Diff: main.cpp

Revision:

0:2629b8684f00

Child:

1:cc6bfdd667ea

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Mar 17 08:44:50 2016 +0000
@@ -0,0 +1,99 @@
+#include "mbed.h"
+
+/*******************************************************************************
+ *******************************   DEFINES   ***********************************
+ ******************************************************************************/
+ 
+/** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */
+ 
+/** Si7013 Read Temperature Command */
+#define SI7013_READ_TEMP        0xE0 /* Read previous T data from RH measurement
+                                        command*/
+/** Si7013 Read RH Command */
+#define SI7013_READ_RH          0xE5 /* Perform RH (and T) measurement. */
+/** Si7013 Read ID */
+#define SI7013_READ_ID1_1       0xFA
+#define SI7013_READ_ID1_2       0x0F
+#define SI7013_READ_ID2_1       0xFc
+#define SI7013_READ_ID2_2       0xc9
+/** Si7013 Read Firmware Revision */
+#define SI7013_READ_FWREV_1     0x84
+#define SI7013_READ_FWREV_2     0xB8
+ 
+/** I2C device address for Si7013 */
+#define SI7013_ADDR      0x82
+/** I2C device address for Si7021 */
+#define SI7021_ADDR      0x80
+ 
+ 
+/** Device ID value for Si7013 */
+#define SI7013_DEVICE_ID 0x0D
+/** Device ID value for Si7020 */
+#define SI7020_DEVICE_ID 0x14
+/** Device ID value for Si7021 */
+#define SI7021_DEVICE_ID 0x15
+ 
+/** @endcond */
+
+/*******************************************************************************
+ *******************************  Variables  ***********************************
+ ******************************************************************************/
+
+//LED1
+DigitalOut myled(LED1);
+//I2C-bus with RHT sensor (Si7021) on Happy Gecko STK
+I2C tempSensor(PD6, PD7);
+//And enable line for the sensor
+DigitalOut SENS_EN(PC8);
+
+uint8_t  _address = 0;
+uint8_t  _rx_buf[8] = {0};
+uint8_t  _tx_buf[2] = {0};
+ 
+uint32_t _rhData = 0;
+int32_t  _tData = 0;
+
+/*******************************************************************************
+ *******************************     FUNC    ***********************************
+ ******************************************************************************/
+
+int32_t readTemperature(void) {
+    int temp = 0;
+    
+    //send temperature command
+    _tx_buf[0] = SI7013_READ_TEMP;
+    tempSensor.write(_address, (char*)_tx_buf, 1);
+    tempSensor.read(_address, (char*)_rx_buf, 2);
+    
+    /* Store raw temperature info */
+    temp = ((uint32_t)_rx_buf[0] << 8) + (_rx_buf[1] & 0xFC);
+    /* Convert to milli-degC */
+    temp = (((_tData) * 21965L) >> 13) - 46850;
+    
+    return temp;
+} 
+
+int main() {
+    //Enable the sensor
+    SENS_EN = 1;
+    
+    //Check if the sensor is present
+    _tx_buf[0] = SI7013_READ_ID2_1;
+    _tx_buf[1] = SI7013_READ_ID2_2;
+    
+    _address = SI7021_ADDR; //TODO: update if we use another sensor
+    
+    tempSensor.write(_address, (char*)_tx_buf, 2);
+    tempSensor.read(_address, (char*)_rx_buf, 8);
+    //Check ID byte
+    if(_rx_buf[0] != SI7021_DEVICE_ID) {
+        printf("No sensor present!\r\n");
+        while(1);
+    }
+    
+    while(1) {
+        wait(1);
+        _tData = readTemperature();
+        printf("Temperature: %d,%3d\r\n", _tData / 1000, _tData % 1000);
+    }
+}
\ No newline at end of file