Diff: Si7021.h

Revision:

12:45c2bb8231bf

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Si7021.h	Sun Sep 24 06:18:49 2017 +0000
@@ -0,0 +1,72 @@
+#ifndef SI7021_H
+#define SI7021_H
+ 
+#include "mbed.h"
+ 
+/** Si7012 Read Temperature Command */
+#define READ_TEMP        0xE0 /* Read previous T data from RH measurement command*/
+/** Si7012 Read RH Command */
+#define READ_RH          0xE5 /* Perform RH (and T) measurement. */
+ 
+/** Si7012 Read ID */
+#define READ_ID1_1       0xFA
+#define READ_ID1_2       0x0F
+#define READ_ID2_1       0xFC
+#define READ_ID2_2       0xC9
+ 
+/** Si7012 Read Firmware Revision */
+#define READ_FWREV_1     0x84
+#define READ_FWREV_2     0xB8
+ 
+/** I2C device address for Si7021 */
+#define ADDR    0x80
+ 
+/** I2C device frequency for Si7021 */
+#define FREQ    100000
+ 
+/** Device ID value for Si7021 */
+#define DEVICE_ID 0x15
+ 
+class Si7021
+{
+public:
+    Si7021(PinName sda, PinName scl);
+    ~Si7021();
+    
+    /*
+     * Get last measured temperature data
+     * return: int32_t = temperature in millidegrees centigrade
+     */
+    int32_t get_temperature();
+ 
+    /*
+     * Get last measured relative humidity data
+     * return: uint32_t = relative humidity value in milli-percent
+     */
+    uint32_t get_humidity();
+    
+    /*
+     * Perform measurement.
+     * Asynchronous callback can be provided (type void (*)(void)).
+     * return: 0 if successful, else one of the defined error codes.
+     */
+    bool measure();
+    
+    /*
+     * Check if the sensor is active and responding. This will update the get_active value.
+     * Asynchronous callback can be provided (type void (*)(void)).
+     * return: 0 if successful, else one of the defined error codes.
+     */
+    bool check();
+    
+private:
+    I2C i2c;
+    
+    uint8_t  rx_buff[8];
+    uint8_t  tx_buff[2];
+ 
+    uint32_t rhData;
+    int32_t  tData;
+};
+ 
+#endif
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