Bob Giesberts / LDC1101

Library to communicate with LDC1101

Dependents:   Inductive_Sensor Inductive_Sensor_Jasper Inductive_Sensor_3

Fork of LDC1000 by First Last

LDC1101.h@19:e205ab9142d8, 2015-12-16 (annotated)

Committer:
bobgiesberts
Date:
Wed Dec 16 16:25:33 2015 +0000
Revision:
19:e205ab9142d8
Parent:
18:fc9bb81a631f
Child:
20:8e1b1efdbb49
Tweaking the internal settings (RP_Min, Responsetime, divider, etc.) to find the optimal configuration (= highest resolution, highest accuracy, linearity, etc.).

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bobgiesberts 16:07d0e43c2d12 1 #ifndef _LDC1101_H_
bobgiesberts 16:07d0e43c2d12 2 #define _LDC1101_H_
bobgiesberts 16:07d0e43c2d12 3
bobgiesberts 16:07d0e43c2d12 4 #include "FastPWM.h"
bobgiesberts 16:07d0e43c2d12 5 /**
bobgiesberts 16:07d0e43c2d12 6 * @file LDC1101.h
bobgiesberts 16:07d0e43c2d12 7 * @brief this header file will contain all required
bobgiesberts 16:07d0e43c2d12 8 * definitions for the functions to interface with Texas
bobgiesberts 16:07d0e43c2d12 9 * Instruments' LDC1101.
bobgiesberts 16:07d0e43c2d12 10 *
bobgiesberts 16:07d0e43c2d12 11 * @author Victor Sluiter
bobgiesberts 16:07d0e43c2d12 12 *
bobgiesberts 16:07d0e43c2d12 13 * @date 2015-12-09
bobgiesberts 16:07d0e43c2d12 14 */
bobgiesberts 16:07d0e43c2d12 15
bobgiesberts 16:07d0e43c2d12 16 #include "mbed.h"
bobgiesberts 16:07d0e43c2d12 17
bobgiesberts 16:07d0e43c2d12 18 #ifndef PI
bobgiesberts 16:07d0e43c2d12 19 #define PI 3.14
bobgiesberts 16:07d0e43c2d12 20 #endif
bobgiesberts 16:07d0e43c2d12 21
bobgiesberts 16:07d0e43c2d12 22 typedef enum { LDC_RESPONSE_192 = 2, \
bobgiesberts 16:07d0e43c2d12 23 LDC_RESPONSE_384 = 3, \
bobgiesberts 19:e205ab9142d8 24 LDC_RESPONSE_768 = 4, \
bobgiesberts 16:07d0e43c2d12 25 LDC_RESPONSE_1536= 5, \
bobgiesberts 16:07d0e43c2d12 26 LDC_RESPONSE_3072= 6, \
bobgiesberts 16:07d0e43c2d12 27 LDC_RESPONSE_6144= 7} LDC_RESPONSE;
bobgiesberts 16:07d0e43c2d12 28
bobgiesberts 19:e205ab9142d8 29 typedef enum { LDC_MODE_ACTIVE = 0, \
bobgiesberts 19:e205ab9142d8 30 LDC_MODE_STANDBY = 1, \
bobgiesberts 16:07d0e43c2d12 31 LDC_MODE_SHUTDOWN = 2} LDC_MODE;
bobgiesberts 16:07d0e43c2d12 32
bobgiesberts 17:a5cf2b4bec13 33 typedef enum { DIVIDER_1 = 0, \
bobgiesberts 17:a5cf2b4bec13 34 DIVIDER_2 = 1, \
bobgiesberts 17:a5cf2b4bec13 35 DIVIDER_4 = 2, \
bobgiesberts 17:a5cf2b4bec13 36 DIVIDER_8 = 3} DIVIDER;
bobgiesberts 17:a5cf2b4bec13 37
bobgiesberts 19:e205ab9142d8 38 typedef enum { RPMIN_96 = 0, \
bobgiesberts 19:e205ab9142d8 39 RPMIN_48 = 1, \
bobgiesberts 19:e205ab9142d8 40 RPMIN_24 = 2, \
bobgiesberts 19:e205ab9142d8 41 RPMIN_12 = 3, \
bobgiesberts 19:e205ab9142d8 42 RPMIN_6 = 4, \
bobgiesberts 19:e205ab9142d8 43 RPMIN_3 = 5, \
bobgiesberts 19:e205ab9142d8 44 RPMIN_1 = 6, \
bobgiesberts 19:e205ab9142d8 45 RPMIN_0 = 7} RPMIN;
bobgiesberts 17:a5cf2b4bec13 46
bobgiesberts 16:07d0e43c2d12 47 /**
bobgiesberts 16:07d0e43c2d12 48 * Class for the LDC1101.
