Nikollao Sulollari / Mbed 2 deprecated Fast_LIA_final

The project is a fast lock in amplifier (LIA) which can update its output at rate of 1000 measurements/s. It performs digital dual mixing and filtering to obtain a DC value proportional to the AC input signal.

Dependencies:   N5110 mbed

main.h@0:4e20939af8bb, 2017-08-21 (annotated)

Committer:
Nikollao
Date:
Mon Aug 21 11:22:14 2017 +0000
Revision:
0:4e20939af8bb
Child:
1:bf693859586c
LIA FAST DONE!

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Nikollao 0:4e20939af8bb 1 /**
Nikollao 0:4e20939af8bb 2 @file main.h
Nikollao 0:4e20939af8bb 3 @brief Header file contains functions and variables
Nikollao 0:4e20939af8bb 4 @brief Fast Lock-In Amplifier - AC to DC converter
Nikollao 0:4e20939af8bb 5 @brief Revision 1.0
Nikollao 0:4e20939af8bb 6 @author Nikollao Sulollari
Nikollao 0:4e20939af8bb 7 @Date 16/08/2017
Nikollao 0:4e20939af8bb 8 */
Nikollao 0:4e20939af8bb 9
Nikollao 0:4e20939af8bb 10 #ifndef MAIN_H
Nikollao 0:4e20939af8bb 11 #define MAIN_H
Nikollao 0:4e20939af8bb 12 #include "mbed.h"
Nikollao 0:4e20939af8bb 13
Nikollao 0:4e20939af8bb 14 #define DIRECTION_TOLERANCE 0.05
Nikollao 0:4e20939af8bb 15
Nikollao 0:4e20939af8bb 16 /**
Nikollao 0:4e20939af8bb 17 @namespace aout
Nikollao 0:4e20939af8bb 18 @brief Analog output DC filtered value
Nikollao 0:4e20939af8bb 19 */
Nikollao 0:4e20939af8bb 20 AnalogOut aout(DAC0_OUT);
Nikollao 0:4e20939af8bb 21
Nikollao 0:4e20939af8bb 22 /**
Nikollao 0:4e20939af8bb 23 @namespace gpo
Nikollao 0:4e20939af8bb 24 @brief Digital output set the D0 pin High/Low
Nikollao 0:4e20939af8bb 25 */
Nikollao 0:4e20939af8bb 26 DigitalOut gpo(D0);
Nikollao 0:4e20939af8bb 27
Nikollao 0:4e20939af8bb 28 /**
Nikollao 0:4e20939af8bb 29 @namespace ain
Nikollao 0:4e20939af8bb 30 @brief analog input which is the signal from the bolometer (THz detector)
Nikollao 0:4e20939af8bb 31 */
Nikollao 0:4e20939af8bb 32 AnalogIn ain(A0);
Nikollao 0:4e20939af8bb 33
Nikollao 0:4e20939af8bb 34 /**
Nikollao 0:4e20939af8bb 35 @namespace dref
Nikollao 0:4e20939af8bb 36 @brief event triggered interrupt used to calculate the reference frequency
Nikollao 0:4e20939af8bb 37 */
Nikollao 0:4e20939af8bb 38 InterruptIn dref(D6);
Nikollao 0:4e20939af8bb 39
Nikollao 0:4e20939af8bb 40 /**
Nikollao 0:4e20939af8bb 41 @namespace amp_ticker
Nikollao 0:4e20939af8bb 42 @brief time-triggered interrupt calculates the amplitude of the input signal
Nikollao 0:4e20939af8bb 43 */
Nikollao 0:4e20939af8bb 44 Ticker offset_ticker;
Nikollao 0:4e20939af8bb 45
Nikollao 0:4e20939af8bb 46 /**
Nikollao 0:4e20939af8bb 47 @namespace sample_ticker
Nikollao 0:4e20939af8bb 48 @brief time-triggered interrupt samples internal sine and cosine signals
Nikollao 0:4e20939af8bb 49 */
Nikollao 0:4e20939af8bb 50 Ticker sample_ticker;
Nikollao 0:4e20939af8bb 51
Nikollao 0:4e20939af8bb 52 /**
Nikollao 0:4e20939af8bb 53 @namespace output_ticker
