Revision 0:55ea30b5de1e, committed 2011-06-17

Comitter:

joosttromp

Date:

Fri Jun 17 12:37:27 2011 +0000

Commit message:

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SCP1000.cpp	Fri Jun 17 12:37:27 2011 +0000
@@ -0,0 +1,85 @@
+/**
+ * @section LICENSE
+ * This program is free software; you can redistribute it and/or modify 
+ * it under the terms of the GNU General Public License as published by 
+ * the Free Software Foundation; either version 2 of the License, or 
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful, but 
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
+ * for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along 
+ * with this program; if not, write to the Free Software Foundation, Inc., 
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * @section DESCRIPTION
+ * Library to interface with the SCP1000 pressure and temperature sensor.
+ */
+
+#include "SCP1000.h"
+
+SCP1000::SCP1000(PinName mosi, PinName miso, PinName sclk, PinName cs)
+    : m_spi(mosi, miso, sclk)
+    , m_cs(cs) {
+    m_cs=1;
+    m_spi.frequency(500000); // the fastest of the sensor
+    m_spi.format(8, 0); // duda son dos palabras de 8 bits? 
+    wait(0.5);
+    //------------------------------------------------
+    // pc.printf("RESET\r\n");
+    write_register(0x06,0x01);
+    wait(0.5);
+
+    // pc.printf("Initialize High Resolution Constant Reading Mode\r\n");
+    write_register(0x03,0x0A);
+    wait(0.5);
+}
+
+unsigned long SCP1000::readPressure() {
+    unsigned long pressure_msb = read_register(PRESSURE);
+    pressure_msb &= 0x07;
+    unsigned long pressure_lsb = read_register16(PRESSURE_LSB);
+    unsigned long pressure = ((pressure_msb<<16)| pressure_lsb);
+    pressure /= 4;
+    
+    return pressure;
+}
+
+float SCP1000::readTemperature() {
+    float temp_in = read_register16(TEMP);
+    temp_in /= 20;
+    return temp_in;
+}
+
+ char SCP1000::read_register(char register_name) {
+    register_name <<=2;
+    register_name &= 0xFC;
+    m_cs=0; //Select SPI device
+    m_spi.write(register_name); //Send register location
+    char register_value=m_spi.write(0x00);
+    m_cs=1;
+    return register_value;  
+}
+
+void SCP1000::write_register(char register_name, char register_value) {
+    register_name <<= 2;
+    register_name |= 0x02; //le estamos diciendo que escriba
+    m_cs=0; //Select SPI device
+    m_spi.write(register_name); //Send register location
+    m_spi.write(register_value); //Send value to record into register
+    m_cs=1;
+}
+
+float SCP1000::read_register16(char register_name) {   
+    register_name <<= 2;
+    register_name &= 0xFC; //Read command
+    m_cs=0; //Select SPI Device
+    m_spi.write(register_name); //Write byte to device
+    int in_byte1 = m_spi.write(0x00);    
+    int in_byte2 = m_spi.write(0x00);
+    m_cs=1;
+    float in_word= (in_byte1<<=8) | (in_byte2);   
+    return(in_word);
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SCP1000.h	Fri Jun 17 12:37:27 2011 +0000
@@ -0,0 +1,71 @@
+/**
+ * @section LICENSE
+ * This program is free software; you can redistribute it and/or modify 
+ * it under the terms of the GNU General Public License as published by 
+ * the Free Software Foundation; either version 2 of the License, or 
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful, but 
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
+ * for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along 
+ * with this program; if not, write to the Free Software Foundation, Inc., 
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * @section DESCRIPTION
+ * Library to interface with the SCP1000 pressure and temperature sensor.
+ */
+
+#ifndef _SCP1000_H
+#define _SCP1000_H
+
+#include "mbed.h"
+
+/**
+ * Class to interface with the SCP1000 pressure and temperature sensor.
+ */
+class SCP1000 {
+    public:
+        /**
+         * Constructor.
+         *
+         * @param mosi SPI MOSI pin
+         * @param miso SPI MISO pin
+         * @param sclk SPI SCLK pin
+         * @param cs Chip select pin
+         */
+        SCP1000(PinName mosi, PinName miso, PinName sclk, PinName cs);
+        
+        ~SCP1000() { /* empty */ };
+        
+        /**
+         * Read the pressure.
+         *
+         * @returns The pressure in pascals.
+         */
+        unsigned long readPressure();
+        
+        /**
+         * Read the temperature.
+         *
+         * @returns The temperature in Celsius.
+         */
+        float readTemperature();
+        
+        
+    private:
+        static const char PRESSURE = 0x1F;   //Pressure 3 MSB
+        static const char PRESSURE_LSB = 0x20; //Pressure 16 LSB
+        static const char TEMP = 0x21;       //16 bit temp
+        SPI m_spi;
+        DigitalOut m_cs;
+        
+        char read_register(char register_name);
+        void write_register(char register_name, char register_value);
+        float read_register16(char register_name);
+
+};
+
+#endif // _SCP1000_H
\ No newline at end of file