Alvaro Cassinelli / laserProjectorHardware

Hardware control: mirrors

hardwareIO.cpp@0:3fe2fe307968, 2012-08-01 (annotated)

Committer:
mbedalvaro
Date:
Wed Aug 01 03:01:45 2012 +0000
Revision:
0:3fe2fe307968
Child:
1:b1f5ed22087a
[mbed] converted /scoreLight_Advanced/hardwareIO

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbedalvaro 0:3fe2fe307968 1 #include "hardwareIO.h"
mbedalvaro 0:3fe2fe307968 2
mbedalvaro 0:3fe2fe307968 3 HardwareIO IO; // preintantiation of cross-file global object IO
mbedalvaro 0:3fe2fe307968 4
mbedalvaro 0:3fe2fe307968 5 // -------------------------------------- (0) SETUP ALL IO (call this in the setup() function in main program)
mbedalvaro 0:3fe2fe307968 6
mbedalvaro 0:3fe2fe307968 7 Serial pc(USBTX, USBRX); // tx, rx
mbedalvaro 0:3fe2fe307968 8 LocalFileSystem local("local"); // Create the local filesystem under the name "local"
mbedalvaro 0:3fe2fe307968 9
mbedalvaro 0:3fe2fe307968 10 SPI spiDAC(MOSI_PIN, MISO_PIN, SCK_PIN); // mosi, miso, sclk
mbedalvaro 0:3fe2fe307968 11 DigitalOut csDAC(CS_DAC_MIRRORS);
mbedalvaro 0:3fe2fe307968 12
mbedalvaro 0:3fe2fe307968 13 AnalogIn ain(POT_ANALOG_INPUT);
mbedalvaro 0:3fe2fe307968 14
mbedalvaro 0:3fe2fe307968 15 DigitalOut Laser_Red(LASER_RED_PIN); // NOTE: this is NOT the lock in sensing laser (actually, not used yet)
mbedalvaro 0:3fe2fe307968 16 DigitalOut Laser_Green(LASER_GREEN_PIN);
mbedalvaro 0:3fe2fe307968 17 DigitalOut Laser_Blue(LASER_BLUE_PIN);
mbedalvaro 0:3fe2fe307968 18
mbedalvaro 0:3fe2fe307968 19 void HardwareIO::init(void) {
mbedalvaro 0:3fe2fe307968 20 Laser_Red = 0; // note: this is not the lockin-laser!
mbedalvaro 0:3fe2fe307968 21 Laser_Green = 0;
mbedalvaro 0:3fe2fe307968 22 Laser_Blue = 0;
mbedalvaro 0:3fe2fe307968 23
mbedalvaro 0:3fe2fe307968 24 //Serial Communication setup:
mbedalvaro 0:3fe2fe307968 25 pc.baud(115200);//
mbedalvaro 0:3fe2fe307968 26 // pc.baud(921600);//115200);//
mbedalvaro 0:3fe2fe307968 27
mbedalvaro 0:3fe2fe307968 28 // Setup for lock-in amplifier and pwm references:
mbedalvaro 0:3fe2fe307968 29 lockin.init();
mbedalvaro 0:3fe2fe307968 30
mbedalvaro 0:3fe2fe307968 31 // Setup the spi for 8 bit data, high steady state clock,
mbedalvaro 0:3fe2fe307968 32 // second edge capture, with a 10MHz clock rate
mbedalvaro 0:3fe2fe307968 33 csDAC = 1;
mbedalvaro 0:3fe2fe307968 34 spiDAC.format(16,0);
mbedalvaro 0:3fe2fe307968 35 spiDAC.frequency(16000000);
mbedalvaro 0:3fe2fe307968 36
mbedalvaro 0:3fe2fe307968 37 // default initial mirror position:
mbedalvaro 0:3fe2fe307968 38 writeOutX(CENTER_AD_MIRROR_X);
mbedalvaro 0:3fe2fe307968 39 writeOutY(CENTER_AD_MIRROR_Y);
mbedalvaro 0:3fe2fe307968 40
mbedalvaro 0:3fe2fe307968 41 // Load LUT table:
mbedalvaro 0:3fe2fe307968 42 setLUT();
