fix pid.rs test, exclude dfu from test

src/dfu.rs

@@ -14,6 +14,7 @@ pub unsafe fn set_dfu_trigger() {
 /// Called by reset handler in lib.rs immediately after reset.
 /// This function should not be called outside of reset handler as 
 /// bootloader expects MCU to be in reset state when called.
+#[cfg(target_arch = "arm")]
 #[pre_init]
 unsafe fn __pre_init() {
     if _dfu_msg == DFU_TRIG_MSG {

src/pid.rs

@@ -172,11 +172,12 @@ mod test {
         let mut values = [DEFAULT; DELAY];
         let mut t = 0;
         let mut total_t = 0;
+        let mut output: f64 = 0.0;
         let target = (TARGET - ERROR)..=(TARGET + ERROR);
         while !values.iter().all(|value| target.contains(value)) && total_t < CYCLE_LIMIT {
             let next_t = (t + 1) % DELAY;
             // Feed the oldest temperature
-            let output = pid.update(values[next_t], Time::new::<second>(1.0), values[next_t]);
+            output = pid.update(values[next_t], Time::new::<second>(1.0), ElectricCurrent::new::<ampere>(output));
             // Overwrite oldest with previous temperature - output
             values[next_t] = values[t] + output - (values[t] - DEFAULT) * LOSS;
             t = next_t;