LDC1000

Revision 0:90873b4e8330, committed 2015-04-05

Comitter:

vsluiter

Date:

Sun Apr 05 18:19:12 2015 +0000

Child:

1:a88df80e7664

Commit message:

Initial commit

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LDC1000.cpp	Sun Apr 05 18:19:12 2015 +0000
@@ -0,0 +1,92 @@
+/**
+* @file LDC1000.h
+* @brief this C++ file wcontains all required
+* functions to interface with Texas
+* Instruments' LDC1000.
+*
+* @author Victor Sluiter
+*
+* @date 2015-04-01
+*/
+
+#include "LDC1000.h"
+
+LDC1000::LDC1000(PinName mosi, PinName miso, PinName sck, PinName cs, float capacitor, float f_external, PinName clock_out) : _spiport(mosi,miso,sck,NC), _cs_pin(cs), _clock(clock_out)
+{
+    cap = capacitor;
+    _spiport.format(8,3);
+    _spiport.frequency(1E6);
+    _cs_pin.write(1);
+    setFrequency(f_external);
+    setResponseTime(LDC_RESPONSE_384);
+    mode(LDC_MODE_ACTIVE);
+}
+
+void LDC1000::setOutputPower(LDC_AMPLITUDE amplitude)
+{
+    uint8_t buffer;
+    _amplitude  = amplitude;
+    readSPI(&buffer, 0x04);
+    buffer &= 0xE7; //clear amplitude bits
+    buffer |= (amplitude<<3) & 0xE7;
+    writeSPI(&buffer,0x04);
+
+}
+
+void LDC1000::setResponseTime(LDC_RESPONSE responsetime)
+{
+    uint8_t buffer;
+    _responsetime = responsetime;
+    readSPI(&buffer, 0x04);
+    buffer &= 0xF8; //clear responsetime bits
+    buffer |= responsetime & 0xF8;
+    writeSPI(&buffer,0x04);
+}
+
+void LDC1000::setFrequency(float frequency)
+{
+    _frequency = frequency;
+    _clock.period(1.0/frequency);
+}
+
+float LDC1000::getInductance()
+{
+    uint16_t resp[] = {192, 384, 768, 1536, 3072, 6144};
+    _raw_l = readRawCounts();
+    _fsensor = (_frequency/(_raw_l*3.0))*resp[(uint8_t)(_responsetime)];
+    return 1/(cap*pow(2*PI*_fsensor,2));
+};
+
+uint32_t LDC1000::readRawCounts(void)
+{
+    union
+    {
+        uint8_t buf[4];
+        uint32_t value;
+    } val;
+    val.value = 0;
+    readSPI(val.buf,0x23,3);
+    return val.value;
+}
+
+void LDC1000::readSPI(uint8_t *data, uint8_t address, uint8_t num_bytes)
+{
+    _cs_pin.write(0);
+    _spiport.write(address | 0x80); //read flag 
+    for(int i=0; i < num_bytes ; i++)
+    {
+        _spiport.write(data[i]);
+    }
+    _cs_pin.write(1);
+}
+
+void LDC1000::writeSPI(uint8_t *data, uint8_t address, uint8_t num_bytes)
+{
+    _cs_pin.write(0);
+    _spiport.write(address); 
+    for(int i=0; i < num_bytes ; i++)
+    {
+        *data = _spiport.write(0xFF);
+    }
+    _cs_pin.write(1);
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LDC1000.h	Sun Apr 05 18:19:12 2015 +0000
@@ -0,0 +1,109 @@
+#ifndef _LDC1000_H_
+#define _LDC1000_H_
+
+/**
+* @file LDC1000.h
+* @brief this header file will contain all required
+* definitions for the functions to interface with Texas
+* Instruments' LDC1000.
+*
+* @author Victor Sluiter
+*
+* @date 2015-04-01
+*/
+
+#include "mbed.h"
+
+#ifndef PI
+#define PI 3.14
+#endif
+
+typedef enum {  LDC_RESPONSE_192=2,\
+                LDC_RESPONSE_384,  \
+                LDC_RESPONSE_768,  \
+                LDC_RESPONSE_1536, \
+                LDC_RESPONSE_3072, \
+                LDC_RESPONSE_6144} LDC_RESPONSE;
+
+typedef enum {  LDC_AMPLITUDE_1V=0,\
+                LDC_AMPLITUDE_2V,  \
+                LDC_AMPLITUDE_4V} LDC_AMPLITUDE;
+
+typedef enum { LDC_MODE_STANDBY = 0; LDC_MODE_ACTIVE = 1} LDC_MODE;
+
+
+/**
+* Class for the LDC1000.
+* @author Victor Sluiter
+* @date 2015-04-01
+*/
+class LDC1000
+{
+    public:
+    /**
+    * @brief Create a new Class to interface to an LDC1000
+    **/
+    LDC1000(PinName mosi, PinName miso, PinName sck, PinName cs, float capacitor, float f_external, PinName clock_out=NC);
+    /**
+    * @brief Set power mode.
+    * The constructor sets the LDC1000 in Active mode.
+    * @param mode choose from LDC_MODE_ACTIVE or LDC_MODE STANDBY
+    **/
+    void mode(LDC_MODE mode){writeSPI(&mode, 0x0B);};
+    /**
+    * @brief get the calculated inductance value
+    **/
+    float getInductance(void);
+    /**
+    * @brief Set the value of the external capacitor
+    * This is needed for the calculation of the inductance.
+    **/
+    void  setCapacitor(float c){cap = c;};
+    /**
+    * @brief set the value of the external clock
+    * If PWMout is used to generate a clock signal, this will update the output frequency.s
+    **/
+    void  setFrequency(float frequency);
+    /**
+    * @brief Read the raw 24-bit inductance value.
+    * This is needed for the calculation of the inductance.
+    **/
+    uint32_t readRawL(void){_raw_l = readRawCounts(); return _raw_l;};
+    /**
+    * @brief Set the Response Time parameters. 
+    * @param responsetime 
+    * Larger value increases accuracy, but slows down the output data rate. Choose one of these values:
+    * - LDC_RESPONSE_192
+    * - LDC_RESPONSE_384
+    * - LDC_RESPONSE_768
+    * - LDC_RESPONSE_1536
+    * - LDC_RESPONSE_3072
+    * - LDC_RESPONSE_6144
+    **/
+    void setResponseTime(LDC_RESPONSE responsetime);
+    /**
+    * @brief Set the oscilation amplitude.
+    * Use one of these values:
+    * - LDC_AMPLITUDE_1V
+    * - LDC_AMPLITUDE_2V
+    * - LDC_AMPLITUDE_4V
+    **/
+    enable power
+    void setOutputPower(LDC_AMPLITUDE amplitude);
+    private:
+    void readSPI(uint8_t *data, uint8_t address, uint8_t num_bytes = 1);
+    void writeSPI(uint8_t *data, uint8_t address, uint8_t num_bytes = 1);
+    uint32_t readRawCounts(void);
+    LDC_RESPONSE _responsetime;
+    LDC_AMPLITUDE _amplitude;
+    float _fsensor;
+    float _inductance;
+    float _frequency; //frequency of external clock
+    float cap;    
+    uint32_t _raw_l;
+    SPI _spiport;
+    DigitalOut _cs_pin;
+    PwmOut _clock;
+};
+
+#endif
\ No newline at end of file