Diff: main.cpp

Revision:

1:f4a1942b4486

Parent:

0:062188c0bb61

--- a/main.cpp	Thu Aug 10 13:25:37 2017 +0000
+++ b/main.cpp	Wed Sep 13 13:36:04 2017 +0000
@@ -1,143 +1,5 @@
 #include "mbed.h"
-
-/**
- * A simple library for SHT21 humidity and temperature sensor.
- * Based on the Arduino library.
- */
-
-class SHT21 {
-public:
-    SHT21(PinName sda, PinName scl, char addr = (0x40 << 1));
-    SHT21(I2C &i2c,  char addr = (0x40 << 1));
-    
-    float temperature();
-    float humidity();
-    
-    void reset();
-    void serialNumber(uint8_t *serialNumber);
-    
-    ~SHT21();
-private:
-    enum commands {
-        TRIGGER_T_MEASUREMENT_HM    = 0xE3,
-        TRIGGER_RH_MEASUREMENT_HM   = 0xE5,
-        TRIGGER_T_MEASUREMENT_NHM   = 0xF3,
-        TRIGGER_RH_MEASUREMENT_NHM  = 0xF5,
-        USER_REGISTER_W             = 0xE6,
-        USER_REGISTER_R             = 0xE7,
-        SOFT_RESET                  = 0xFE
-    };
-
-    static const uint16_t POLYNOMIAL;
-
-    char addr_;
-    I2C *pi2c_;
-    I2C &i2c_;
-    
-    uint16_t readRaw(uint8_t cmd);
-    static bool crcChecksum(const uint8_t *data, uint8_t sz, uint8_t checksum);
-};
-
-const uint16_t SHT21::POLYNOMIAL = 0x131;
-
-SHT21::SHT21(PinName sda, PinName scl, char addr) :
-    addr_(addr),
-    pi2c_(new I2C(sda, scl)),
-    i2c_(*pi2c_) {
-}
-
-SHT21::SHT21(I2C &i2c, char addr) :
-    addr_(addr),
-    pi2c_(NULL),
-    i2c_(i2c) {
-}
-
-float SHT21::temperature() {
-    uint16_t r = readRaw(TRIGGER_T_MEASUREMENT_HM);
-    r &= ~0x0003;
-    return (-46.85 + 175.72/65536 * (float) r);
-}
-
-float SHT21::humidity() {
-    uint16_t r = readRaw(TRIGGER_RH_MEASUREMENT_HM);
-    r &= ~0x0003;
-    return (-6.0 + 125.0/65536 * (float) r);
-}
-
-void SHT21::reset() {
-    uint8_t pcmd [] = { SOFT_RESET };
-    i2c_.write(addr_, (const char *) pcmd, 1);
-    wait_ms(15);
-}
-
-void SHT21::serialNumber(uint8_t *serialNumber) {
-    uint8_t data[8];
-    uint8_t pcmd0[2] = { 0xFA, 0x0F };
-    uint8_t pcmd1[2] = { 0xFC, 0xC9 };
-    uint8_t i = 0;
-    i2c_.write(addr_, (const char *) pcmd0, 2);
-    i2c_.read(addr_, (char *) data, 8);
-    
-    serialNumber[5] = data[i++];
-    i++;
-    serialNumber[4] = data[i++];
-    i++;
-    serialNumber[3] = data[i++];
-    i++;
-    serialNumber[2] = data[i++];
-    i = 0;
-    
-    i2c_.write(addr_, (const char *) pcmd1, 2);
-    i2c_.read(addr_, (char *) data, 6);
-    
-    serialNumber[1] = data[i++];
-    serialNumber[0] = data[i++];
-    i++;
-    serialNumber[7] = data[i++];
-    serialNumber[8] = data[i++];
-    i = 0;
-}
-
-SHT21::~SHT21() {
-    if (pi2c_) delete pi2c_;
-}
-
-uint16_t SHT21::readRaw(uint8_t cmd) {
-    uint8_t checksum;
-    uint8_t data[2];
-    uint16_t result;
-
-    uint8_t pcmd [] = { cmd };
-
-    i2c_.write(addr_, (const char *) pcmd, 1);
-    i2c_.read(addr_, (char *) data, 2);
-    i2c_.read(addr_, (char *) &checksum, 1);
-
-    result =    data[0] << 8;
-    result +=   data[1];
-
-    if (crcChecksum(data, 2, checksum)) {
-        reset();
-        return 1;
-    }
-    return result;
-}
-
-bool SHT21::crcChecksum(const uint8_t *data, uint8_t sz, uint8_t checksum) {
-    uint8_t crc = 0;
-    
-    for (uint8_t i = 0; i < sz; ++i) {
-        crc ^= data[i];
-        for (uint8_t j /* bit index */ = 8; j > 0; --j) {
-            if (crc & 0x80)
-                crc = (crc << 1) ^ POLYNOMIAL;
-            else
-                crc = (crc << 1);
-        }
-    }
-    
-    return crc == checksum;
-}
+#include "SHT21.hpp"
 
 SHT21 sht21(PB_9 /* I2C_SDA */, PB_8 /* I2C_SCL */);
 Serial pc(USBTX, USBRX);