Nikollao 0:4e20939af8bb 54 @brief time-triggered interrupt updates the output of Fast LIA
Nikollao 0:4e20939af8bb 55 */
Nikollao 0:4e20939af8bb 56 Ticker output_ticker;
Nikollao 0:4e20939af8bb 57
Nikollao 0:4e20939af8bb 58 /**
Nikollao 0:4e20939af8bb 59 @namespace period_timer
Nikollao 0:4e20939af8bb 60 @brief timer is used to calculate the frequency of the input square wave
Nikollao 0:4e20939af8bb 61 */
Nikollao 0:4e20939af8bb 62 Timer period_timer;
Nikollao 0:4e20939af8bb 63
Nikollao 0:4e20939af8bb 64
Nikollao 0:4e20939af8bb 65 /**
Nikollao 0:4e20939af8bb 66 @namespace period_timer
Nikollao 0:4e20939af8bb 67 @brief timer updates the output of the LIA depending on the time constant
Nikollao 0:4e20939af8bb 68 */
Nikollao 0:4e20939af8bb 69 Timer output_timer;
Nikollao 0:4e20939af8bb 70 /**
Nikollao 0:4e20939af8bb 71 @namespace lcd
Nikollao 0:4e20939af8bb 72 @brief object of the N5110 class
Nikollao 0:4e20939af8bb 73 */
Nikollao 0:4e20939af8bb 74 //N5110 lcd(PTE26 , PTA0 , PTC4 , PTD0 , PTD2 , PTD1 , PTC3);
Nikollao 0:4e20939af8bb 75
Nikollao 0:4e20939af8bb 76
Nikollao 0:4e20939af8bb 77 /**
Nikollao 0:4e20939af8bb 78 @namespace pc
Nikollao 0:4e20939af8bb 79 @brief serial connection between mbed and pc
Nikollao 0:4e20939af8bb 80 */
Nikollao 0:4e20939af8bb 81 Serial pc(USBTX,USBRX);
Nikollao 0:4e20939af8bb 82
Nikollao 0:4e20939af8bb 83 /**
Nikollao 0:4e20939af8bb 84 @namespace DirectionName
Nikollao 0:4e20939af8bb 85 @brief define joystick's direction based on its x,y values
Nikollao 0:4e20939af8bb 86 */
Nikollao 0:4e20939af8bb 87 enum DirectionName {
Nikollao 0:4e20939af8bb 88 UP,
Nikollao 0:4e20939af8bb 89 DOWN,
Nikollao 0:4e20939af8bb 90 LEFT,
Nikollao 0:4e20939af8bb 91 RIGHT,
Nikollao 0:4e20939af8bb 92 CENTRE,
Nikollao 0:4e20939af8bb 93 };
Nikollao 0:4e20939af8bb 94
Nikollao 0:4e20939af8bb 95 /**
Nikollao 0:4e20939af8bb 96 @namespace Joystick
Nikollao 0:4e20939af8bb 97 @brief create strcut Joystick
Nikollao 0:4e20939af8bb 98 */
Nikollao 0:4e20939af8bb 99 typedef struct JoyStick Joystick;
Nikollao 0:4e20939af8bb 100 struct JoyStick {
Nikollao 0:4e20939af8bb 101 double x; /// current x value
Nikollao 0:4e20939af8bb 102 double x0; /// 'centred' x value
Nikollao 0:4e20939af8bb 103 double y; /// current y value
Nikollao 0:4e20939af8bb 104 double y0; /// 'centred' y value
Nikollao 0:4e20939af8bb 105 int button; /// button state (assume pull-down used, so 1 = pressed, 0 = unpressed)
Nikollao 0:4e20939af8bb 106 DirectionName direction; // current direction
Nikollao 0:4e20939af8bb 107 };
Nikollao 0:4e20939af8bb 108 /// create struct variable
Nikollao 0:4e20939af8bb 109 Joystick joystick;
Nikollao 0:4e20939af8bb 110
Nikollao 0:4e20939af8bb 111 /**
Nikollao 0:4e20939af8bb 112 set-up serial port
Nikollao 0:4e20939af8bb 113 */
Nikollao 0:4e20939af8bb 114 void init_serial();
Nikollao 0:4e20939af8bb 115
Nikollao 0:4e20939af8bb 116 /**
Nikollao 0:4e20939af8bb 117 initialise lcd and serial
Nikollao 0:4e20939af8bb 118 */