bobgiesberts 16:07d0e43c2d12 49 * @author Victor Sluiter
bobgiesberts 16:07d0e43c2d12 50 * @date 2015-12-09
bobgiesberts 16:07d0e43c2d12 51 */
bobgiesberts 16:07d0e43c2d12 52 class LDC1101
bobgiesberts 16:07d0e43c2d12 53 {
bobgiesberts 16:07d0e43c2d12 54 public:
bobgiesberts 16:07d0e43c2d12 55 /**
bobgiesberts 16:07d0e43c2d12 56 * @brief Create a new Class to interface to an LDC1101
bobgiesberts 16:07d0e43c2d12 57 **/
bobgiesberts 18:fc9bb81a631f 58 LDC1101(PinName mosi, PinName miso, PinName sck, PinName cs, float capacitor, float f_CLKIN, PinName clock_out=NC);
bobgiesberts 16:07d0e43c2d12 59
bobgiesberts 16:07d0e43c2d12 60 /**
bobgiesberts 16:07d0e43c2d12 61 * @brief Set power mode.
bobgiesberts 16:07d0e43c2d12 62 * The constructor sets the LDC1101 in Active mode.
bobgiesberts 16:07d0e43c2d12 63 * @param mode choose from LDC_MODE_ACTIVE, LDC_MODE STANDBY or LDC_MODE_SHUTDOWN
bobgiesberts 16:07d0e43c2d12 64 **/
bobgiesberts 19:e205ab9142d8 65 void func_mode(LDC_MODE mode) { writeSPI((uint8_t *)(&mode), 0x0B); };
bobgiesberts 16:07d0e43c2d12 66
bobgiesberts 16:07d0e43c2d12 67 /**
bobgiesberts 16:07d0e43c2d12 68 * @brief initial configurations
bobgiesberts 16:07d0e43c2d12 69 **/
bobgiesberts 16:07d0e43c2d12 70 void init(void);
bobgiesberts 16:07d0e43c2d12 71
bobgiesberts 16:07d0e43c2d12 72 /**
bobgiesberts 19:e205ab9142d8 73 * @brief initialises LHR mode
bobgiesberts 19:e205ab9142d8 74 * Also enables shutdown modus
bobgiesberts 19:e205ab9142d8 75 **/
bobgiesberts 19:e205ab9142d8 76 void setLHRmode(void)
bobgiesberts 19:e205ab9142d8 77 {
bobgiesberts 19:e205ab9142d8 78 writeSPIregister(0x05, 0x03); // ALT_CONFIG: 0000 0011 --> LHR modus + Shutdown enabled
bobgiesberts 19:e205ab9142d8 79 writeSPIregister(0x0C, 0x01); // D_CONFIG: Enables a function that can improve L measurements while disabling RP measurements
bobgiesberts 19:e205ab9142d8 80 };
bobgiesberts 19:e205ab9142d8 81
bobgiesberts 19:e205ab9142d8 82 /**
bobgiesberts 19:e205ab9142d8 83 * @brief Settings for RP
bobgiesberts 19:e205ab9142d8 84 * @param RPMAX_DIS [7]
bobgiesberts 19:e205ab9142d8 85 * 0 - not disabled: RP_MAX is driven
bobgiesberts 19:e205ab9142d8 86 * 1 - disabled: RP_MAX is ignored, current drive is off.
