added Kalman filter example

.gitignore

@@ -2,3 +2,4 @@
 WifiOfficeSensorsPachube/passwords.h
 *.DS_Store
 *.fzz
+*.vscode*

KalmanFilter/KalmanFilter.ino

@@ -0,0 +1,42 @@
+/*
+  Kalman filter
+
+  Reads an analog sensor on pin A0 and smooths the result with a Kalman filter.
+  Uses the SimpleKalmanFilter library (https://github.com/denyssene/SimpleKalmanFilter)
+  Install the library from the Library Manager.
+  The best way to see the result is to use the Serial Plotter
+  from the Tools menu in the Arduino IDE (command-shift-L).
+
+  Circuit:
+    Analog sensor attached to pin A0 (use something noisy)
+
+  created 19 Jan 2019
+  by Tom Igoe
+*/
+#include <SimpleKalmanFilter.h>
+
+// first 2 numbers are the amount of variation,
+// third is how fast the measurement moves. recommended: 0.01.
+// change these values and see how the result changes.
+SimpleKalmanFilter filter(2, 2, 0.01);
+
+int intensity = 0;
+int lastEstimate = 0;
+int peakValue = 0;
+int threshold = 605;
+
+void setup() {
+  // initialize serial communication:
+  Serial.begin(9600);
+}
+
+void loop() {
+  // read the input:
+  float sensorValue = analogRead(A0);
+  Serial.print(sensorValue);
+  Serial.print(",");
+
+  // calculate the estimated value with Kalman Filter
+  float estimate = filter.updateEstimate(sensorValue);
+  Serial.println(estimate);
+}

TMP36/TMP36.ino

@@ -12,7 +12,7 @@ void loop() {
   // read the value from the sensor:
   int sensorValue = analogRead(A0);
   // convert the reading to millivolts:
-  float voltage = sensorValue *  (5.0/ 1024.0); 
+  float voltage = sensorValue *  (3.3/ 1024.0); 
   // convert the millivolts to temperature celsius:
   float temperature = (voltage - 0.5)/0.01;
   // print the temperature:

TMP36Datalogger/TMP36Datalogger.ino

@@ -30,13 +30,11 @@ Temperature and Humidity sensors
 const int chipSelect = 4;         // CS pin for the SD card. Will change depending on your shield or module
 boolean cardReady = false;
 
-float voltage = 5.0;              // analog reference voltage
+float voltage = 1.3;              // analog reference voltage
 const float resolution = 1024.0;  // A-to-D resolution
 
 float tempOffset = 0.5;           // temp sensor offset
 float tempSlope = 0.01;           // temp sensor slope
-float rhSlope = 0.0062 * voltage; // humidity sensor slope
-float rhOffset = 0.16 * voltage;  // humidity sensor offset
 
 void setup() {
   Serial.begin(9600);
@@ -46,8 +44,7 @@ void setup() {
 void loop() {
   float temperature = tempRead(A0);                // get a temperature reading
   delay(2);                                        // give the ADC time to settle
-  float humidity = humidityRead(A1, temperature);  // get a humidity reading
-  writeToCard(temperature, humidity);              // write the readings to the SD card
+  writeToCard(temperature, 0);              // write the readings to the SD card
   delay(1000);                                     // wait a second
 }
 
@@ -62,18 +59,6 @@ float tempRead(int pinNumber) {  // read the temperature sensor:
 }
 
 
-float humidityRead(int pinNumber,float temp) {
-  // read the humidity sensor:
-  int humiditySensor = analogRead(pinNumber);
-  // convert to voltage:
-  float humidityVoltage = (humiditySensor/resolution) * voltage; 
-  // convert to relative humidity (rH): 
-  float sensorRH = (humidityVoltage - rhOffset) / rhSlope;
-  // adjust for temperature:
-  float trueRH = sensorRH / (1.0546 - (0.00216 * temp)); 
-  return trueRH;
-} 
-
 boolean initializeCard() {
   Serial.print("Initializing SD card...");
   // make sure that the default chip select pin is set to