From 7a64ce91d4378f9d7a822a3da1a11b0e5138c9b3 Mon Sep 17 00:00:00 2001
From: zdmx <hi@zdmx.me>
Date: Fri, 27 Sep 2024 23:24:55 +0200
Subject: [PATCH] succd: check currentmost pirani values for safety lock

---
 succbone/succd/process.go | 37 +++++++++++++------------------------
 1 file changed, 13 insertions(+), 24 deletions(-)

diff --git a/succbone/succd/process.go b/succbone/succd/process.go
index f63748b..643d053 100644
--- a/succbone/succd/process.go
+++ b/succbone/succd/process.go
@@ -123,15 +123,7 @@ func (d *daemon) processOnce(_ context.Context) error {
 	d.aboveRough.process(float64(mbar))
 	d.aboveHigh.process(float64(mbar))
 
-  klog.Infof("rate of change: %f", d.piraniRateOfChange())
-
-  // max rate of 1.0 in 500 ms because ringbuffer holds 5 values
-  if d.piraniRateOfChange() > 2.0 {
-    if !d.failsafe {
-      d.failsafe = true
-			klog.Errorf("Pressure changed too fast; entering failsafe mode")
-    }
-  } else if mbar < 4e-6 {
+  if d.piraniWireBreakDetection() {
 		// Unrealistic result, Pirani probe probably disconnected. Failsafe mode.
 		if !d.failsafe {
 			d.failsafe = true
@@ -197,23 +189,20 @@ func (d *daemon) processOnce(_ context.Context) error {
 	return nil
 }
 
-func (d *daemon) piraniRateOfChange() float32 {
-  max := d.adcPiraniVolts[0]
-  min := d.adcPiraniVolts[0]
-  for _, val := range d.adcPiraniVolts {
-    if val < min {
-      min = val
-    }
-    if val > max {
-      max = val
-    }
+func (d *daemon) piraniWireBreakDetection() bool {
+  if len(d.adcPiraniVolts) < 3 {
+    return true
   }
-  max_bar := math.Pow(10.0, float64(max)-8.5);
-  max_mbar := float32(max_bar * 1000.0)
-  min_bar := math.Pow(10.0, float64(min)-8.5);
-  min_mbar := float32(min_bar * 1000.0)
+  volts := float32(0.0)
+  for _, v := range d.adcPiraniVolts[len(d.adcPiraniVolts)-3:] {
+    volts += v
+  }
+  volts /= 3.0
 
-  return max_mbar - min_mbar
+  bar := math.Pow(10.0, float64(volts)-8.5)
+  mbar := float32(bar * 1000.0)
+
+  return mbar < 4e-6
 }
 
 // pirani returns the Pirani gauge voltage and pressure.