bobgiesberts 19:e205ab9142d8 87 * @param RPMIN [2:0]
bobgiesberts 19:e205ab9142d8 88 * pi * V_amp
bobgiesberts 19:e205ab9142d8 89 * R_p = -----------
bobgiesberts 19:e205ab9142d8 90 * 4 * I_drive
bobgiesberts 19:e205ab9142d8 91 * This setting can be calibrated with the target closest to the sensor: R_p(d = 0mm)
bobgiesberts 19:e205ab9142d8 92 * RPMIN < 0.8 x R_p(d = 0mm)
bobgiesberts 19:e205ab9142d8 93 * If R_p < 750 Ohm --> increase distance to target
bobgiesberts 19:e205ab9142d8 94 * - 000: RPMIN = 96 kOhm | I_drive = 4.7 uA
bobgiesberts 19:e205ab9142d8 95 * - 001: RPMIN = 48 kOhm | I_drive = 9.4 uA
bobgiesberts 19:e205ab9142d8 96 * - 010: RPMIN = 24 kOhm | I_drive = 18.7 uA
bobgiesberts 19:e205ab9142d8 97 * - 011: RPMIN = 12 kOhm | I_drive = 37.5 uA
bobgiesberts 19:e205ab9142d8 98 * - 100: RPMIN = 6 kOhm | I_drive = 75 uA
bobgiesberts 19:e205ab9142d8 99 * - 101: RPMIN = 3 kOhm | I_drive = 150 uA
bobgiesberts 19:e205ab9142d8 100 * - 110: RPMIN = 1.5 kOhm | I_drive = 300 uA
bobgiesberts 19:e205ab9142d8 101 * - 111: RPMIN = 0.75 kOhm | I_drive = 600 uA (default)
bobgiesberts 19:e205ab9142d8 102 **/
bobgiesberts 19:e205ab9142d8 103 void setRPsettings(bool RPMAX_DIS, RPMIN rpmin);
bobgiesberts 19:e205ab9142d8 104
bobgiesberts 19:e205ab9142d8 105 /**
bobgiesberts 17:a5cf2b4bec13 106 * @brief Sensor divider (p.26)
bobgiesberts 19:e205ab9142d8 107 * Sensor input divider (p.35)
bobgiesberts 19:e205ab9142d8 108 * Because f_CLKIN > 4*f_sensor is not realisable for higher frequencies, so there is a divider
bobgiesberts 19:e205ab9142d8 109 * f_CLKIN > 4 * f_sensor / SENSOR_DIV
bobgiesberts 17:a5cf2b4bec13 110 * @param div
bobgiesberts 17:a5cf2b4bec13 111 * - DIVIDER_1
bobgiesberts 17:a5cf2b4bec13 112 * - DIVIDER_2
bobgiesberts 17:a5cf2b4bec13 113 * - DIVIDER_4
bobgiesberts 17:a5cf2b4bec13 114 * - DIVIDER_8
bobgiesberts 17:a5cf2b4bec13 115 **/
bobgiesberts 17:a5cf2b4bec13 116 void setDivider(DIVIDER div);
bobgiesberts 19:e205ab9142d8 117
bobgiesberts 16:07d0e43c2d12 118 /**
bobgiesberts 19:e205ab9142d8 119 * @brief Set the Response Time parameters. Does not apply in LHR mode (p.17)
bobgiesberts 16:07d0e43c2d12 120 * @param responsetime
bobgiesberts 16:07d0e43c2d12 121 * Larger value increases accuracy, but slows down the output data rate. Choose one of these values:
bobgiesberts 16:07d0e43c2d12 122 * - LDC_RESPONSE_192
bobgiesberts 16:07d0e43c2d12 123 * - LDC_RESPONSE_384
bobgiesberts 16:07d0e43c2d12 124 * - LDC_RESPONSE_768
bobgiesberts 16:07d0e43c2d12 125 * - LDC_RESPONSE_1536
bobgiesberts 16:07d0e43c2d12 126 * - LDC_RESPONSE_3072
bobgiesberts 16:07d0e43c2d12 127 * - LDC_RESPONSE_6144
bobgiesberts 19:e205ab9142d8 128 * ResponseTime
bobgiesberts 19:e205ab9142d8 129 * t_conv (s) = ------------
bobgiesberts 19:e205ab9142d8 130 * 3 x f_sensor
bobgiesberts 16:07d0e43c2d12 131 **/
bobgiesberts 16:07d0e43c2d12 132 void setResponseTime(LDC_RESPONSE responsetime);
bobgiesberts 16:07d0e43c2d12 133
bobgiesberts 19:e205ab9142d8 134 /**
bobgiesberts 19:e205ab9142d8 135 * @brief Set the Reference Count parameter.
