Merge pull request #1 from electricimp/develop

Develop

Author: betzrhodes

Diff for: README.md

@@ -1,20 +1,20 @@
-#Thermistor Class
+#Thermistor
 
 This class makes it simple for an imp to read an NTC (“Negative Temperature Coefficient”) thermistor and determine the temperature. Thermistors are essentially temperature-dependent resistors. To use as a thermometer, a thermistor is used as half of a resistive divider, where the voltage across the full divider is known. The Imp then reads the voltage at the center of the divider to determine the ratio of resistance of the thermistor and the bias resistor (also the nominal resistance of the thermistor), [from which the temperature can be derived](http://en.wikipedia.org/wiki/Thermistor).
 
-**To add this library to your project, add** `#require "Thermistor.class.nut:1.0.0"` **to the top of your device code**
+**To add this library to your project, add** `#require "Thermistor.class.nut:2.0.0"` **to the top of your device code**
 
-## Usage
-
-### Hardware
+## Hardware
 
 A resistive divider can be formed with the thermistor on the top or the bottom; this class allows for either configuration. The top of the divider should be connected to the same rail as an imp’s V<sub>DDA</sub> pin (or V<sub>DD</sub> pin, in the case of the imp001, as V<sub>DD</sub> and V<sub>DDA</sub> are internally connected). The bottom of the divider should be connected to ground.
 
 The resistance of the bias resistor in the voltage divider should be equal to the nominal resistance of the thermistor (the resistance at T0).  This simplifies the temperature calculation and allows the largest dynamic range.
 
 The center of the divider must be connected to a pin capable of analog input. On the imp001, any pin can be used as an analog input. On the imp002 or imp003, only some pins can be configured this way, so check the [Imp Pin Mux chart](http://electricimp.com/docs/hardware/imp/pinmux/).
 
-### Software
+## Class Usage
+
+### Constructor: Thermistor(pin, b_therm, t0_therm, [points], [high_side_therm])
 
 The thermistor class takes three to five parameters (three required, two optional):
 
@@ -33,29 +33,34 @@ The ß and T0 parameters are all available on the thermistor datasheet:
 | ß | Characteristic of the thermistor. Most thermistors have many ß values listed, for various temperature ranges. Choose the value for the temperature range you will be operating in. |
 | T0 | Temperature at which the nominal resistance (R) of the thermistor is measured. Typically room temperature (~25ºC) |
 
-### Constructor
-
 ```squirrel
-const b_therm = 3988
-const t0_therm = 298.15
+const b_therm = 3988;
+const t0_therm = 298.15;
 
-pin <- hardware.pin9
+pin <- hardware.pinJ;
 
 // Thermistor on bottom of divider
-
-myThermistor <- Thermistor(pin, b_therm, t0_therm, 10, false)
+therm <- Thermistor(pin, b_therm, t0_therm, 10, false)
 ```
 
-### Class Methods
+## Class Methods
+
+### read()
+
+The *read()* method returns the temperature in Celsius.
+
+```squirrel
+local celsius = therm.read();
+server.log(celsius);
+```
 
-### Reading a thermistor
+### readK()
 
-The thermistor object provides three methods for reading the temperature: *readK()*, *readC()* and *readF()*. These return the temperature in Kelvin, Celsius and Fahrenheit, respectively.
+The *read()* method returns the temperature in Kelvin.
 
 ```squirrel
-local kelvin = therm.readK()
-local celsius = therm.readC()
-local fahrenheit = therm.readF()
+local kelvin = therm.readK();
+server.log(kelvin);
 ```
 
 ## License

Diff for: Thermistor.class.nut

@@ -1,8 +1,11 @@
-// Copyright (c) 2015 Electric Imp
+// Copyright (c) 2017 Electric Imp
 // This file is licensed under the MIT License
 // http://opensource.org/licenses/MIT
 
 class Thermistor {
+
+    static VERSION = "2.0.0";
+
     _beta = null;
     _t0 = null;
 
@@ -14,11 +17,22 @@ class Thermistor {
     constructor(pin, b, t0, points = 10, highSide = true) {
         _pin = pin;
         _pin.configure(ANALOG_IN);
-        _highSide = highSide;
+
+        if (typeof points == "boolean") {
+            _pointsPerRead = 10.0;
+            _highSide = points;
+        } else {
+            _pointsPerRead = points * 1.0;
+            _highSide = highSide;
+        }
 
