Code example to regularly report light level and temperature over Sigfox on the QW dev kit

Dependencies:   QW_Sensors mbed

This is a code example that demonstrates sending the light level sensor and temperature sensor output over Sigfox at regular time intervals.

The payload that is sent over the network consists of 3 bytes:

  • two bytes light level reading
  • one bye temperature reading.

Use this code example as a start to connect your own device over Sigfox with the Quicksand QW development kit.

Revision:
0:9a93fff79b27
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Mar 08 09:46:45 2016 +0000
@@ -0,0 +1,250 @@
+/* This program is an example application that measures the temperature and the light level
+ * and transmits the sensor readings over the Sigfox network.
+ * A transmission is scheduled every 15 minutes, and the user can force a transmission 
+ * by pressing the user button one.
+ * 
+ * The data format of the Sigfox payload is:
+ * First two bytes of the payload: light level as unsigned 16-bit value.
+ * Third byte of the payload: temperature as signed 8-bit value
+ * 
+ * Open a serial console to the board to get a debug trace.
+ *
+ * Note: this is a very basic example that has no energy usage optimization. The controller is not put in sleep mode
+ * in between readings/Sigfox transmissions in order to keep the code flow linear and short.
+ *
+ * In the current configuration, the temperature sensor is read once per second and a Sigfox transmission is scheduled every 15 minutes. 
+ * Adapt the defines TX_INTERVAL and MEASURE_INTERVAL to change these settings.
+ */
+
+#include "mbed.h"
+#include "math.h"
+#include "LinearTempSensor.h"
+#include "VCNL4010.h"
+
+#define SER_BUFFER_SIZE 32
+
+// Interval in minutes for scheduled Tx
+#define TX_INTERVAL 15
+
+// Temperature measure interval in seconds
+#define MEASURE_INTERVAL 1
+
+/* The 4 onboard LEDs */
+DigitalOut LED_0 (PB_6);
+DigitalOut LED_1 (PA_7);
+DigitalOut LED_2 (PA_6);
+DigitalOut LED_3 (PA_5);
+
+/* The 2 user buttons */
+InterruptIn SW1(PA_8);
+InterruptIn SW2(PB_10);
+
+/* Proximity and ambient light sensor*/
+VCNL40x0 VCNL4010(PB_9, PB_8, VCNL40x0_ADDRESS);      // SDA, SCL pin and I2C address
+
+/*Temperature sensor */
+LinearTempSensor sensor(PA_0, 40);
+
+/* Ticker for scheduled transmissions */
+Ticker tTX;
+Ticker tSense;
+
+/* Function prototypes */
+void sw1interrupt();
+void sw2interrupt();
+void sertmout();
+bool read_acc(int& x, int& y, int& z);
+bool modem_command_check_ok(char * command);
+void modem_setup();
+void txData();
+void dataScheduledTX();
+void senseTemperature();
+
+bool ser_timeout = false;
+bool handleIRQ1 = false;
+
+/* Serial port over USB */
+Serial pc(USBTX, USBRX);
+
+/* Serial connection to sigfox modem */
+Serial modem(PA_9, PA_10);
+
+int main()
+{
+    /* Storage for VCNL4010 readout */
+    unsigned char ID=0, Current=0;
+    //unsigned int  ProxiValue=0, AmbiValue=0;
+
+    /* Variables that will store analog temperature sensor reading */
+    //float Tav, To;
+    
+    /* Setup TD120x */
+    wait(3);
+    modem_setup();
+
+    /* Turn off all LED */
+    LED_0 = 1;
+    LED_1 = 1;
+    LED_2 = 1;
+    LED_3 = 1;
+
+    /* Setup button interrupts */
+    SW2.fall(&sw2interrupt);
+    SW1.fall(&sw1interrupt);
+
+    /* Read VCNL40x0 product ID revision register */
+    VCNL4010.ReadID (&ID);
+    pc.printf("\nVCNL4010 Product ID Revision Register: %d", ID);
+
+    VCNL4010.SetCurrent (20);                        // Set current to 200mA
+    VCNL4010.ReadCurrent (&Current);                 // Read back IR LED current
+    pc.printf("\nVCNL4010 IR LED Current: %d\n\n", Current);
+
+    // Sense temperature for the first time
+    senseTemperature();
+    
+    wait_ms(3000);                                   // wait 3s (only for display)
+
+    tTX.attach(&dataScheduledTX, TX_INTERVAL*60);               // Attach the timer for TX
+    tSense.attach(&senseTemperature, MEASURE_INTERVAL);           // Attach the timer for sensing the temperature
