-    pub fn to_degrees_centigrade(sample: u16) -> f32 {
-        (130.0 - 30.0) / (VtempCal130::get().read() as f32 - VtempCal30::get().read() as f32)
-            * (sample as f32 - VtempCal30::get().read() as f32)
+    pub fn to_degrees_centigrade(&self, sample: u16) -> f32 {
+        let sample = (u32::from(sample) * self.calibrated_vdda) / VDDA_CALIB_MV;
+        (VtempCal130::TEMP_DEGREES - VtempCal30::TEMP_DEGREES) as f32
+            / (VtempCal130::get().read() - VtempCal30::get().read()) as f32
+            * (sample - u32::from(VtempCal30::get().read())) as f32
             + 30.0
     }
 

src/signature.rs

@@ -93,25 +93,32 @@ impl VrefCal {
 }
 
 /// A temperature reading taken at 30°C stored at the factory
+/// aka TS_CAL1
 #[derive(Debug)]
 #[repr(C)]
 pub struct VtempCal30(u16);
 define_ptr_type!(VtempCal30, 0x1FFF_75A8);
 
 impl VtempCal30 {
+    /// TS_CAL1_TEMP
+    pub const TEMP_DEGREES: u16 = 30;
     /// Read calibration value
     pub fn read(&self) -> u16 {
         self.0
     }
 }
 
 /// A temperature reading taken at 130°C stored at the factory
+/// aka TS_CAL2
 #[derive(Debug)]
 #[repr(C)]
 pub struct VtempCal130(u16);
 define_ptr_type!(VtempCal130, 0x1FFF_75CA);
 
 impl VtempCal130 {
+    /// TS_CAL2_TEMP
+    /// TODO: this is 110 for L47x, 130 for L43x
+    pub const TEMP_DEGREES: u16 = 130;
     /// Read calibration value
     pub fn read(&self) -> u16 {
         self.0