Overview - Electric Imp Code

The imp is the small card with an SD Card form factor. Upon powering up, the imp contacts the cloud based Electric Imp server and checks for new software. If there is new software it downloads and runs it. If not, it runs its existing software. There are two components of software that are associated with each imp: the device software, which runs on the imp itself; and the agent software, which runs on the Electric Imp server in the cloud. The device code can interact with the hardware that the imp is connected to and it can communicate with the agent code. The agent code can communicate with the rest of the internet. Below is the agent and device code.

Agent and Device Code

Note that the agent code below is not exactly what is running for this class. It has been simplified to the code that you would run if you were building just one IOTemp. The code running for the class is provided further down the page. This code is more complicated because it allows us to assign each IOTemp to its own APEX Workspace. Also note that "your_ords_schema_goes_here" should be replaced with your workspace name in lower case. It is really the value shown in your workspace REST settings, which is typically your workspace name. As of this writing, it should always be lower case even though in the settings it is upper case.

Agent Code

//  Agent Code

/* 
   Change Log
   2014-12-31 ANielsen 1.00.00 Build 17 Created Agent Code
   2015-1-01  NNielsen 1.00.01 Build 19 Changed name of post function to "postToC2LED"
*/

/* GLOBALS and CONSTANTS -----------------------------------------------------*/

const ORDS_URL = "https://apex.oracle.com/pls/apex/%s/iotemp/temp";
const ORDS_SCHEMA = "your_ords_schema_goes_here";

/* CLASS AND GLOBAL FUNCTION DEFINITIONS -------------------------------------*/

local response = http.post(url, headers, body).sendsync();
	
	if(response.statuscode != 201 && response.statuscode != 200) {
	    server.log("error with http request, status: " + response.statuscode);
		server.log("error with http request: " + response.body);

local sleepTime = 20;
	    local blinkColor = "BLINK";
	    local JSONString = {"sleep_seconds": sleepTime, "color": blinkColor };

server.log("JSONString.color: " + JSONString.color);
	    device.send("led", JSONString);			
		return null;
	}

local JSONdata = http.jsondecode(response.body);
    
    server.log("Posted to C2 LED: "+data+", got return code: "+response.statuscode+", msg: "+response.body+" JSONdata.color: "+JSONdata.color+" JSONdata.sleep_seconds: "+JSONdata.sleep_seconds) ;
    //device.send("led", response.body);
    device.send("led", JSONdata);
}

/* REGISTER DEVICE CALLBACKS  ------------------------------------------------*/

device.on("data", function(datapoint) {
    postToC2LED(datapoint.temp, datapoint.id);
});

/* REGISTER HTTP HANDLER -----------------------------------------------------*/

// This agent does not need an HTTP handler

/* RUNTIME BEGINS HERE -------------------------------------------------------*/

server.log("TempBug Agent Running");

Device Code

// IOTemp Device Code
// https://github.com/electricimp/thermistor
//#require "Thermistor.class.nut:1.0"
#require "Thermistor.class.nut:1.0"

/* 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 = 0.1; // interval between wake-and-reads in minutes
ID <- hardware.getdeviceid(); // Get the deviceID once at the start

/* CLASS AND GLOBAL FUNCTION DEFINITIONS -------------------------------------*/
function setLeds(on, off) {
    foreach(led in on) led.write(1);
    foreach(led in off) led.write(0);
}

function blink() {
    setLeds([redLED, greenLED, yellowLED], []);
    imp.sleep(0.2);
    setLeds([], [redLED, greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([redLED, greenLED, yellowLED], []);
    imp.sleep(0.2);
    setLeds([], [redLED, greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([redLED, greenLED, yellowLED], []);
    imp.sleep(0.2);
    setLeds([greenLED], [redLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([yellowLED], [redLED, greenLED]);
    imp.sleep(0.2);
    setLeds([redLED], [greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([], [redLED, greenLED, yellowLED]);
}

function blinkRed() {
    setLeds([redLED], [greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([], [redLED, greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([redLED], [greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([], [redLED, greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([redLED], [greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([], [redLED, greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([redLED], [greenLED, yellowLED]);
    imp.sleep(0.2);
    setLeds([], [redLED, greenLED, yellowLED]);
}

function sendData() {
    therm_en_l.write(0);
    imp.sleep(0.001);

local datapoint = {
        "id" : ID,
        "temp" : format("%.2f",myThermistor.readF()),
        "impSSID" : "insumtest" //imp.getssid() + "_" + imp.getbssid() 
    }
    agent.send("data",datapoint);
    therm_en_l.write(1);
}

