Added skeleton for PIR sensor; non-functional and omitting for the time being

README.md

@@ -25,6 +25,10 @@ In the code you'll find the following variables which may need tweaking
   * SLEEP_INTERVAL : The amount of time (in miliseconds) that the device sleeps for between checks
   * ALERT_LEVEL : The battery level that generates an alert. This must be set between 1 and 32%, inclusive
 
+Known Issues
+=
+Please see the TODO.md document for current, known issues.
+
 Code License
 =
 All code is licensed under the Apache 2 License (http://www.apache.org/licenses/LICENSE-2.0) unless otherwise specified.
@@ -35,6 +39,7 @@ The following external libraries are included and may not be licensed under the
   * SparkFun Lipo Fuel Gauge Library / Example code
   * "Sleepy" class from https://github.com/jcw/jeelib/
   * Metro timing lib from https://github.com/thomasfredericks/Metro-Arduino-Wiring
+  * SharpIR lib from http://playground.arduino.cc/Main/SharpIR
 
 Non-Code License
 =

TODO.md

@@ -3,3 +3,4 @@
   * Add note about adjusting values for distance
   * Finish Fritzing documentation (breadboard / schematic)
   * Update BoM so it's complete
+  * Fix PIR distance sensor code

src/SharpIR.cpp

@@ -0,0 +1,128 @@
+/************************************************************************************************************
+ * SharpIR.h - Arduino library for retrieving distance (in cm) from the analog GP2Y0A21Y and GP2Y0A02YK     *
+ * Distance sensors                                                                                         *
+ * Copyright 2014 Dr. Marcal Casas-Cartagena (marcal.casas@gmail.com)                                       *
+ * Last update: 07.01.2014                                                                                  *
+ ************************************************************************************************************
+ 
+ ************************************************************************************************************
+ * This library is free software; you can redistribute it and/or                                            *
+ * modify it under the terms of the GNU Lesser General Public                                               *
+ * License as published by the Free Software Foundation; either                                             *
+ * version 2.1 of the License, or (at your option) any later version.                                       *
+ *                                                                                                          *
+ * This library is distributed in the hope that it will be useful,                                          *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of                                           *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU                                        *
+ * Lesser General Public License for more details.                                                          *
+ *                                                                                                          *
+ * You should have received a copy of the GNU Lesser General Public                                         *
+ * License along with this library; if not, write to the Free Software                                      *
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA                               *
+ ***********************************************************************************************************/
+
+
+// The Sahrp IR sensors are cheap but somehow unreliable. I've found that when doing continous readings to a
+// fix object, the distance given oscilates quite a bit from time to time. For example I had an object at
+// 31 cm. The readings from the sensor were mainly steady at the correct distance but eventually the distance
+// given dropped down to 25 cm or even 16 cm. That's quite a bit and for some applications it is quite
+// unacceptable. I checked the library http://code.google.com/p/gp2y0a21yk-library/ by Jeroen Doggen
+// (jeroendoggen@gmail.com) and what the author was doing is to take a bunch of readings and give an average of them
+
+// The present library works similary. It reads a bunch of readings (avg), it checks if the current reading
+// differs a lot from the previous one (tolerance) and if it doesn't differ a lot, it takes it into account
+// for the mean distance.
+// The distance is calculated from a formula extracted from the graphs on the sensors datasheets
+// After some tests, I think that a set of 20 to 25 readings is more than enough to get an accurate distance
+// Reading 25 times and return a mean distance takes 53 ms. For my application of the sensor is fast enough.
+// This library has the formulas to work with the GP2Y0A21Y and the GP2Y0A02YK sensors but exanding it for
+// other sensors is easy enough.
+
+
+#include "Arduino.h"
+#include "SharpIR.h"
+
+
+
+SharpIR::SharpIR(int irPin, int avg, int tolerance, int sensorModel) {
+  
+    _irPin=irPin;
+    _avg=avg;
+    _tol=tolerance/100;
+    _model=sensorModel;
+    
+    analogReference(DEFAULT);
+ 
+}
+
+
+// When you initialize the library object on your sketch you have to pass all the above parameters:
+
+// irPin is obviously the pin where the IR sensor is attached
+// avg is the number of readings the library does
+// tolerance indicates how similar a value has to be from the last value to be taken as valid. It should be a
+//    value between 0 and 100, like a %. A value of 93 would mean that one value has to be, at least, 93% to the
+//    previous value to be considered as valid.
+// sensorModel is a int to differentiate the two sensor models this library currently supports:
+//    1080 is the int for the GP2Y0A21Y and 20150 is the int for GP2Y0A02YK. The numbers reflect the
+//    distance range they are designed for (in cm)
+ 
+
+
+
+int SharpIR::cm() {
+    
+    int raw=analogRead(_irPin);
+    float voltFromRaw=map(raw, 0, 1023, 0, 5000);
+    
+    int puntualDistance;
+    
+    if (_model==1080) {
+        
+        puntualDistance=27.728*pow(voltFromRaw/1000, -1.2045);
+        
+    }else if (_model==20150){
+    
+        puntualDistance=61.573*pow(voltFromRaw/1000, -1.1068);
+        
+    }
+    
+    
+    return puntualDistance;
+
+
+}
+
+
+
+int SharpIR::distance() {
+
+    _p=0;
+    _sum=0;
+
+    
+    for (int i=0; i<_avg; i++){
+        
+        int foo=cm();
+        
+        if (foo>=(_tol*_previousDistance)){
+        
+            _previousDistance=foo;
+            _sum=_sum+foo;
+            _p++;
+            
+        }
+        
+        
+    }
+
+    
+    int accurateDistance=_sum/_p;
+    
+    return accurateDistance;
+
+}
+
+
+
+

