Diff: PeripheralLayer/PeMod_SHT20.cpp

Revision:

0:3dac4f477e98

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PeripheralLayer/PeMod_SHT20.cpp	Wed Jul 08 17:50:18 2015 +0000
@@ -0,0 +1,49 @@
+#include "SysConfig.h"
+
+#define SHT20_ADDR          (0x40<<1)   //SHT20 address
+#define SHT20_CMD_TMP_NH    (0xF3)      //Non-hold temp trigger command
+#define SHT20_CMD_RH_NH     (0xF5)      //Non-hold temp trigger command
+
+#define i2c_sht20 i2c_sen
+//#define uart_db uart_pc
+
+int SHT20_Init(void)
+{
+    return 0;    
+}
+
+float SHT20_ReadTemp(void)
+{
+    char cmd = SHT20_CMD_TMP_NH, data[3]; 
+    float temp;
+    
+    i2c_sht20.write(SHT20_ADDR, &cmd, 1, 1);
+    wait_us(20);
+    i2c_sht20.stop();
+    
+    wait_ms(100);
+    i2c_sht20.read(SHT20_ADDR, data, 3);
+    #if defined uart_db
+    uart_db.printf("\n\rSHT20 return 0x%02X 0x%02X 0x%02X\n\r", data[0], data[1], data[2]);
+    #endif
+    temp = (256.0 * data[0] + data[1]) * 175.72 / (0x1 << 16) - 46.85;
+    return temp;
+}
+
+float SHT20_ReadRh(void)
+{
+    char cmd = SHT20_CMD_RH_NH, data[3]; 
+    float rh;
+    
+    i2c_sht20.write(SHT20_ADDR, &cmd, 1, 1);
+    wait_us(20);
+    i2c_sht20.stop();
+    
+    wait_ms(100);
+    i2c_sht20.read(SHT20_ADDR, data, 3);
+    #if defined uart_db
+    uart_db.printf("\n\rSHT20 return 0x%02X 0x%02X 0x%02X\n\r", data[0], data[1], data[2]);
+    #endif
+    rh = (256.0 * data[0] + data[1]) * 125 / (0x1 << 16) - 6;
+    return rh;    
+}
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