         _beta = b * 1.0;
         _t0 = t0 * 1.0;
-        _pointsPerRead = points * 1.0;
+    }
+
+    // read thermistor in Celsius
+    function read() {
+        return (readK() - 273.15);
     }
 
     // read thermistor in Kelvin
@@ -39,14 +53,4 @@ class Thermistor {
 
         return (_t0 * _beta) / (_beta - _t0 * ln_therm);
     }
-
-    // read thermistor in Celsius
-    function readC() {
-        return this.readK() - 273.15;
-    }
-
-    // read thermistor in Fahrenheit
-    function readF() {
-        return ((this.readK() - 273.15) * 9.0 / 5.0 + 32.0);
-    }
 }

Diff for: examples/tempbug-battery/README.md renamed to examples/Battery_Thermistor/README.md

@@ -1,16 +1,16 @@
 #Tempbug Battery Example
-This example shows how to read a simple NTC thermistor and post the data to [Xively](https://xively.com/) every 15 minutes to be graphed. 
+This example shows how to read a simple NTC thermistor and post the data to the agent every 15 minutes.
 
-In this example, the resistive divider is between 3.3V and Imp Pin8, which is configured as an open-drain output. This allows the Imp to stop current from flowing through the divider by driving Pin8 high, which allows for very long operation on battery. 
+In this example, the resistive divider is between 3.3V and Imp Pin8, which is configured as an open-drain output. This allows the Imp to stop current from flowing through the divider by driving Pin8 high, which allows for very long operation on battery.
 
 ##Hardware Configuration
 
 Form a resistive divider from the 3.3V pin on the Electric Imp Breakout to Ground with a 100kΩ resistor and a 100kΩ NTC thermistor. The example code assumes the NTC thermistor is on the bottom half of the divider, connected between the analog input and Imp Pin8. Imp Pin9 should be connected to the middle of the divider.
 
 <img class="img-rounded" src="tempbug_battery_100k.png" width="600">
 
-For more information on building a battery-powered temperature sensor with Electric Imp and a Thermistor, see the [Tempbug Instructable.](http://www.instructables.com/id/TempBug-internet-connected-thermometer/).
+For more information on building a battery-powered temperature sensor with Electric Imp and a Thermistor, see the [Tempbug Instructable](http://www.instructables.com/id/TempBug-internet-connected-thermometer/).
 
 
 ##Software Operation
-Unlike the simple example, this example does not reschedule readings with imp.wakeup. Instead, the Imp is programmed to take a single reading, then go to deep sleep with a timed wakeup. When the Imp wakes from deep sleep, the entire device firmware is reloaded and run from the beginning, so the loop is implicit. 
+Unlike the simple example, this example does not reschedule readings with imp.wakeup. Instead, the Imp is programmed to take a single reading, then go to deep sleep with a timed wakeup. When the Imp wakes from deep sleep, the entire device firmware is reloaded and run from the beginning, so the loop is implicit.

Diff for: examples/Battery_Thermistor/tempbug.agent.nut

@@ -0,0 +1,11 @@
+// Copyright (c) 2015 Electric Imp
+// This file is licensed under the MIT License
+// http://opensource.org/licenses/MIT
+
+/* REGISTER DEVICE CALLBACKS  ------------------------------------------------*/
+
+device.on("data", function(datapoint) {
+    // Log our datapoint
+    server.log(http.jsonencode(datapoint));
+    // Add code here to upload data to a web service
+});