Nikollao 0:4e20939af8bb 119 void program_init();
Nikollao 0:4e20939af8bb 120
Nikollao 0:4e20939af8bb 121 /**
Nikollao 0:4e20939af8bb 122 use MCU in High Power Mode and set Core, ADC, and BUS clocks at max
Nikollao 0:4e20939af8bb 123 */
Nikollao 0:4e20939af8bb 124 void setupK64Fclocks();
Nikollao 0:4e20939af8bb 125
Nikollao 0:4e20939af8bb 126 /**
Nikollao 0:4e20939af8bb 127 initialise DAC pin, otherwise AnalogOut (dac0_out) does not work
Nikollao 0:4e20939af8bb 128 */
Nikollao 0:4e20939af8bb 129 void initDAC();
Nikollao 0:4e20939af8bb 130
Nikollao 0:4e20939af8bb 131 /**
Nikollao 0:4e20939af8bb 132 ISR sets flag to find Amplitude of bolometer signal
Nikollao 0:4e20939af8bb 133 */
Nikollao 0:4e20939af8bb 134 void findAmplitude();
Nikollao 0:4e20939af8bb 135
Nikollao 0:4e20939af8bb 136 /**
Nikollao 0:4e20939af8bb 137 find the amplitude of the analog bolometer signal
Nikollao 0:4e20939af8bb 138 */
Nikollao 0:4e20939af8bb 139 double max(int points);
Nikollao 0:4e20939af8bb 140
Nikollao 0:4e20939af8bb 141 double mavg_filter(int filt_points);
Nikollao 0:4e20939af8bb 142
Nikollao 0:4e20939af8bb 143 /**
Nikollao 0:4e20939af8bb 144 ISR sets flag to update LIA output
Nikollao 0:4e20939af8bb 145 */
Nikollao 0:4e20939af8bb 146 void updateOutput();
Nikollao 0:4e20939af8bb 147
Nikollao 0:4e20939af8bb 148 /**
Nikollao 0:4e20939af8bb 149 ISR sets flag to mix signals
Nikollao 0:4e20939af8bb 150 */
Nikollao 0:4e20939af8bb 151 void mixSignals();
Nikollao 0:4e20939af8bb 152
Nikollao 0:4e20939af8bb 153 /**
Nikollao 0:4e20939af8bb 154 performs digital mixing with refX and refY components
Nikollao 0:4e20939af8bb 155 */
Nikollao 0:4e20939af8bb 156 void digitalMix(double remove_offset);
Nikollao 0:4e20939af8bb 157
Nikollao 0:4e20939af8bb 158 /**
Nikollao 0:4e20939af8bb 159 moving average filter with n points (n = 17)
Nikollao 0:4e20939af8bb 160 */
Nikollao 0:4e20939af8bb 161 void filterSignal(int averages);
Nikollao 0:4e20939af8bb 162
Nikollao 0:4e20939af8bb 163 /**
Nikollao 0:4e20939af8bb 164 ISR calculates the DigitalIn signal frequency
Nikollao 0:4e20939af8bb 165 */
Nikollao 0:4e20939af8bb 166 void voltageRise();
Nikollao 0:4e20939af8bb 167
Nikollao 0:4e20939af8bb 168 /**
Nikollao 0:4e20939af8bb 169 ISR calculates the offset of the bolometer signal
Nikollao 0:4e20939af8bb 170 */
Nikollao 0:4e20939af8bb 171 void offset_isr();
Nikollao 0:4e20939af8bb 172
Nikollao 0:4e20939af8bb 173 void output_isr();
Nikollao 0:4e20939af8bb 174
Nikollao 0:4e20939af8bb 175 double calculate_constant(double freq_ref);
Nikollao 0:4e20939af8bb 176
Nikollao 0:4e20939af8bb 177 /*!< used to assign the amplitude of the bolometer signal */
Nikollao 0:4e20939af8bb 178 volatile double amplitude = 0;
Nikollao 0:4e20939af8bb 179
Nikollao 0:4e20939af8bb 180 /*!< used to find the offset of the input signal */
Nikollao 0:4e20939af8bb 181 volatile double outDC = 0;
Nikollao 0:4e20939af8bb 182
Nikollao 0:4e20939af8bb 183 /*!< stores the period of the input digital signal */
