pressure

Dependents:   xtrinsic_sensors

Files at this revision

API Documentation at this revision

Comitter:
otis22894
Date:
Sun Dec 11 21:12:09 2016 +0000
Commit message:
First commit

Changed in this revision

MPL3115.cpp Show annotated file Show diff for this revision Revisions of this file
MPL3115.h Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r 01659d3a8c37 MPL3115.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MPL3115.cpp	Sun Dec 11 21:12:09 2016 +0000
@@ -0,0 +1,90 @@
+ /* Copyright (c) 2015 NXP Semiconductors. MIT License
+*
+* 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.
+*/
+
+#include "MPL3115.h"
+#include "mbed.h"
+#define REG_PRESSURE_MSB    0x01
+
+MPL3115::MPL3115(PinName sda, PinName scl, int addr) : MPL3115_i2c(sda,scl), m_addr(addr)
+ {
+       
+ }
+    
+ void MPL3115::config(void)
+ {
+   char d[2]; 
+   d[0] = MPL3115_CTRL_REG1;                     //Puts device in Standby mode
+   d[1] = 0x00; 
+   MPL3115_i2c.write(MPL3115_I2C_ADDRESS, d,2);   
+          
+   
+   d[0] = MPL3115_CTRL_REG1;                     //Puts device in Active mode and in altimeter mode
+   d[1] = 0x81;
+   MPL3115_i2c.write(MPL3115_I2C_ADDRESS, d, 2);   
+      
+ }
+ 
+
+ float MPL3115::getPressure(void)
+{
+    float a;
+    
+    a = getPressure(REG_PRESSURE_MSB);
+    return a;
+}
+ 
+ float MPL3115::getPressure(unsigned char reg)
+{
+    unsigned char dt[3];
+    unsigned int prs;
+    int tmp;
+    float fprs;
+    
+    /*
+    * dt[0] = Bits 12-19 of 20-bit real-time Pressure sample. (b7-b0)
+    * dt[1] = Bits 4-11 of 20-bit real-time Pressure sample. (b7-b0)
+    * dt[2] = Bits 0-3 of 20-bit real-time Pressure sample (b7-b4)
+    */
+    readRegs( reg, &dt[0], 3);
+    prs = ((dt[0]<<10) | (dt[1]<<2) | (dt[2]>>6));
+    //
+    if ( dt[0] > 0x7f) {
+        // negative number
+        if ( dt[0] & 0x80)
+            prs |= 0xFFFC0000;      
+        else
+            prs |= 0xFFFE0000;
+        tmp = ~prs + 1;             // make the complemets. At this point all the bits are inverted.
+        fprs = (float)tmp * -1.0f;  
+    } else {
+        fprs = (float)prs * 1.0f;
+    }
+ 
+    if ( dt[2] & 0x10)              
+        fprs += 0.25f;             
+    if ( dt[2] & 0x20)
+        fprs += 0.5f;
+        
+    return fprs;
+}
+ void MPL3115::readRegs(int addr, uint8_t * data, int len) {
+    char t[1] = {addr};
+    MPL3115_i2c.write(m_addr, t, 1, true);
+    MPL3115_i2c.read(m_addr, (char *)data, len);
+}
+ 
\ No newline at end of file
diff -r 000000000000 -r 01659d3a8c37 MPL3115.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MPL3115.h	Sun Dec 11 21:12:09 2016 +0000
@@ -0,0 +1,49 @@
+ /* Copyright (c) 2015 NXP Semiconductors. MIT License
+*
+* 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.
+*/
+
+#ifndef MPL3115_H
+#define MPL3115_H
+#include "mbed.h"
+
+#define MPL3115_I2C_ADDRESS (0x60<<1)
+
+#define MPL3115_STATUS 0x00
+#define MPL3115_WHO_AM_I 0x0C
+#define MPL3115_CTRL_REG1 0x26
+#define MPL3115_CTRL_REG2 0x27
+#define MPL3115_WHO_AM_I_VALUE 0xC4
+
+class MPL3115
+{
+    public:
+    
+    MPL3115(PinName sda, PinName scl, int addr);
+      
+    void config(void);
+            
+    float getPressure(void);
+    float getPressure(unsigned char reg);
+    void readRegs(int addr, uint8_t * data, int len);
+
+    private:
+    I2C MPL3115_i2c;
+    int m_addr;
+    
+};
+
+#endif
\ No newline at end of file