mbedalvaro 0:3fe2fe307968 43 }
mbedalvaro 0:3fe2fe307968 44
mbedalvaro 0:3fe2fe307968 45 //write on the first DAC, output A (mirror X)
mbedalvaro 0:3fe2fe307968 46 void HardwareIO::writeOutX(unsigned short value){
mbedalvaro 0:3fe2fe307968 47 if(value > MAX_AD_MIRRORS) value = MAX_AD_MIRRORS;
mbedalvaro 0:3fe2fe307968 48 if(value < MIN_AD_MIRRORS) value = MIN_AD_MIRRORS;
mbedalvaro 0:3fe2fe307968 49
mbedalvaro 0:3fe2fe307968 50 value |= 0x7000;
mbedalvaro 0:3fe2fe307968 51 value &= 0x7FFF;
mbedalvaro 0:3fe2fe307968 52
mbedalvaro 0:3fe2fe307968 53 csDAC = 0;
mbedalvaro 0:3fe2fe307968 54 spiDAC.write(value);
mbedalvaro 0:3fe2fe307968 55 csDAC = 1;
mbedalvaro 0:3fe2fe307968 56 }
mbedalvaro 0:3fe2fe307968 57
mbedalvaro 0:3fe2fe307968 58 //write on the first DAC, output B (mirror Y)
mbedalvaro 0:3fe2fe307968 59 void HardwareIO::writeOutY(unsigned short value){
mbedalvaro 0:3fe2fe307968 60 if(value > MAX_AD_MIRRORS) value = MAX_AD_MIRRORS;
mbedalvaro 0:3fe2fe307968 61 if(value < MIN_AD_MIRRORS) value = MIN_AD_MIRRORS;
mbedalvaro 0:3fe2fe307968 62
mbedalvaro 0:3fe2fe307968 63 value |= 0xF000;
mbedalvaro 0:3fe2fe307968 64 value &= 0xFFFF;
mbedalvaro 0:3fe2fe307968 65
mbedalvaro 0:3fe2fe307968 66 csDAC = 0;
mbedalvaro 0:3fe2fe307968 67 spiDAC.write(value);
mbedalvaro 0:3fe2fe307968 68 csDAC = 1;
mbedalvaro 0:3fe2fe307968 69 }
mbedalvaro 0:3fe2fe307968 70
mbedalvaro 0:3fe2fe307968 71 void HardwareIO::setRedPower(int powerValue){
mbedalvaro 0:3fe2fe307968 72 if(powerValue > 0){
mbedalvaro 0:3fe2fe307968 73 lockin.setLaserPower(true);
mbedalvaro 0:3fe2fe307968 74 }
mbedalvaro 0:3fe2fe307968 75 else{
mbedalvaro 0:3fe2fe307968 76 lockin.setLaserPower(false);
mbedalvaro 0:3fe2fe307968 77 }
mbedalvaro 0:3fe2fe307968 78 }
mbedalvaro 0:3fe2fe307968 79 void HardwareIO::setGreenPower(int powerValue){
mbedalvaro 0:3fe2fe307968 80 if(powerValue > 0){
mbedalvaro 0:3fe2fe307968 81 Laser_Green = 1;
mbedalvaro 0:3fe2fe307968 82 }
mbedalvaro 0:3fe2fe307968 83 else{
mbedalvaro 0:3fe2fe307968 84 Laser_Green = 0;
mbedalvaro 0:3fe2fe307968 85 }
mbedalvaro 0:3fe2fe307968 86 }
mbedalvaro 0:3fe2fe307968 87 void HardwareIO::setBluePower(int powerValue){
mbedalvaro 0:3fe2fe307968 88 if(powerValue > 0){
mbedalvaro 0:3fe2fe307968 89 Laser_Blue = 1;
mbedalvaro 0:3fe2fe307968 90 }
mbedalvaro 0:3fe2fe307968 91 else{
mbedalvaro 0:3fe2fe307968 92 Laser_Blue = 0;
mbedalvaro 0:3fe2fe307968 93 }
mbedalvaro 0:3fe2fe307968 94 }
mbedalvaro 0:3fe2fe307968 95
mbedalvaro 0:3fe2fe307968 96 void HardwareIO::setRGBPower(unsigned char color) {
mbedalvaro 0:3fe2fe307968 97 lockin.setLaserPower(color&0x04>0? false : true);
mbedalvaro 0:3fe2fe307968 98 Laser_Green=(color&0x02)>>1;
mbedalvaro 0:3fe2fe307968 99 Laser_Blue =color&0x01;
