Diff: MS5803/MS5803.cpp

Revision:

0:f0809a7877ff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MS5803/MS5803.cpp	Sat Apr 07 14:18:42 2012 +0000
@@ -0,0 +1,106 @@
+/*
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+  * Barometer Sensor (Altimeter) MS5803-01BA of MEAS Switzerland     (www.meas-spec.com).
+  * The driver uses I2C mode (sensor PS pin low).
+  * Other types of MEAS are compatible but not tested.
+  * Written by Raig Kaufer distribute freely!
+ */
+
+#include <stdlib.h>
+#include "MS5803.h"
+
+
+/*
+ * Sensor operating function according data sheet
+ */
+
+/* Send soft reset to the sensor */
+void MS5803::MS5803Reset(void) {
+    /* transmit out 1 byte reset command */
+    ms5803_tx_data[0] = ms5803_reset;
+    if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
+    wait_ms(20);
+}
+
+/* read the sensor calibration data from rom */
+void MS5803::MS5803ReadProm(void) {
+    uint8_t i,j;
+    for (i=0; i<8; i++) {
+        j = i;
+        ms5803_tx_data[0] = ms5803_PROMread + (j<<1);
+        if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
+        if ( i2c.read( device_address,  ms5803_rx_data, 2 ) );
+        C[i]   = ms5803_rx_data[1] + (ms5803_rx_data[0]<<8);
+    }
+}
+
+/* Start the sensor pressure conversion */
+void MS5803::MS5803ConvertD1(void) {
+    ms5803_tx_data[0] = ms5803_convD1;
+    if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
+}
+
+/* Start the sensor temperature conversion */
+void MS5803:: MS5803ConvertD2(void) {
+    ms5803_tx_data[0] = ms5803_convD2;
+    if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
+}
+
+/* Read the privious started conversion results */
+int32_t MS5803::MS5803ReadADC(void) {
+    int32_t adc;
+    wait_ms(150);
+    ms5803_tx_data[0] = ms5803_ADCread;
+    if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
+    if ( i2c.read( device_address,  ms5803_rx_data, 3 ) );
+    adc = ms5803_rx_data[2] + (ms5803_rx_data[1]<<8) + (ms5803_rx_data[0]<<16);
+    return (adc);
+}
+
+/* return the results */
+float MS5803::MS5803_Pressure (void) {
+    return P_MS5803;
+}
+float MS5803::MS5803_Temperature (void) {
+    return T_MS5803;
+}
+
+/* Sensor reading and calculation prcedure */
+void MS5803::Barometer_MS5803(void) {
+    int32_t dT, temp;
+    int64_t OFF, SENS, press;
+
+    MS5803Reset();                 // reset the sensor
+    MS5803ReadProm();             // read the calibration values
+    MS5803ConvertD1();             // start pressure convertion
+    D1 = MS5803ReadADC();        // read the pressure value
+    MS5803ConvertD2();             // start temperature convertion
+    D2 = MS5803ReadADC();         // read the temperature value
+
+    /* calculation according MS5803-01BA data sheet DA5803-01BA_006 */
+    dT       = D2 - (C[5]* 256);
+    OFF      = (int64_t)C[2] * (1<<16) + ((int64_t)dT * (int64_t)C[4]) / (1<<7);
+    SENS     = (int64_t)C[1] * (1<<15) + ((int64_t)dT * (int64_t)C[3]) / (1<<8);
+
+    temp     = 2000 + (dT * C[6]) / (1<<23);
+    T_MS5803 = (float) temp / 100.0f;                 // result of temperature in deg C in this var
+    press    = (((int64_t)D1 * SENS) / (1<<21) - OFF) / (1<<15);
+    P_MS5803 = (float) press / 100.0f;                 // result of pressure in mBar in this var
+}