Diff for: examples/Battery_Thermistor/tempbug.device.nut

@@ -0,0 +1,47 @@
+// Copyright (c) 2015 Electric Imp
+// This file is licensed under the MIT License
+// http://opensource.org/licenses/MIT
+
+// Include the Thermistor Library
+#require "Thermistor.class.nut:2.0.0"
+
+/* GLOBALS and CONSTANTS -----------------------------------------------------*/
+
+// all calculations are done in Kelvin
+// these are constants for this particular thermistor; if using a different one,
+// check your datasheet
+const b_therm = 3988;
+const t0_therm = 298.15;
+const WAKEINTERVAL_MIN = 15; // interval between wake-and-reads in minutes
+
+
+/* RUNTIME BEGINS HERE -------------------------------------------------------*/
+
+// Configure Pins
+// pin 8 is driven high to turn off temp monitor (saves power) or low to read
+therm_en_l <- hardware.pin8;
+therm_en_l.configure(DIGITAL_OUT);
+therm_en_l.write(1);
+// pin 9 is the middle of the voltage divider formed by the NTC - read the analog voltage to determine temperature
+temp_sns <- hardware.pin9;
+
+// instantiate our thermistor class
+myThermistor <- Thermistor(temp_sns, b_therm, t0_therm, 10, false);
+
+therm_en_l.write(0);
+imp.sleep(0.001);
+local id = hardware.getdeviceid();
+local datapoint = {
+    "id" : id,
+    "temp" : format("%.2f",myThermistor.read())
+}
+agent.send("data",datapoint);
+therm_en_l.write(1);
+
+//Sleep for 15 minutes and 1 second, minus the time past the 0:15
+//so we wake up near each 15 minute mark (prevents drifting on slow DHCP)
+imp.onidle( function() {
+    server.sleepfor(1 + WAKEINTERVAL_MIN*60 - (time() % (WAKEINTERVAL_MIN*60)));
+});
+
+// full firmware is reloaded and run from the top on each wake cycle, so no need to construct a loop

Diff for: examples/tempbug-battery/tempbug_battery_100k.png renamed to examples/Battery_Thermistor/tempbug_battery_100k.png

@@ -1,7 +1,7 @@
 #Tempbug Simple Example
-This example shows how to read a simple NTC thermistor and post the data to [Xively](https://xively.com/) every 15 minutes to be graphed. 
+This example shows how to read a simple NTC thermistor and post the data to the agent every 15 minutes.
 
-No consideration is made in this example for battery life. Please see tempbug-battery.
+No consideration is made in this example for battery life. Please see Battery-Thermistor example for power saving example.
 
 ##Hardware Configuration
 

Diff for: examples/tempbug-simple/README.md renamed to examples/Simple_Thermistor/README.md

@@ -0,0 +1,11 @@
+// Copyright (c) 2015 Electric Imp
+// This file is licensed under the MIT License
+// http://opensource.org/licenses/MIT
+
+/* REGISTER DEVICE CALLBACKS  ------------------------------------------------*/
+
+device.on("data", function(datapoint) {
+    // Log our datapoint
+    server.log(http.jsonencode(datapoint));
+    // Add code here to upload data to a web service
+});

Diff for: examples/tempbug-simple/tempbug-simple_bb.png renamed to examples/Simple_Thermistor/tempbug-simple_bb.png

@@ -0,0 +1,46 @@
+// Copyright (c) 2015 Electric Imp
+// This file is licensed under the MIT License
+// http://opensource.org/licenses/MIT
+
+// Include the Thermistor Library
+#require "Thermistor.class.nut:2.0.0"
+
+/* GLOBALS and CONSTANTS -----------------------------------------------------*/
+
+// all calculations are done in Kelvin
+// these are constants for this particular thermistor; if using a different one,
+// check your datasheet
+const b_therm = 3988;
+const t0_therm = 298.15;
+const INTERVAL = 900; // interval between wake-and-reads in seconds (15 minutes)
+
+function getTemp() {
+	// schedule the next temperature reading
+	imp.wakeup(INTERVAL, getTemp);
+
+	// hardware id is used to separate feeds on Xively, so provide it with the data
+	local id = hardware.getdeviceid();
+
+	// tempreature can also be returned in Kelvin or Celsius
+	local datapoint = {
+	    "id" : id,
+	    "temp" : format("%.2f",myThermistor.read())
+	}
+
+	server.log("Temp: " + datapoint.temp);
+	agent.send("data", datapoint);
+}
+
+/* RUNTIME BEGINS HERE -------------------------------------------------------*/
+
+// Configure Pins
+// Pin 7 is the middle of the voltage divider formed by the NTC - read the analog voltage to determine temperature
+temp_sns <- hardware.pin7;
+
+// Instantiate our thermistor class
+// This shows the thermistor on the bottom of the divider
+myThermistor <- Thermistor(temp_sns, b_therm, t0_therm, 10, false);
+
+// This function will schedule itself to re-run after it is first called
+// Just call it once to start the loop.
+getTemp();