tec_u_meas: subtract vref offset

full duty pwm is at vref already

src/channels.rs

@@ -318,22 +318,21 @@ impl Channels {
 
     pub fn get_max_v(&mut self, channel: usize) -> (ElectricPotential, ElectricPotential) {
         let vref = self.channel_state(channel).vref;
+        let max = 4.0 * vref;
         let duty = self.get_pwm(channel, PwmPin::MaxV);
-        (duty * 4.0 * vref, 4.0 * vref)
+        (duty * max, max)
     }
 
     pub fn get_max_i_pos(&mut self, channel: usize) -> (ElectricCurrent, ElectricCurrent) {
-        let vref = self.channel_state(channel).vref;
-        let scale = vref / ElectricPotential::new::<volt>(3.0) / ElectricCurrent::new::<ampere>(1.0);
+        let max = ElectricCurrent::new::<ampere>(3.0);
         let duty = self.get_pwm(channel, PwmPin::MaxIPos);
-        (duty / scale, 1.0 / scale)
+        (duty * max, max)
     }
 
     pub fn get_max_i_neg(&mut self, channel: usize) -> (ElectricCurrent, ElectricCurrent) {
-        let vref = self.channel_state(channel).vref;
-        let scale = vref / ElectricPotential::new::<volt>(3.0) / ElectricCurrent::new::<ampere>(1.0);
+        let max = ElectricCurrent::new::<ampere>(3.0);
         let duty = self.get_pwm(channel, PwmPin::MaxINeg);
-        (duty / scale, 1.0 / scale)
+        (duty * max, max)
     }
 
     fn set_pwm(&mut self, channel: usize, pin: PwmPin, duty: f64) -> f64 {
@@ -365,24 +364,23 @@ impl Channels {
 
     pub fn set_max_v(&mut self, channel: usize, max_v: ElectricPotential) -> (ElectricPotential, ElectricPotential) {
         let vref = self.channel_state(channel).vref;
-        let duty = (max_v / 4.0 / vref).get::<ratio>();
+        let max = 4.0 * vref;
+        let duty = (max_v / max).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxV, duty);
-        (duty * 4.0 * vref, 4.0 * vref)
+        (duty * max, max)
     }
 
     pub fn set_max_i_pos(&mut self, channel: usize, max_i_pos: ElectricCurrent) -> (ElectricCurrent, ElectricCurrent) {
-        let vref = self.channel_state(channel).vref;
-        let scale = vref / ElectricPotential::new::<volt>(3.0) / ElectricCurrent::new::<ampere>(1.0);
-        let duty = (max_i_pos * scale).get::<ratio>();
+        let max = ElectricCurrent::new::<ampere>(3.0);
+        let duty = (max_i_pos / max).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxIPos, duty);
-        (duty / scale, 1.0 / scale)
+        (duty * max, max)
     }
 
     pub fn set_max_i_neg(&mut self, channel: usize, max_i_neg: ElectricCurrent) -> (ElectricCurrent, ElectricCurrent) {
-        let vref = self.channel_state(channel).vref;
-        let scale = vref / ElectricPotential::new::<volt>(3.0) / ElectricCurrent::new::<ampere>(1.0);
-        let duty = (max_i_neg * scale).get::<ratio>();
+        let max = ElectricCurrent::new::<ampere>(3.0);
+        let duty = (max_i_neg / max).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxINeg, duty);
-        (duty / scale, 1.0 / scale)
+        (duty * max, max)
     }
 }

src/main.rs

@@ -187,7 +187,7 @@ fn main() -> ! {
                                                 vref.into_format_args(volt, Abbreviation), dac_feedback.into_format_args(volt, Abbreviation),
                                                 itec.into_format_args(volt, Abbreviation), tec_i.into_format_args(ampere, Abbreviation),
                                                 tec_u_meas.into_format_args(volt, Abbreviation),
-                                                (tec_u_meas / tec_i).into_format_args(ohm, Abbreviation),
+                                                ((tec_u_meas - vref) / tec_i).into_format_args(ohm, Abbreviation),
                                             );
                                         } else {
                                             let _ = writeln!(socket, "channel {}: no adc input", channel);
@@ -269,7 +269,7 @@ fn main() -> ! {
                                         match (state.get_adc(), state.get_sens(), state.get_temperature()) {
                                             (Some(adc), Some(sens), Some(temp)) => {
                                                 let _ = writeln!(
-                                                    socket, "- adc={:.6} r={:.0} temp{}={:.3}K",
+                                                    socket, "- adc={:.6} r={:.0} temp{}={:.3}",
                                                     adc.into_format_args(volt, Abbreviation),
                                                     sens.into_format_args(ohm, Abbreviation),
                                                     channel,