Fixed "Flappy DAC" bug in rev.2.x.x firmware

- Fixed https://github.com/pyr0ball/pyr0piezo/issues/26
  - Changed adjustment logic to be calculated based on Vcc rather than ADC reference, which was causing issues in the mathematical functions, resulting in negative number outputs
 - Migrated to internal vRef, fixed https://github.com/pyr0ball/pyr0piezo/issues/23
 - Eliminated floats, fixing https://github.com/pyr0ball/pyr0piezo/issues/31
  - This required addition of long, however
 - Fixed https://github.com/pyr0ball/pyr0piezo/issues/20

firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/Pyr0_Piezo_Sensor_v2.x.x.ino

@@ -61,21 +61,21 @@ int GAIN_FACTOR = 2;           // Gain adjustment factor. 0=3x, 1=3.5x, 2=4.33x,
 #define InitCount 6             // Number of times to blink the LED on start
 int LOOP_DUR = 50;        // duration of time between ADC checks and other loop functions
 int TRG_DUR = 20;             // duration of the Z-axis pulse sent, in ms
-#define senseThrs 1.85
+#define senseThrs 1450
-#define compThrs 2.54
+#define compThrs 2850
-
+int dAdjFac = 1;		        // adjustment divider. Higher number will cause the DAC output to adjust more slowly.
 int Hyst = 20;                 // Hysteresis value for ADC measurements
-#define Vin 5                   // input reference voltage
 
 /*------------------------------------------------------------*/
 
 // Debug output toggle. Uncomment to enable
 #define DEBUG true
+//#define VERBOSE true
 
 // Headers, variables, and functions
 #include "pP_pins.h"
 #include "pP_volatile.h"
-#include "pP_functions.h"
+#include "pP_function.h"
 #include "pP_serial.h"
 
 // i2c input toggle. Uncomment to enable
@@ -96,11 +96,6 @@ void setup() {
   pinMode(GADJ_R3, INPUT); // declare input to break pull to ground
   Serial.begin(9600);
 
-  // Uncomment the following lines to use PCInt pins instead of hardware interrupt
-  //#include <PinChangeInterrupt.h>
-  //attachPCINT(digitalPinToPCINT(Z_TRG), pulse, FALLING);
-
-  // Uncomment the followoing line to use hardware interrupt pin
   attachInterrupt(digitalPinToInterrupt(Z_TRG), pulse, FALLING);
 
   Serial.println("Initializing Pyr0-Piezo Sensor...");
@@ -127,26 +122,21 @@ void loop() {
   // Set any new parameters from serial input
   updateParams();
   
-  // Check voltage of first and second stages and compare against thresholds
-  VComp = analogRead(VCOMP_SENSE_PIN);
-  diffCompL = (VComp - compInt) - Hyst;
-  diffCompH = (compInt - VComp) - Hyst;
-  
-  VAdj = analogRead(V_FOLLOW_PIN);
-  diffAdjL = (VAdj - senseInt) - Hyst;
-  diffAdjH = (senseInt - VAdj) - Hyst;
-
-  
   // Set the amplification gain factor
   adjustGain();
   
+  // Check voltage of first and second stages and compare against thresholds
+  adjustVin();
+  VComp = analogRead(VCOMP_SENSE_PIN);
+  VAdj = analogRead(V_FOLLOW_PIN);
+  
   // Voltage Follower adjustment
-  if (diffAdjL > 0 || diffAdjH > 0) {
+  if (VLast > Hyst || VLast < -Hyst) {
     adjustFollow();
   }
   
   // Voltage Comparator adjustment
-  if (diffCompL > 0 || diffCompH > 0) {
+  if (VLast > Hyst || VLast > -Hyst) {
     adjustComp();
   }
 

firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/pP_function.h

@@ -0,0 +1,142 @@
+/*
+  pyr0-piezo functions library
+  Created by Alan "pyr0ball" Weinstock 6/26/2019
+*/
+
+/*------------------------------------------------*/
+
+void pulse() {
+  digitalWrite(TRG_OUT, LOW);
+  sensorHReading = 1;
+  delay(TRG_DUR);
+  digitalWrite(TRG_OUT, HIGH);
+}
+
+
+/*------------------------------------------------*/
+
+long readVcc() {
+  // Read 1.1V reference against AVcc
+  // set the reference to Vcc and the measurement to the internal 1.1V reference
+  #if defined(__AVR_ATmega32U4__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
+    ADMUX = _BV(REFS0) | _BV(MUX4) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1);
+  #elif defined (__AVR_ATtiny24__) || defined(__AVR_ATtiny44__) || defined(__AVR_ATtiny84__)
+    ADMUX = _BV(MUX5) | _BV(MUX0);
+  #elif defined (__AVR_ATtiny25__) || defined(__AVR_ATtiny45__) || defined(__AVR_ATtiny85__)
+    ADMUX = _BV(MUX3) | _BV(MUX2);
+  #else
+    ADMUX = _BV(REFS0) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1);
+  #endif  
+
+  delay(2); // Wait for Vref to settle
+  ADCSRA |= _BV(ADSC); // Start conversion
+  while (bit_is_set(ADCSRA,ADSC)); // measuring
+
+  uint8_t low  = ADCL; // must read ADCL first - it then locks ADCH  
+  uint8_t high = ADCH; // unlocks both
+
+  long result = (high<<8) | low;
+
+  result = 1125300L / result; // Calculate Vcc (in mV); 1125300 = 1.1*1023*1000
+  return result; // Vcc in millivolts
+}
+ 
+/*------------------------------------------------*/
+ 
+ void adjustVin() {
+   VOld = Vin;
+	 Vin = readVcc(), DEC;
+   senseLong = senseThrs * 1024L;
+   compLong = compThrs * 1024L;
+   senseInt = (long long) senseLong / Vin;
+   compInt = (long long) compLong / Vin;
+   senseInt = (int) senseInt;
+   compInt = (int) compInt;
+ }
+
+/*------------------------------------------------*/
+
+ void adjustFollow() {
+    /* Compares diffs of threshold vs read value
+     if positive, adjusts the follower to within
+     the range set above*/
+    
+    ADJ_FOLLOW = (senseInt / 4);
+
+    // Analog output (PWM) of duty cycle
+    analogWrite(V_FOL_PWM, ADJ_FOLLOW);
+  }
+
+/*------------------------------------------------*/
+
+void adjustComp() {
+  ADJ_COMP = (compInt / 4);
+
+  analogWrite(VCOMP_PWM, ADJ_COMP);
+}
+  
+/*------------------------------------------------*/
+  
+void calibrateAlert() {
+  VLast = VOld - Vin;
+  if (VLast > Hyst || VLast < -Hyst ) {
+    ERR_STATE = 1;
+  }
+}
+  
+/*------------------------------------------------*/
+
+void adjustGain() {
+
+  if (GAIN_FACTOR == 0) {
+    pinMode(GADJ_R3, INPUT);
+    pinMode(GADJ_R2, INPUT);
+    pinMode(GADJ_R1, INPUT);
+    pinMode(GADJ_R0, INPUT);
+    ERR_STATE = 0;
+  }
+  else if (GAIN_FACTOR > 0) {
+    pinMode(GADJ_R3, OUTPUT);
+    digitalWrite(GADJ_R3, LOW);
+    pinMode(GADJ_R2, INPUT);
+    pinMode(GADJ_R1, INPUT);
+    pinMode(GADJ_R0, INPUT);
+    ERR_STATE = 0;
+  }
+  else if (GAIN_FACTOR > 1) {
+    pinMode(GADJ_R2, OUTPUT);
+    digitalWrite(GADJ_R2, LOW);
+    pinMode(GADJ_R1, INPUT);
+    pinMode(GADJ_R0, INPUT);
+    ERR_STATE = 0;
+  }
+  else if (GAIN_FACTOR > 2) {
+    pinMode(GADJ_R1, OUTPUT);
+    digitalWrite(GADJ_R1, LOW);
+    pinMode(GADJ_R0, INPUT);
+    ERR_STATE = 0;
+  }
+  else if (GAIN_FACTOR > 3) {
+    pinMode(GADJ_R0, OUTPUT);
+    digitalWrite(GADJ_R0, LOW);
+    ERR_STATE = 0;
+  }
+}
+  
+/*------------------------------------------------*/
+
+void checkError () {
+  if (ERR_STATE == 1) {
+    digitalWrite(ERR_LED, BlinkState);
+    BlinkState = !BlinkState;
+  }
+  else if (ERR_STATE == 0) {
+    BlinkState = LOW;
+    digitalWrite(ERR_LED, BlinkState);
+  }
+}
+
+/*------------------------------------------------*/
+  
+  
+// #endif

firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/pP_i2c.h

@@ -1,3 +1,5 @@
+#include <Wire.h>
+
 /*------------------------------------------------*/
 