mbedalvaro 0:3fe2fe307968 100 }
mbedalvaro 0:3fe2fe307968 101
mbedalvaro 0:3fe2fe307968 102 void HardwareIO::showLimitsMirrors(int times) {
mbedalvaro 0:3fe2fe307968 103 unsigned short pointsPerLine=150;
mbedalvaro 0:3fe2fe307968 104 int shiftX = (MAX_AD_MIRRORS - MIN_AD_MIRRORS) / pointsPerLine;
mbedalvaro 0:3fe2fe307968 105 int shiftY = (MAX_AD_MIRRORS - MIN_AD_MIRRORS) / pointsPerLine;
mbedalvaro 0:3fe2fe307968 106
mbedalvaro 0:3fe2fe307968 107 Laser_Green=1;
mbedalvaro 0:3fe2fe307968 108
mbedalvaro 0:3fe2fe307968 109 //for (int repeat=0; repeat<times; repeat++) {
mbedalvaro 0:3fe2fe307968 110
mbedalvaro 0:3fe2fe307968 111 Timer t;
mbedalvaro 0:3fe2fe307968 112 t.start();
mbedalvaro 0:3fe2fe307968 113 while(t.read_ms()<times*1000) {
mbedalvaro 0:3fe2fe307968 114
mbedalvaro 0:3fe2fe307968 115 writeOutX(MIN_AD_MIRRORS);writeOutY(MIN_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 116
mbedalvaro 0:3fe2fe307968 117 for(int j=0; j<pointsPerLine; j++){
mbedalvaro 0:3fe2fe307968 118 wait_us(200);//delay between each points
mbedalvaro 0:3fe2fe307968 119 writeOutY(j*shiftY + MIN_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 120 }
mbedalvaro 0:3fe2fe307968 121
mbedalvaro 0:3fe2fe307968 122 writeOutX(MIN_AD_MIRRORS);writeOutY(MAX_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 123 for(int j=0; j<pointsPerLine; j++) {
mbedalvaro 0:3fe2fe307968 124 wait_us(200);//delay between each points
mbedalvaro 0:3fe2fe307968 125 writeOutX(j*shiftX + MIN_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 126 }
mbedalvaro 0:3fe2fe307968 127
mbedalvaro 0:3fe2fe307968 128 writeOutX(MAX_AD_MIRRORS);writeOutY(MAX_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 129 for(int j=0; j<pointsPerLine; j++) {
mbedalvaro 0:3fe2fe307968 130 wait_us(200);//delay between each points
mbedalvaro 0:3fe2fe307968 131 writeOutY(-j*shiftX + MAX_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 132 }
mbedalvaro 0:3fe2fe307968 133
mbedalvaro 0:3fe2fe307968 134 writeOutX(MAX_AD_MIRRORS);writeOutY(MIN_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 135 for(int j=0; j<pointsPerLine; j++) {
mbedalvaro 0:3fe2fe307968 136 wait_us(200);//delay between each points
mbedalvaro 0:3fe2fe307968 137 writeOutX(-j*shiftX + MAX_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 138 }
mbedalvaro 0:3fe2fe307968 139
mbedalvaro 0:3fe2fe307968 140 }
mbedalvaro 0:3fe2fe307968 141 t.stop();
mbedalvaro 0:3fe2fe307968 142 Laser_Green=0;
mbedalvaro 0:3fe2fe307968 143 }
mbedalvaro 0:3fe2fe307968 144
mbedalvaro 0:3fe2fe307968 145 void HardwareIO::scan_serial(unsigned short pointsPerLine){
mbedalvaro 0:3fe2fe307968 146 //scan the total surface with a custom resolution