src/SharpIR.h

@@ -0,0 +1,49 @@
+/************************************************************************************************************
+ * SharpIR.h - Arduino library for retrieving distance (in cm) from the analog GP2Y0A21Y and GP2Y0A02YK     *
+ * Distance sensors                                                                                         *
+ * Copyright 2014 Dr. Marcal Casas-Cartagena (marcal.casas@gmail.com)                                       *
+ ************************************************************************************************************
+
+ ************************************************************************************************************
+ * This library is free software; you can redistribute it and/or                                            *
+ * modify it under the terms of the GNU Lesser General Public                                               *
+ * License as published by the Free Software Foundation; either                                             *
+ * version 2.1 of the License, or (at your option) any later version.                                       *
+ *                                                                                                          *
+ * This library is distributed in the hope that it will be useful,                                          *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of                                           *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU                                        *
+ * Lesser General Public License for more details.                                                          *
+ *                                                                                                          *
+ * You should have received a copy of the GNU Lesser General Public                                         *
+ * License along with this library; if not, write to the Free Software                                      *
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA                               *
+ ***********************************************************************************************************/
+
+#ifndef SharpIR_h
+#define SharpIR_h
+
+#include "Arduino.h"
+
+class SharpIR
+{
+  public:
+    SharpIR (int irPin, int avg, int tolerance, int sensorModel);
+    int distance();
+    
+    
+  private:
+    
+    int cm();
+    
+    int _irPin;
+    int _model;
+    int _avg;
+    int _p;
+    int _sum;
+    int _previousDistance;
+    int _tol;
+    
+};
+
+#endif

src/src.ino

@@ -6,6 +6,7 @@
 #include "MAX1704.h"
 #include "Sleepy.h"
 #include "Metro.h"
+#include "SharpIR.h"
 #include "Adafruit_NeoPixel.h"
 #ifdef __AVR__
   #include <avr/power.h>
@@ -15,9 +16,10 @@
 // Various defines / pins / etc
 //  TWEAK THESE ACCORDINGLY
 // //////////
-#define DEBUG false
+#define DEBUG true
 #define INTERACTIVE_DEBUG false
 #define USE_SLEEP true
+#define USE_PIR false
 #define SLEEP_INTERVAL 500 // miliseconds
 #define ALERT_LEVEL 15 // battery alert level (%) [1-32% are valid values here]
 #define POT_BRIGHT A0
@@ -25,6 +27,7 @@
 #define PIN_ALWAYS_ON 9 // Switch that enables always on/off of pixels
 #define PIN_WHITE 12 // Switch that switches between color wiper and white color
 #define PIN_DOOR 11 // Door sensor pin
+#define PIN_PIR A2 // Pin with PIR distance sensor
 #define PIN_NEO 6 // Pin with the pixel comm line
 #define NEO_PIX_NUM 2 // FIXME: this should be 5 for final build for safe lighting
 
@@ -45,6 +48,10 @@ bool white = false;
 bool max_found = false;
 bool door_open = false;
 bool lights_on = false;
+#if USE_PIR
+SharpIR sharp(PIN_PIR, 25, 93, 1080);
+int distance = 0;
+#endif
 
 // //////////
 // Various function definitions
@@ -76,6 +83,7 @@ void setup() {
   pinMode(PIN_ALWAYS_ON, INPUT_PULLUP);
   pinMode(PIN_WHITE, INPUT_PULLUP);
   pinMode(PIN_DOOR, INPUT_PULLUP);
+  pinMode(PIN_PIR, INPUT);
   pinMode(POT_BRIGHT, INPUT);
   pinMode(POT_COLOR, INPUT);
   
@@ -135,6 +143,9 @@ void read_values() {
   always_on = (digitalRead(PIN_ALWAYS_ON) == LOW); // Toggle button pressed == ALWAYS ON
   white = (digitalRead(PIN_WHITE) == LOW); // Shorted pin to enable white color for LEDs
   door_open = (digitalRead(PIN_DOOR) == HIGH); // SparkFun door sensor is indicating door is open (NO for door closed state, set as input_pullup so the logic is inverted)
+  #if USE_PIR
+    distance = sharp.distance();
+  #endif
   lights_on = always_on || (door_open); // Take a look at all appropriate values and set lights on/off as appropriate
 }
 
@@ -253,6 +264,10 @@ void print_debug() {
     Serial.println(always_on);
     Serial.print("Door sensor: ");
     Serial.println(door_open);
+    #if USE_PIR
+      Serial.print("PIR Sensor: ");
+      Serial.println(distance);
+    #endif
     Serial.println("----------");
     delay(250);
   }