+    
+    while(1) 
+    {
+        /*
+        // VCNL4010 reading 
+        VCNL4010.ReadProxiOnDemand (&ProxiValue);    // read prox value on demand
+        VCNL4010.ReadAmbiOnDemand (&AmbiValue);      // read ambi value on demand
+        // MCP9700 reading 
+        Tav  = sensor.GetAverageTemp();
+        To   = sensor.GetLatestTemp();
+
+        pc.printf("\n\rVCNL4010 report: Proximity: %5.0i cts, Ambient light: %5.0i cts, Illuminance: %7.2f lx\n\rMCP9700 report:  Average Temp: %.2f %cC, Latest Temp: %.2f %cC", ProxiValue, AmbiValue, AmbiValue/4.0, Tav, 176, To, 176);
+        wait_ms(5000);
+        */
+        
+        if (handleIRQ1) {
+            txData();
+            handleIRQ1 = false;
+        }
+    }
+}
+
+void modem_setup()
+{
+    /* Reset to factory defaults */
+    if(modem_command_check_ok("AT&F")) 
+    {
+        pc.printf("Factory reset succesfull\r\n");
+    }
+    else 
+    {
+        pc.printf("Factory reset TD120x failed\r\n");
+    }
+    /* Disable local echo */
+    modem.printf("ATE0\n");
+    if(modem_command_check_ok("ATE0")) 
+    {
+        pc.printf("Local echo disabled\r\n");
+    }
+    /* Write to mem */
+    if(modem_command_check_ok("AT&W")) 
+    {
+        pc.printf("Settings saved!\r\n");
+    }
+}
+
+bool modem_command_check_ok(char * command)
+{
+    /* first clear serial data buffers */
+    while(modem.readable()) modem.getc();
+    /* Timeout for response of the modem */
+    Timeout tmout;
+    ser_timeout = false;
+    /* Buffer for incoming data */
+    char responsebuffer[6];
+    /* Flag to set when we get 'OK' response */
+    bool ok = false;
+    bool error = false;
+    /* Print command to TD120x */
+    modem.printf(command);
+    /* Newline to activate command */
+    modem.printf("\n");
+    /* Wait untill serial feedback, max 3 seconds before timeout */
+    tmout.attach(&sertmout, 3.0);
+    while(!modem.readable()&& ser_timeout == false);
+    while(!ok && !ser_timeout && !error) 
+    {
+        if(modem.readable()) 
+        {
+            for(int i = 0; i < 5; i++)
+            {
+                responsebuffer[i] = responsebuffer[i+1];
+            }
+            responsebuffer[5] = modem.getc();
+            if(responsebuffer[0] == '\r' && responsebuffer[1] == '\n' && responsebuffer[2] == 'O' && responsebuffer[3] == 'K' && responsebuffer[4] == '\r' && responsebuffer[5] == '\n' ) 
+            {
+                ok = true;
+            }
+            else if(responsebuffer[0] == '\r' && responsebuffer[1] == '\n' && responsebuffer[2] == 'E' && responsebuffer[3] == 'R' && responsebuffer[4] == 'R' && responsebuffer[5] == 'O' ) 
+            {
+                error = true;
+            }
+        }
+    }
+    tmout.detach();
+    return ok;
+}
+
+/* Button 1 ISR */
+void sw1interrupt()
+{
+    pc.printf("\n\rButton 1 pressed\n\r");
+    LED_1 = 0;
+    handleIRQ1 = true;
+}
+
+/* Button 2 ISR */
+void sw2interrupt()
+{
+    pc.printf("\n\rButton 2 pressed\n\r");
+}
+
+void dataScheduledTX()
+{
+    pc.printf("\n\rScheduled Sigfox TX triggered\n\r");
+    LED_1 = 0;
+    handleIRQ1 = true;
+}
+
+/* ISR for serial timeout */
+void sertmout()
+{
+    ser_timeout = true;
+}
+
+/* TX data over Sigfox */
+void txData (){
+
+    unsigned int ambiValue = 0;
+    int8_t   tAvgByte = 0;
+    uint16_t ambiValueShort;
+    float    tAvg;
+    char     command[32];
+    
+    VCNL4010.ReadAmbiOnDemand (&ambiValue);      // read ambi value on demand
+    tAvg = sensor.GetAverageTemp();
+    tAvgByte = (int8_t)tAvg;
+    ambiValueShort = (uint16_t)ambiValue;
+
+    sprintf(command, "AT$SF=%04X%02X,2,0\n", ambiValueShort, tAvgByte);
+    
+    pc.printf("Sending ambient light level %i cts and temperature %i degrees C over Sigfox\n", ambiValueShort, tAvgByte);
+    pc.printf("using modem command: %s", command);
+    modem_command_check_ok(command);
+    LED_1 = 1;
+}
+
+void senseTemperature() {
+    float vOut = sensor.Sense();
+    //pc.printf("\n\rMCP9700 reading:  Vout: %.2f mV", vOut);
+}