mbedalvaro 0:3fe2fe307968 147 //send the lockin value for each point as a byte on the serial port to the PC
mbedalvaro 0:3fe2fe307968 148 //use "scanSLP_save" to see the data on processing
mbedalvaro 0:3fe2fe307968 149
mbedalvaro 0:3fe2fe307968 150
mbedalvaro 0:3fe2fe307968 151 int shiftX = (MAX_AD_MIRRORS - MIN_AD_MIRRORS) / pointsPerLine;
mbedalvaro 0:3fe2fe307968 152 int shiftY = (MAX_AD_MIRRORS - MIN_AD_MIRRORS) / pointsPerLine;
mbedalvaro 0:3fe2fe307968 153
mbedalvaro 0:3fe2fe307968 154 for(int j=0; j<pointsPerLine; j++){
mbedalvaro 0:3fe2fe307968 155 writeOutX(MIN_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 156 writeOutY(j*shiftY + MIN_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 157
mbedalvaro 0:3fe2fe307968 158 wait_us(300);//begining of line delay
mbedalvaro 0:3fe2fe307968 159 for(int i=0; i<pointsPerLine; i++){
mbedalvaro 0:3fe2fe307968 160 writeOutX(i*shiftX + MIN_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 161
mbedalvaro 0:3fe2fe307968 162 wait_us(200);//delay between each points
mbedalvaro 0:3fe2fe307968 163
mbedalvaro 0:3fe2fe307968 164 // SEND A VALUE BETWEEN 0 and 255:
mbedalvaro 0:3fe2fe307968 165 pc.putc(int(255.0*lockin.getMedianValue()/4095));//printf("%dL",int(valueLockin*255));//pc.putc(int(lockin*255));//
mbedalvaro 0:3fe2fe307968 166 }
mbedalvaro 0:3fe2fe307968 167 }
mbedalvaro 0:3fe2fe307968 168 }
mbedalvaro 0:3fe2fe307968 169
mbedalvaro 0:3fe2fe307968 170 //load Look-up Table from LUT.TXT file
mbedalvaro 0:3fe2fe307968 171 //or create the file with scanLUT() if not existing.
mbedalvaro 0:3fe2fe307968 172 void HardwareIO::setLUT(){
mbedalvaro 0:3fe2fe307968 173
mbedalvaro 0:3fe2fe307968 174 FILE *fp = fopen(LUT_FILENAME, "r"); // Open file on the local file system for writing
mbedalvaro 0:3fe2fe307968 175 if(fp){
mbedalvaro 0:3fe2fe307968 176 //load the file into the lut table; keep the SAME resolution!
mbedalvaro 0:3fe2fe307968 177 fread(lut,sizeof(uint16),LUT_RESOLUTION*LUT_RESOLUTION,fp);
mbedalvaro 0:3fe2fe307968 178 fclose(fp);
mbedalvaro 0:3fe2fe307968 179 }
mbedalvaro 0:3fe2fe307968 180 else{
mbedalvaro 0:3fe2fe307968 181 //fclose(fp);
mbedalvaro 0:3fe2fe307968 182 //if the file "LUT.TXT" doesn't exist, create one with scanLUT()
mbedalvaro 0:3fe2fe307968 183 lockin.setLaserPower(true);
mbedalvaro 0:3fe2fe307968 184 scanLUT();
mbedalvaro 0:3fe2fe307968 185 }
mbedalvaro 0:3fe2fe307968 186
mbedalvaro 0:3fe2fe307968 187 }
mbedalvaro 0:3fe2fe307968 188
mbedalvaro 0:3fe2fe307968 189 //scan the total surface with a fixed 2^x resolution
mbedalvaro 0:3fe2fe307968 190 //create the Look-Up Table used to "flatten" the scan according to the position
mbedalvaro 0:3fe2fe307968 191 //
mbedalvaro 0:3fe2fe307968 192 //To Do: maybe detect high frequency to be sure the area is clean and empty?