Nikollao 0:4e20939af8bb 184 volatile double ref_period = 0;
Nikollao 0:4e20939af8bb 185
Nikollao 0:4e20939af8bb 186 /*!< stores the frequency of the input digital signal */
Nikollao 0:4e20939af8bb 187 volatile double ref_freq = 0;
Nikollao 0:4e20939af8bb 188
Nikollao 0:4e20939af8bb 189 /*!< counter is used to find take between two rises of digital signal*/
Nikollao 0:4e20939af8bb 190 volatile int g_counter = 1;
Nikollao 0:4e20939af8bb 191
Nikollao 0:4e20939af8bb 192 /*!< flag is set from ISR to find offset of the bolometer signal */
Nikollao 0:4e20939af8bb 193 volatile int g_offset_flag = 0;
Nikollao 0:4e20939af8bb 194
Nikollao 0:4e20939af8bb 195 /*!< sampling period to take n samples and find bolometer signal amplitude */
Nikollao 0:4e20939af8bb 196 volatile double amplitude_delay = 0;
Nikollao 0:4e20939af8bb 197
Nikollao 0:4e20939af8bb 198 /*!< flag used to update output */
Nikollao 0:4e20939af8bb 199 volatile int g_output_flag = 0;
Nikollao 0:4e20939af8bb 200
Nikollao 0:4e20939af8bb 201 /*!< flag used to sample internal sine/cosine signals */
Nikollao 0:4e20939af8bb 202 volatile int g_sample_flag = 0;
Nikollao 0:4e20939af8bb 203
Nikollao 0:4e20939af8bb 204 /*!< array stores the square root of X^2 and Y^2 */
Nikollao 0:4e20939af8bb 205 volatile double R[16];
Nikollao 0:4e20939af8bb 206
Nikollao 0:4e20939af8bb 207 /*!< store the bolometer signal and find max value */
Nikollao 0:4e20939af8bb 208 double bolometer_signal[8];
Nikollao 0:4e20939af8bb 209
Nikollao 0:4e20939af8bb 210 /*!< store the bolometer signal and find max value */
Nikollao 0:4e20939af8bb 211 double bol_signal;
Nikollao 0:4e20939af8bb 212 //int size = 16;
Nikollao 0:4e20939af8bb 213
Nikollao 0:4e20939af8bb 214 /*!< variable used if a sine/cosine of 8 discrete values is used */
Nikollao 0:4e20939af8bb 215 int samples8 = 8;
Nikollao 0:4e20939af8bb 216
Nikollao 0:4e20939af8bb 217 /*!< variable used if a sine/cosine of 17 discrete values is used */
Nikollao 0:4e20939af8bb 218 int samples16 = 16;
Nikollao 0:4e20939af8bb 219
Nikollao 0:4e20939af8bb 220 /*!< variable used if a sine/cosine of 32 discrete values is used */
Nikollao 0:4e20939af8bb 221 int samples32 = 32;
Nikollao 0:4e20939af8bb 222
Nikollao 0:4e20939af8bb 223 /*!< sampling frequency of the internal sine/cosine waves */
Nikollao 0:4e20939af8bb 224 double sample_freq = 0;
Nikollao 0:4e20939af8bb 225
Nikollao 0:4e20939af8bb 226 /*!< variable used to sample the internal sine/cosine waves */
Nikollao 0:4e20939af8bb 227 double sample_time = 0;
Nikollao 0:4e20939af8bb 228
Nikollao 0:4e20939af8bb 229 /*!< number of samples for the amplitude of the bolometer signal */
Nikollao 0:4e20939af8bb 230 int amp_points = 32;
Nikollao 0:4e20939af8bb 231
Nikollao 0:4e20939af8bb 232 /*!< sampling freq to find the amplitude of the bolomter signal */
Nikollao 0:4e20939af8bb 233 double delay_freq = 0;
Nikollao 0:4e20939af8bb 234