/* RUNTIME BEGINS HERE -------------------------------------------------------*/
// Configure Pins
therm_en_l <- hardware.pin8;
therm_en_l.configure(DIGITAL_OUT, 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;

// Configure LED pins
redLED    <- hardware.pin7;
redLED.configure(DIGITAL_OUT, 0);
yellowLED <- hardware.pin5;
yellowLED.configure(DIGITAL_OUT, 0);
greenLED  <- hardware.pin2;
greenLED.configure(DIGITAL_OUT, 0);

// instantiate sensor classes

// instantiate our thermistor class
myThermistor <- Thermistor(temp_sns, b_therm, t0_therm, 10, false);

// event listener to light the led
agent.on("led", lightLED)

// start loop
sendData();

Real Agent Code

//  Agent Code

/* 
   Change Log
   2014-12-31 ANielsen 1.00.00 Build 17 Created Agent Code
*/

/* GLOBALS and CONSTANTS -----------------------------------------------------*/

const ORDS_URL = "https://apex.oracle.com/pls/apex/%s/iotemp/temp";

/* CLASS AND GLOBAL FUNCTION DEFINITIONS -------------------------------------*/

function postToC2LED(data,id) {
    
    // call Anton's service to get the schema mapping for this imp_id
    local aUrl = format("https://apex.oracle.com/pls/apex/anton/impUtils/schema/%s/%s", id, data);
    local aHeaders = { "User-Agent" : "C2-Imp-Lib/0.1" };
    local aResponse = http.get(aUrl, aHeaders).sendsync();
    
    if(aResponse.statuscode != 200) {
		    server.log("error with step1 http request, status: " + aResponse.statuscode);
			server.log("error with step1 http request: " + aResponse.body);

local sleepTime = 20;
		    local blinkColor = "BLINKRED";
		    local JSONString = {"sleep_seconds": sleepTime, "color": blinkColor };

server.log("JSONString.color: " + JSONString.color);
		    device.send("led", JSONString);			
			return null;
	}
	
    // convert the json response and log the schema name
    local aJSONData = http.jsondecode(aResponse.body);
    //server.log("header: "+aResponse.headers);
    server.log("schema: "+ aJSONData.schema);
	
	if(aJSONData.schema == "xxinvalidxx") {
	    server.log("error getting schema, status: " + aResponse.statuscode);
		server.log("body: " + aResponse.body);
		
		local sleepTime = 20;
		local blinkColor = "REDYELLOWGREEN";
		local JSONString = {"sleep_seconds": sleepTime, "color": blinkColor };

server.log("JSONString.color: " + JSONString.color);
		device.send("led", JSONString);
		return null;
	}    
    
    // insert the schema retrieved above into the request url
	local url = format(ORDS_URL, aJSONData.schema);
	//local headers = { "User-Agent" : "C2-Imp-Lib/0.1" };
	
	local headers = { "Content-Type": "application/json" };
	
	local requestData = { "impid": id, "temp": data };
	local body = http.jsonencode(requestData);
	
	server.log(url);
	server.log(body);

local sleepTime = 20;
	    local blinkColor = "BLINK";
	    local JSONString = {"sleep_seconds": sleepTime, "color": blinkColor };

server.log("JSONString.color: " + JSONString.color);
	    device.send("led", JSONString);			
		return null;
	}

/* REGISTER DEVICE CALLBACKS  ------------------------------------------------*/

device.on("data", function(datapoint) {
    postToC2LED(datapoint.temp, datapoint.id);
});

/* REGISTER HTTP HANDLER -----------------------------------------------------*/

// This agent does not need an HTTP handler

/* RUNTIME BEGINS HERE -------------------------------------------------------*/

server.log("TempBug Agent Running");