From 2e9c1d14677be6efaf66f4b962b5e2a908dccec5 Mon Sep 17 00:00:00 2001
From: atse <atse@m-labs.hk>
Date: Fri, 26 Jan 2024 13:04:20 +0800
Subject: [PATCH] Average out reads instead of waiting for stability

Reading until the error falls into a certain tolerance might cause
bootlooping as the ADC values just might never settle. Average it out
instead.
---
 src/channels.rs | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/src/channels.rs b/src/channels.rs
index e33a0b6..c62cab2 100644
--- a/src/channels.rs
+++ b/src/channels.rs
@@ -169,17 +169,6 @@ impl<'a> Channels<'a> {
         }
     }
 
-    pub fn read_dac_feedback_until_stable(&mut self, channel: usize, tolerance: ElectricPotential) -> ElectricPotential {
-        let mut prev = self.read_dac_feedback(channel);
-        loop {
-            let current = self.read_dac_feedback(channel);
-            if (current - prev).abs() < tolerance {
-                return current;
-            }
-            prev = current;
-        }
-    }
-
     pub fn read_itec(&mut self, channel: usize) -> ElectricPotential {
         match channel {
             0 => {
@@ -265,11 +254,14 @@ impl<'a> Channels<'a> {
     /// thermostat. 
     pub fn calibrate_dac_value(&mut self, channel: usize) {
         let samples = 50;
-        let mut target_voltage = ElectricPotential::new::<volt>(0.0);
-        for _ in 0..samples {
-            target_voltage += self.read_vref(channel);
-        }
-        target_voltage /= samples as f64;
+        let target_voltage = {
+            let mut target_voltage = ElectricPotential::new::<volt>(0.0);
+            for _ in 0..samples {
+                target_voltage += self.read_vref(channel);
+            }
+            target_voltage /= samples as f64;
+            target_voltage
+        };
         let mut start_value = 1;
         let mut best_error = ElectricPotential::new::<volt>(100.0);
 
@@ -287,7 +279,14 @@ impl<'a> Channels<'a> {
                     _ => unreachable!(),
                 }
 
-                let dac_feedback = self.read_dac_feedback_until_stable(channel, ElectricPotential::new::<volt>(0.001));
+                let dac_feedback = {
+                    let mut dac_feedback = ElectricPotential::new::<volt>(0.0);
+                    for _ in 0..samples {
+                        dac_feedback += self.read_dac_feedback(channel);
+                    }
+                    dac_feedback /= samples as f64;
+                    dac_feedback
+                };
                 let error = target_voltage - dac_feedback;
                 if error < ElectricPotential::new::<volt>(0.0) {
                     break;