mbedalvaro 0:3fe2fe307968 193 void HardwareIO::scanLUT(){
mbedalvaro 0:3fe2fe307968 194
mbedalvaro 0:3fe2fe307968 195 //reset lut table
mbedalvaro 0:3fe2fe307968 196 for(int j=0; j<LUT_RESOLUTION; j++){
mbedalvaro 0:3fe2fe307968 197 for(int i=0; i<LUT_RESOLUTION; i++){
mbedalvaro 0:3fe2fe307968 198 lut[i][j] =0;
mbedalvaro 0:3fe2fe307968 199 }
mbedalvaro 0:3fe2fe307968 200 }
mbedalvaro 0:3fe2fe307968 201
mbedalvaro 0:3fe2fe307968 202 int delayScanning = 300; //in us
mbedalvaro 0:3fe2fe307968 203
mbedalvaro 0:3fe2fe307968 204 //define the distance between each points (from 0 to 4096) and the offset (here 0)
mbedalvaro 0:3fe2fe307968 205 float shiftX = 1.0*(MAX_AD_MIRRORS - MIN_AD_MIRRORS) / (LUT_RESOLUTION-1);
mbedalvaro 0:3fe2fe307968 206 float shiftY = 1.0*(MAX_AD_MIRRORS - MIN_AD_MIRRORS) / (LUT_RESOLUTION-1);
mbedalvaro 0:3fe2fe307968 207 float offsetX = MIN_AD_MIRRORS;
mbedalvaro 0:3fe2fe307968 208 float offsetY = MIN_AD_MIRRORS;
mbedalvaro 0:3fe2fe307968 209
mbedalvaro 0:3fe2fe307968 210 //move the mirrors to the first position
mbedalvaro 0:3fe2fe307968 211 writeOutX(MAX_AD_MIRRORS);writeOutY(MIN_AD_MIRRORS);
mbedalvaro 0:3fe2fe307968 212 wait_us(500);
mbedalvaro 0:3fe2fe307968 213
mbedalvaro 0:3fe2fe307968 214 float x, y;
mbedalvaro 0:3fe2fe307968 215
mbedalvaro 0:3fe2fe307968 216 //scan the surface NB_SCANS times
mbedalvaro 0:3fe2fe307968 217 //the total value in lut[i][j] shouldn't exceed uint16 !!!
mbedalvaro 0:3fe2fe307968 218 for(int loop=0; loop<NB_SCANS; loop++){
mbedalvaro 0:3fe2fe307968 219 for(int j=0; j<LUT_RESOLUTION; j++){
mbedalvaro 0:3fe2fe307968 220 y = shiftY*j + offsetY ;
mbedalvaro 0:3fe2fe307968 221 writeOutY(int(y));
mbedalvaro 0:3fe2fe307968 222 //scan from right to left
mbedalvaro 0:3fe2fe307968 223 for(int i=LUT_RESOLUTION-1; i>=0; i--){
mbedalvaro 0:3fe2fe307968 224 x = shiftX*i + offsetX;
mbedalvaro 0:3fe2fe307968 225 writeOutX(int(x));
mbedalvaro 0:3fe2fe307968 226 wait_us(delayScanning);
mbedalvaro 0:3fe2fe307968 227 lut[i][j] += lockin_read();
mbedalvaro 0:3fe2fe307968 228 }
mbedalvaro 0:3fe2fe307968 229 //re-scan from left to right
mbedalvaro 0:3fe2fe307968 230 for(int i=0; i<LUT_RESOLUTION; i++){
mbedalvaro 0:3fe2fe307968 231 x = shiftX*i + offsetX;
mbedalvaro 0:3fe2fe307968 232 writeOutX(int(x));
mbedalvaro 0:3fe2fe307968 233 wait_us(delayScanning);
mbedalvaro 0:3fe2fe307968 234 lut[i][j] += lockin_read();
mbedalvaro 0:3fe2fe307968 235 }
mbedalvaro 0:3fe2fe307968 236 }
mbedalvaro 0:3fe2fe307968 237 }
mbedalvaro 0:3fe2fe307968 238
mbedalvaro 0:3fe2fe307968 239
mbedalvaro 0:3fe2fe307968 240 //save tab in file
mbedalvaro 0:3fe2fe307968 241 FILE *fp;
mbedalvaro 0:3fe2fe307968 242 #ifdef LUT_FILENAME
mbedalvaro 0:3fe2fe307968 243 fp = fopen(LUT_FILENAME, "w"); // Open file on the local file system for writing
