From eb052133a3e8ff98adfc93e52984e0c1b626b0d0 Mon Sep 17 00:00:00 2001
From: Ken <>
Date: Wed, 30 Oct 2019 15:42:45 -0400
Subject: [PATCH] =?UTF-8?q?Code=20change=20implements=20analogReadFast,=20?=
 =?UTF-8?q?which=20reduces=20the=20read=20time=20of=20an=20anolog=20pin=20?=
 =?UTF-8?q?from=20112=20=C2=B5S=20down=20to=2021=20=C2=B5S.?=
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---
 .../src/Pyr0_Piezo_Sensor_V2.x.x.cpp                      | 4 ++--
 .../AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/pP_function.h | 8 ++++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/Pyr0_Piezo_Sensor_V2.x.x.cpp b/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/Pyr0_Piezo_Sensor_V2.x.x.cpp
index af37f29..26bddca 100644
--- a/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/Pyr0_Piezo_Sensor_V2.x.x.cpp
+++ b/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/Pyr0_Piezo_Sensor_V2.x.x.cpp
@@ -156,8 +156,8 @@ void loop() {
 
     // Check voltage of first and second stages and compare against thresholds
     readVin();
-    VComp = analogRead(VCOMP_SENSE_PIN);
-    VFol = analogRead(V_FOLLOW_PIN);
+    VComp = analogReadFast(VCOMP_SENSE_PIN);
+    VFol = analogReadFast(V_FOLLOW_PIN);
 
     VLast = VOld - Vin;
     if (VLast > Hyst || VLast < -Hyst) {
diff --git a/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/pP_function.h b/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/pP_function.h
index fdf588f..4395428 100644
--- a/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/pP_function.h
+++ b/firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/src/pP_function.h
@@ -12,6 +12,14 @@ void digitalWriteFast(uint8_t pin, uint8_t x) {
   }
 }
 
+int inline analogReadFast(byte ADCpin)
+{ byte ADCSRAoriginal = ADCSRA;
+  ADCSRA = (ADCSRA & B11111000) | 4;
+  int adc = analogRead(ADCpin);
+  ADCSRA = ADCSRAoriginal;
+  return adc;
+}
+
 /*------------------------------------------------*/
 
 void pulse() {