 #ifdef I2C

firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/pP_serial.h

@@ -1,3 +1,127 @@
+
+/*------------------------------------------------*/
+
+void parseData() {
+
+  // split the data into its parts
+  
+  char * strtokIndx; // this is used by strtok() as an index
+  
+  strtokIndx = strtok(inputBuffer,",");      // get the first part - the string
+  strcpy(serialMessageIn, strtokIndx); // copy it to serialMessageIn
+  
+  strtokIndx = strtok(NULL, ",");   // this continues where the previous call left off
+  serialInt = atoi(strtokIndx);     // convert this part to an integer
+   
+  strtokIndx = strtok(NULL, ","); 
+  serialFloat = atof(strtokIndx);     // convert this part to a float
+
+}
+/*------------------------------------------------*/
+
+void identifyMarkers() {
+  
+  char x = Serial.read();
+//  char y = Wire.read();
+
+  if (x == endMarker) {
+    readInProgress = false;
+    serialIncoming = true;
+    inputBuffer[bytesRecvd] = 0;
+    parseData();
+  }
+
+  else if(readInProgress) {
+    inputBuffer[bytesRecvd] = x;
+    bytesRecvd ++;
+    if (bytesRecvd == buffSize) {
+      bytesRecvd = buffSize - 1;
+    }
+  }
+
+  else if (x == startMarker) { 
+    bytesRecvd = 0; 
+    readInProgress = true;
+  }
+  #ifdef I2C
+    if (y == endMarker) {
+      readInProgress = false;
+      serialIncoming = true;
+      inputBuffer[bytesRecvd] = 0;
+      parseData();
+    }
+
+    if(readInProgress) {
+      inputBuffer[bytesRecvd] = y;
+      bytesRecvd ++;
+      if (bytesRecvd == buffSize) {
+      bytesRecvd = buffSize - 1;
+      }
+    }
+
+    if (y == startMarker) { 
+      bytesRecvd = 0; 
+      readInProgress = true;
+    }
+  #endif
+}
+
+/*------------------------------------------------*/
+
+void updateTrigDuration() {
+  if (serialInt >= 0) {
+    TRG_DUR = serialInt;
+  }
+}
+/*------------------------------------------------*/
+
+void updateGainFactor() {
+  if (serialInt >= 0) {
+    GAIN_FACTOR = serialInt;
+  }
+}
+/*------------------------------------------------*/
+
+void updateVComp() {
+  if (serialInt >= 0) {
+    compInt = (serialFloat * 1024) / Vin;
+    //senseInt = compInt; // syncing these params til #24 is fixed
+  }
+}
+/*------------------------------------------------*/
+
+void updateVAdj() {
+  if (serialInt >= 0) {
+    senseInt = (serialFloat * 1024) / Vin;
+    //compInt = senseInt; // syncing these params til #24 is fixed
+  }
+}
+/*------------------------------------------------*/
+
+void updateHysteresis() {
+  if (serialInt >= 0) {
+    Hyst = serialInt;
+  }
+}
+/*------------------------------------------------*/
+
+/*------------------------------------------------*/
+
+void updateParams() {
+  if (strcmp(serialMessageIn, "TRG_D") == 0) {
+    updateTrigDuration();
+  }
+  else if (strcmp(serialMessageIn, "GAIN_F") == 0) {
+    updateGainFactor();
+  }
+  else if (strcmp(serialMessageIn, "VCOMP") == 0) {
+    updateVComp();
+  }
+  else if (strcmp(serialMessageIn, "VADJ") == 0) {
+    updateVAdj();
+  }
+}
+
 void serialInput() {
 
   // receive data from Serial and save it into inputBuffer
@@ -13,10 +137,14 @@ void serialInput() {
 /*------------------------------------------------*/
 
 void serialReply() {
+  #ifndef VERBOSE
     if (serialIncoming) {
     serialIncoming = false;
+  #endif
   #ifdef DEBUG
-    Serial.print("Comp Reference:");
+    Serial.print("Vcc:");
+    Serial.println(Vin);
+    Serial.print("Comp Sense:");
     Serial.print(VComp);
     Serial.print(" ");
     Serial.print("Comparator State:");
@@ -50,5 +178,7 @@ void serialReply() {
   Serial.print("Error State:");
   Serial.println(ERR_STATE);
   Serial.println("------------------");
+  #ifndef VERBOSE
   }
+  #endif
 }

firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/pP_volatile.h

@@ -4,18 +4,22 @@ volatile int ADJ_FOLLOW = 0;          // Variable for Follower adjustment
 volatile int ADJ_COMP = 0;            // Variable for Comparator adjustment
 volatile int ERR_STATE = 0;
 
-// Convert float to integer for adjustment functions
+int Vin = 5000;                   // input reference voltage in millivolts (multiply V by 1000)
-int senseInt = (senseThrs * 1024) / Vin;    // Voltage Follower upper converted to adg interger
+int VOld = 5000;                  // Variable to store previous cycle's Vin
-int compInt = (compThrs * 1024) / Vin;      // Upper threshold of Comparator before adjustment
+int VLast = 0;
+
+// Convert threshold values based on the input voltage
+long senseLong = senseThrs * 1024L;
+long compLong = compThrs * 1024L;
+long senseInt = senseLong / Vin;
+long compInt = compLong / Vin;
 
 // Voltage Comparator Adjustment parameters
-//float VCompRef = 0.00;                    // variable to store the float value read from the comparator reference
 int VComp = 0;
 int diffCompL = VComp - compInt;
 int diffCompH = compInt - VComp;
 
 // Voltage Follower Adjustment parameters
-//float vAdjRead = 0.00;                    // variable to store the value read from the follower
 int VAdj = 0;                    
 int diffAdjL = VAdj - senseInt;
 int diffAdjH = senseInt - VAdj;