Nikollao 0:4e20939af8bb 235 /*!< read the timer and if it is equal to the time constant update output */
Nikollao 0:4e20939af8bb 236 double time_out = 0;
Nikollao 0:4e20939af8bb 237
Nikollao 0:4e20939af8bb 238 int filter_points = 500;
Nikollao 0:4e20939af8bb 239
Nikollao 0:4e20939af8bb 240 double offset = 0;
Nikollao 0:4e20939af8bb 241
Nikollao 0:4e20939af8bb 242 /*!< sine wave array with 32 values */
Nikollao 0:4e20939af8bb 243 static double sin_array32[32] = {0, 0.1951, 0.3827, 0.5556, 0.7071, 0.8315, 0.9239,
Nikollao 0:4e20939af8bb 244 0.9808, 1, 0.9808, 0.9239, 0.8315, 0.7071, 0.5556,
Nikollao 0:4e20939af8bb 245 0.3827, 0.1951, 0, -0.1951, -0.3827, -0.5556, -0.7071,
Nikollao 0:4e20939af8bb 246 -0.8315, -0.9239, -0.9808, -1, -0.9808, -0.9239, -0.8315,
Nikollao 0:4e20939af8bb 247 -0.7071, -0.5556, -0.3827, -0.1951
Nikollao 0:4e20939af8bb 248 };
Nikollao 0:4e20939af8bb 249
Nikollao 0:4e20939af8bb 250 /*!< cosine wave array with 32 values */
Nikollao 0:4e20939af8bb 251 static double cos_array32[32] = {1, 0.9808, 0.9239, 0.8315, 0.7071, 0.5556,
Nikollao 0:4e20939af8bb 252 0.3827, 0.1951, 0, -0.1951, -0.3827, -0.5556, -0.7071,
Nikollao 0:4e20939af8bb 253 -0.8315, -0.9239, -0.9808, -1, -0.9808, -0.9239, -0.8315,
Nikollao 0:4e20939af8bb 254 -0.7071, -0.5556, -0.3827, -0.1951, 0, 0.1951, 0.3827,
Nikollao 0:4e20939af8bb 255 0.5556, 0.7071, 0.8315, 0.9239, 0.9808
Nikollao 0:4e20939af8bb 256 };
Nikollao 0:4e20939af8bb 257
Nikollao 0:4e20939af8bb 258 /*!< sine wave array with 17 values */
Nikollao 0:4e20939af8bb 259 static double sin_array16[16] = {0, 0.3827, 0.7071, 0.9239, 1, 0.9239, 0.7071,
Nikollao 0:4e20939af8bb 260 0.3827, 0, -0.3827, -0.7071, -0.9239, -1, -0.9239
Nikollao 0:4e20939af8bb 261 ,-0.7071, -0.3827,
Nikollao 0:4e20939af8bb 262 };
Nikollao 0:4e20939af8bb 263
Nikollao 0:4e20939af8bb 264 /*!< sine wave array with delay and 16 values, used for testing output */
Nikollao 0:4e20939af8bb 265 static double sin_array16delay[16] = {0.7071, 0.9239, 1, 0.9239, 0.7071,
Nikollao 0:4e20939af8bb 266 0.3827, 0, -0.3827, -0.7071, -0.9239, -1, -0.9239
Nikollao 0:4e20939af8bb 267 ,-0.7071, -0.3827, 0, 0.3827
Nikollao 0:4e20939af8bb 268 };
Nikollao 0:4e20939af8bb 269
Nikollao 0:4e20939af8bb 270 /*!< cosine wave array with 17 values */
Nikollao 0:4e20939af8bb 271 static double cos_array16[16] = {1, 0.9239, 0.7071,
Nikollao 0:4e20939af8bb 272 0.3827, 0, -0.3827, -0.7071, -0.9239, -1, -0.9239
Nikollao 0:4e20939af8bb 273 ,-0.7071, -0.3827, 0, 0.3827, 0.7071, 0.9239,
Nikollao 0:4e20939af8bb 274 };
Nikollao 0:4e20939af8bb 275
Nikollao 0:4e20939af8bb 276 /*!< sine wave array with 8 values */
Nikollao 0:4e20939af8bb 277 static double sin_array8[8] = {0, 0.7071, 1, 0.7071, 0, -0.7071, -1, -0.7071};
Nikollao 0:4e20939af8bb 278
Nikollao 0:4e20939af8bb 279 /*!< cosine wave array with 8 values */
Nikollao 0:4e20939af8bb 280 static double cos_array8[8] = {1, 0.7071, 0, -0.7071, -1, -0.7071, 0, 0.7071};
Nikollao 0:4e20939af8bb 281
Nikollao 0:4e20939af8bb 282 #endif