mbedalvaro 0:3fe2fe307968 244 fwrite(lut,sizeof(uint16),LUT_RESOLUTION*LUT_RESOLUTION,fp);
mbedalvaro 0:3fe2fe307968 245 fclose(fp); //close the file (the mBed will appear connected again)
mbedalvaro 0:3fe2fe307968 246 #endif
mbedalvaro 0:3fe2fe307968 247
mbedalvaro 0:3fe2fe307968 248 #ifdef LUT_H_FILENAME
mbedalvaro 0:3fe2fe307968 249 //save tab in Human readable file (not used by the program, this is just for checking)
mbedalvaro 0:3fe2fe307968 250 // NOTE: we divide the content of the lut table by NB_SCANS, for easy reading (values should be between 0-4095)
mbedalvaro 0:3fe2fe307968 251 fp = fopen(LUT_H_FILENAME, "w"); // Open file on the local file system for writing
mbedalvaro 0:3fe2fe307968 252 fprintf(fp, "scan resolution: %d x %d\r\n",LUT_RESOLUTION, LUT_RESOLUTION);
mbedalvaro 0:3fe2fe307968 253 for(int j=0; j<LUT_RESOLUTION; j++){
mbedalvaro 0:3fe2fe307968 254 for(int i=0; i<LUT_RESOLUTION; i++){
mbedalvaro 0:3fe2fe307968 255 fprintf(fp, "X=%d,\tY=%d,\tI=%d\t \r\n", int(shiftX*i + offsetX), int(shiftY*j + offsetY), int(1.0*lut[i][j]/NB_SCANS) );
mbedalvaro 0:3fe2fe307968 256 }
mbedalvaro 0:3fe2fe307968 257 }
mbedalvaro 0:3fe2fe307968 258 fclose(fp); //close the file (the mBed will appear connected again)
mbedalvaro 0:3fe2fe307968 259 #endif
mbedalvaro 0:3fe2fe307968 260
mbedalvaro 0:3fe2fe307968 261 }
mbedalvaro 0:3fe2fe307968 262
mbedalvaro 0:3fe2fe307968 263
mbedalvaro 0:3fe2fe307968 264 //Return the lockin value "corrected with the Look-UpTable" - this means a RATIO between two reflectivities (and normally, this is <1).
mbedalvaro 0:3fe2fe307968 265 float HardwareIO::lockInCorrectedValue(unsigned short x, unsigned short y){
mbedalvaro 0:3fe2fe307968 266 //*******Correction using DIRECT approximation
mbedalvaro 0:3fe2fe307968 267 #ifdef LUT_DIRECT
mbedalvaro 0:3fe2fe307968 268 return 2.0* NB_SCANS * lockin_read() / (lut[x >> LUT_BITS_SHIFT][y >> LUT_BITS_SHIFT]); // 2 * NB_SCANS is the number of recorded sample added to one position of the LUT (scan is performed twice: left-right and right-left)
mbedalvaro 0:3fe2fe307968 269 #endif
mbedalvaro 0:3fe2fe307968 270
mbedalvaro 0:3fe2fe307968 271 //*******Correction using BILINEAR approximation
mbedalvaro 0:3fe2fe307968 272 #ifdef LUT_BILINEAR
mbedalvaro 0:3fe2fe307968 273 unsigned short X = x >> LUT_BITS_SHIFT; //mirror "x" is 12bits, LUT "X" needs 4bits when lut is 17x17
mbedalvaro 0:3fe2fe307968 274 unsigned short Y = y >> LUT_BITS_SHIFT; //mirror "y" is 12bits, LUT "Y" needs 4bits when lut is 17x17
mbedalvaro 0:3fe2fe307968 275 float dx = 1.0*(x & LUT_BITS_MASK)/(LUT_BITS_MASK+1); //weight to apply on X (mask with 255 and norm)
mbedalvaro 0:3fe2fe307968 276 float dy = 1.0*(y & LUT_BITS_MASK)/(LUT_BITS_MASK+1); //weight to apply on Y (mask with 255 and norm)