bobgiesberts 19:e205ab9142d8 136 * @param LHR_Count
bobgiesberts 19:e205ab9142d8 137 * For LHR mode, the conversion time is set by the reference count LHR_RCOUNT (0x30 & 0x31) (p.34)
bobgiesberts 19:e205ab9142d8 138 * The conversion time represents the number of clock cycles used to measure the sensor frequency.
bobgiesberts 19:e205ab9142d8 139 * Higher values for LHR_RCOUNT have a higher effective measurement resolution but a lower sample rate. (p.34)
bobgiesberts 19:e205ab9142d8 140 * The maximum setting (0xffff) is required for full resolution (p. 35)
bobgiesberts 19:e205ab9142d8 141 * 1) LHR_Count = 1/sample rate [kS/s] - 55/f_CLKIN
bobgiesberts 19:e205ab9142d8 142 * 2) The reference count value must be chosen to support the required number of effective bits (ENOB).
bobgiesberts 19:e205ab9142d8 143 * e.g. ENOB 13 bits --> minimum converstion time 2^13 = 8192 clock cycles required. 8192 = 0x2000 = RCOUNT.
bobgiesberts 19:e205ab9142d8 144 **/
bobgiesberts 19:e205ab9142d8 145 void setReferenceCount(uint16_t LHR_Count);
bobgiesberts 19:e205ab9142d8 146 /**
bobgiesberts 19:e205ab9142d8 147 * @brief Set the value of the external capacitor
bobgiesberts 19:e205ab9142d8 148 * This is needed for the calculation of the inductance.
bobgiesberts 19:e205ab9142d8 149 **/
bobgiesberts 19:e205ab9142d8 150 void setCapacitor(float c){_cap = c;};
bobgiesberts 19:e205ab9142d8 151 /**
bobgiesberts 19:e205ab9142d8 152 * @brief set the value of the external clock
bobgiesberts 19:e205ab9142d8 153 * If PWMout is used to generate a clock signal, this will update the output frequency.s
bobgiesberts 19:e205ab9142d8 154 **/
bobgiesberts 19:e205ab9142d8 155 void setFrequency(float frequency){_fCLKIN = frequency;};
bobgiesberts 19:e205ab9142d8 156
bobgiesberts 19:e205ab9142d8 157
bobgiesberts 19:e205ab9142d8 158 /**
bobgiesberts 19:e205ab9142d8 159 * @brief Read LHR_Data, the raw 24-bit inductance value.
bobgiesberts 19:e205ab9142d8 160 * This is needed for the calculation of the inductance.
bobgiesberts 19:e205ab9142d8 161 * It reads from addresses 0x38, 0x39 & 0x3A.
