Bruno Alfano
A library to use Honeywell pressure sensors from HSC series with SPI connection. For calibration scale and pressure range you have to set the declarations inside the hsc_spi.h file - Default values are for 10-90% calibration and 1.6bar absolute sensor
Revision 0:0056857990b9, committed 2014-02-16
- Comitter:
- brunoalfano
- Date:
- Sun Feb 16 18:30:04 2014 +0000
- Commit message:
- Library for Honeywell HSC pressure sensor via SPI
Changed in this revision
| hsc_spi.cpp | Show annotated file Show diff for this revision Revisions of this file |
| hsc_spi.h | Show annotated file Show diff for this revision Revisions of this file |
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hsc_spi.cpp Sun Feb 16 18:30:04 2014 +0000
@@ -0,0 +1,41 @@
+#include <mbed.h>
+#include "hsc_spi.h"
+
+hsc_spi::hsc_spi(SPI& _spi, PinName _ncs) : spi(_spi), ncs(_ncs) {}
+
+void hsc_spi::spi_init(){
+ spi.format(16,0);
+ }
+
+float hsc_spi::read_temp() {
+ unsigned int response;
+ float temperature;
+ select();
+ response=spi.write(0x0000);
+ response=spi.write(0x0000);
+ response=response/32;
+ temperature=response*200.0/2047.0 - 50.0;
+ deselect();
+ return temperature;
+}
+
+float hsc_spi::read_press() {
+ unsigned int response;
+ float pressure;
+ select();
+ response=spi.write(0x0000);
+ pressure=1.0*(response - OUTPUT_MIN)*(P_MAX - P_MIN)/(OUTPUT_MAX - OUTPUT_MIN) + P_MIN;
+ deselect();
+ return pressure;
+}
+
+void hsc_spi::select() {
+ spi_init();
+ //Set CS low to start transmission (interrupts conversion)
+ ncs = 0;
+}
+
+void hsc_spi::deselect() {
+ //Set CS high to stop transmission (restarts conversion)
+ ncs = 1;
+}
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hsc_spi.h Sun Feb 16 18:30:04 2014 +0000
@@ -0,0 +1,33 @@
+#ifndef hsc_spi_h
+#define hsc_spi_h
+
+#include "mbed.h"
+
+#define OUTPUT_MAX 0x399A
+#define OUTPUT_MIN 0x0666
+#define P_MAX 1600
+#define P_MIN 0
+
+class hsc_spi
+{
+ SPI& spi;
+ DigitalOut ncs;
+ Timer pollTimer;
+ public:
+
+ hsc_spi(SPI& _spi, PinName _ncs);
+ //void initialise(int out_max,int out_min,int pmax, int pmin);
+ float read_press();
+ float read_temp();
+ void spi_init();
+ void select();
+ void deselect();
+
+ private:
+ PinName _CS_pin;
+ PinName _SO_pin;
+ PinName _SCK_pin;
+ float _error;
+};
+
+#endif