mbedalvaro 0:3fe2fe307968 277
mbedalvaro 0:3fe2fe307968 278 //Wheighted mean approximation of the Look-Up Table at the position (x,y):
mbedalvaro 0:3fe2fe307968 279 float wmLUT = (1-dy)*( (1-dx)*lut[X][Y] + dx*lut[X+1][Y] ) + dy*( (1-dx)*lut[X][Y+1] + dx*lut[X+1][Y+1] );
mbedalvaro 0:3fe2fe307968 280
mbedalvaro 0:3fe2fe307968 281 return 2.0* NB_SCANS * lockin_read() / wmLUT;// 2 * NB_SCANS is the number of recorded sample added to one position of the LUT (scan is performed twice: left-right and right-left)
mbedalvaro 0:3fe2fe307968 282 #endif
mbedalvaro 0:3fe2fe307968 283
mbedalvaro 0:3fe2fe307968 284 //*******Correction using LINEAR approximation
mbedalvaro 0:3fe2fe307968 285 #ifdef LUT_LINEAR
mbedalvaro 0:3fe2fe307968 286 unsigned short X = x >> LUT_BITS_SHIFT; //mirror "x" is 12bits, LUT "X" needs 4bits when lut is 17x17
mbedalvaro 0:3fe2fe307968 287 unsigned short Y = y >> LUT_BITS_SHIFT; //mirror "y" is 12bits, LUT "Y" needs 4bits when lut is 17x17
mbedalvaro 0:3fe2fe307968 288 float dx = 1.0*(x & LUT_BITS_MASK)/(LUT_BITS_MASK+1); //weight to apply on X (mask with 255 and norm)
mbedalvaro 0:3fe2fe307968 289 float dy = 1.0*(y & LUT_BITS_MASK)/(LUT_BITS_MASK+1); //weight to apply on Y (mask with 255 and norm)
mbedalvaro 0:3fe2fe307968 290 float linearLUT, dzx, dzy;
mbedalvaro 0:3fe2fe307968 291
mbedalvaro 0:3fe2fe307968 292 if(dx>dy){ //if the position is on the "top-right" triangle
mbedalvaro 0:3fe2fe307968 293 dzx = (lut[X+1][Y] - lut[X][Y]) * dx;
mbedalvaro 0:3fe2fe307968 294 dzy = (lut[X+1][Y+1] - lut[X+1][Y]) * dy;
mbedalvaro 0:3fe2fe307968 295 }
mbedalvaro 0:3fe2fe307968 296 else{ //if the position is on the "bottom-left" triangle
mbedalvaro 0:3fe2fe307968 297 dzy = (lut[X][Y+1] - lut[X][Y]) * dy;
mbedalvaro 0:3fe2fe307968 298 dzx = (lut[X+1][Y+1] - lut[X][Y+1]) * dx;
mbedalvaro 0:3fe2fe307968 299 }
mbedalvaro 0:3fe2fe307968 300
mbedalvaro 0:3fe2fe307968 301 //linear approximation of the Look-Up Table at the position (x,y):
mbedalvaro 0:3fe2fe307968 302 linearLUT = lut[X][Y] + dzx + dzy;
mbedalvaro 0:3fe2fe307968 303 return 2.0* NB_SCANS * lockin_read() / linearLUT; // 2 * NB_SCANS is the number of recorded sample added to one position of the LUT (scan is performed twice: left-right and right-left)
mbedalvaro 0:3fe2fe307968 304
mbedalvaro 0:3fe2fe307968 305 #endif
mbedalvaro 0:3fe2fe307968 306
mbedalvaro 0:3fe2fe307968 307 //*******No corrections, just return the value divided by 4096 (this means we are assuming that the surface is everywhere perfectly reflective - we supposedly get the max value always)
mbedalvaro 0:3fe2fe307968 308 #ifdef NO_LUT
mbedalvaro 0:3fe2fe307968 309 return 1.0* lockin_read()/4096;
mbedalvaro 0:3fe2fe307968 310 #endif
mbedalvaro 0:3fe2fe307968 311
mbedalvaro 0:3fe2fe307968 312 }