bobgiesberts 19:e205ab9142d8 162 **/
bobgiesberts 19:e205ab9142d8 163 uint32_t get_LHR_Data(void);
bobgiesberts 19:e205ab9142d8 164 /**
bobgiesberts 19:e205ab9142d8 165 * @brief get the calculated value for f_sensor
bobgiesberts 19:e205ab9142d8 166 **/
bobgiesberts 19:e205ab9142d8 167 float get_fsensor(void);
bobgiesberts 19:e205ab9142d8 168 /**
bobgiesberts 19:e205ab9142d8 169 * @brief get the calculated inductance value
bobgiesberts 19:e205ab9142d8 170 **/
bobgiesberts 19:e205ab9142d8 171 float get_Inductance(void);
bobgiesberts 19:e205ab9142d8 172 /**
bobgiesberts 19:e205ab9142d8 173 * @brief get the reference frequency (f_CLKIN)
bobgiesberts 19:e205ab9142d8 174 **/
bobgiesberts 19:e205ab9142d8 175 float get_fCLKIN(void);
bobgiesberts 19:e205ab9142d8 176 /**
bobgiesberts 19:e205ab9142d8 177 * @brief get the responsetime
bobgiesberts 19:e205ab9142d8 178 **/
bobgiesberts 19:e205ab9142d8 179 uint16_t get_responsetime(void);
bobgiesberts 19:e205ab9142d8 180 /**
bobgiesberts 19:e205ab9142d8 181 * @brief get RPmin
bobgiesberts 19:e205ab9142d8 182 **/
bobgiesberts 19:e205ab9142d8 183 float get_RPmin(void);
bobgiesberts 19:e205ab9142d8 184 /**
bobgiesberts 19:e205ab9142d8 185 * @brief get the reference count
bobgiesberts 19:e205ab9142d8 186 **/
bobgiesberts 19:e205ab9142d8 187 uint16_t get_Rcount(void);
bobgiesberts 19:e205ab9142d8 188 /**
bobgiesberts 19:e205ab9142d8 189 * @brief get the divider
bobgiesberts 19:e205ab9142d8 190 **/
bobgiesberts 19:e205ab9142d8 191 uint8_t get_divider(void);
bobgiesberts 19:e205ab9142d8 192 /**
bobgiesberts 19:e205ab9142d8 193 * @brief get the capacitance
bobgiesberts 19:e205ab9142d8 194 **/
bobgiesberts 19:e205ab9142d8 195 float get_cap(void);
bobgiesberts 19:e205ab9142d8 196 /**
bobgiesberts 19:e205ab9142d8 197 * @brief get the quality
bobgiesberts 19:e205ab9142d8 198 **/
bobgiesberts 19:e205ab9142d8 199 float get_Q(void);
bobgiesberts 19:e205ab9142d8 200
bobgiesberts 19:e205ab9142d8 201
bobgiesberts 19:e205ab9142d8 202
bobgiesberts 19:e205ab9142d8 203
bobgiesberts 19:e205ab9142d8 204
bobgiesberts 19:e205ab9142d8 205
bobgiesberts 16:07d0e43c2d12 206 private:
bobgiesberts 16:07d0e43c2d12 207 void readSPI(uint8_t *data, uint8_t address, uint8_t num_bytes = 1);
bobgiesberts 16:07d0e43c2d12 208 void writeSPI(uint8_t *data, uint8_t address, uint8_t num_bytes = 1);
bobgiesberts 16:07d0e43c2d12 209 void writeSPIregister(uint8_t reg, uint8_t value){writeSPI(&value,reg);}; // VERKEERD OM?!
bobgiesberts 16:07d0e43c2d12 210
bobgiesberts 16:07d0e43c2d12 211 uint32_t readINTB(void); // EXTRA UNTB Read register
bobgiesberts 16:07d0e43c2d12 212 uint32_t INTB; // extra: read register INTB
bobgiesberts 16:07d0e43c2d12 213
bobgiesberts 19:e205ab9142d8 214 uint16_t _responsetime; // Response Time
bobgiesberts 19:e205ab9142d8 215 uint8_t _divider; // divider
bobgiesberts 19:e205ab9142d8 216 float _RPmin; // RP_MIN
bobgiesberts 19:e205ab9142d8 217 float _fsensor; // f_sensor: the calculated frequency of the sensor
bobgiesberts 19:e205ab9142d8 218 float _inductance; // the calculated inductance
bobgiesberts 19:e205ab9142d8 219 float _fCLKIN; // f_CLKIN: frequency of external clock: 16MHz
bobgiesberts 19:e205ab9142d8 220 float _cap; // capacitor: 120 pF
bobgiesberts 19:e205ab9142d8 221 uint32_t _L_data; // The raw measured data for inductance
bobgiesberts 19:e205ab9142d8 222 uint16_t _Rcount; // The reference count
bobgiesberts 19:e205ab9142d8 223
bobgiesberts 19:e205ab9142d8 224
bobgiesberts 16:07d0e43c2d12 225 SPI _spiport;
bobgiesberts 16:07d0e43c2d12 226 DigitalOut _cs_pin;
bobgiesberts 16:07d0e43c2d12 227
bobgiesberts 17:a5cf2b4bec13 228 //FastPWM _clock;
bobgiesberts 16:07d0e43c2d12 229 };
bobgiesberts 16:07d0e43c2d12 230
bobgiesberts 16:07d0e43c2d12 231 #endif