Alvaro Cassinelli / Mbed 2 deprecated laserUI

Laser Sensing Display for UI interfaces in the real world

Dependencies:   mbed

Fork of skinGames_forktest by Alvaro Cassinelli

hardwareIO/hardwareIO.cpp@23:bf666fcc61bc, 2012-06-13 (annotated)

Committer:
mbedalvaro
Date:
Wed Jun 13 10:09:41 2012 +0000
Revision:
23:bf666fcc61bc
Parent:
22:d87317d7ca91
Child:
24:4e52031a495b
- added function to check laser power ; - but there seems to be a problem on the green laser control... at least on bouncing mode. The way the green color is set is wrong too - not per blob color?

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbedalvaro 0:345b3bc7a0ea 1 #include "hardwareIO.h"
mbedalvaro 0:345b3bc7a0ea 2
mbedalvaro 0:345b3bc7a0ea 3 HardwareIO IO; // preintantiation of cross-file global object IO
mbedalvaro 0:345b3bc7a0ea 4
mbedalvaro 0:345b3bc7a0ea 5 // -------------------------------------- (0) SETUP ALL IO (call this in the setup() function in main program)
mbedalvaro 0:345b3bc7a0ea 6
mbedalvaro 0:345b3bc7a0ea 7 Serial pc(USBTX, USBRX); // tx, rx
mbedalvaro 0:345b3bc7a0ea 8 LocalFileSystem local("local"); // Create the local filesystem under the name "local"
mbedalvaro 0:345b3bc7a0ea 9
mbedalvaro 0:345b3bc7a0ea 10 SPI spiDAC(MOSI_PIN, MISO_PIN, SCK_PIN); // mosi, miso, sclk
mbedalvaro 0:345b3bc7a0ea 11 DigitalOut csDAC(CS_DAC_MIRRORS);
mbedalvaro 0:345b3bc7a0ea 12
mbedalvaro 23:bf666fcc61bc 13 AnalogIn ain(POT_ANALOG_INPUT);
mbedalvaro 23:bf666fcc61bc 14
mbedalvaro 23:bf666fcc61bc 15 DigitalOut Laser_Red(LASER_RED_PIN); // NOTE: this is NOT the lock in sensing laser (actually, not used yet)
mbedalvaro 0:345b3bc7a0ea 16 DigitalOut Laser_Green(LASER_GREEN_PIN);
mbedalvaro 0:345b3bc7a0ea 17 DigitalOut Laser_Blue(LASER_BLUE_PIN);
mbedalvaro 0:345b3bc7a0ea 18
mbedalvaro 0:345b3bc7a0ea 19 void HardwareIO::init(void) {
mbedalvaro 23:bf666fcc61bc 20 Laser_Red = 0; // note: this is not the lockin-laser!
mbedalvaro 0:345b3bc7a0ea 21 Laser_Green = 0;
mbedalvaro 0:345b3bc7a0ea 22 Laser_Blue = 0;
mbedalvaro 0:345b3bc7a0ea 23
mbedalvaro 0:345b3bc7a0ea 24 //Serial Communication setup:
mbedalvaro 14:0fc33a3a7b4b 25 pc.baud(115200);//
mbedalvaro 14:0fc33a3a7b4b 26 // pc.baud(921600);//115200);//
mbedalvaro 0:345b3bc7a0ea 27
mbedalvaro 0:345b3bc7a0ea 28 // Setup for lock-in amplifier and pwm references:
mbedalvaro 0:345b3bc7a0ea 29 lockin.init();
mbedalvaro 0:345b3bc7a0ea 30
mbedalvaro 0:345b3bc7a0ea 31 // Setup the spi for 8 bit data, high steady state clock,
mbedalvaro 0:345b3bc7a0ea 32 // second edge capture, with a 10MHz clock rate
mbedalvaro 0:345b3bc7a0ea 33 csDAC = 1;
mbedalvaro 0:345b3bc7a0ea 34 spiDAC.format(16,0);
mbedalvaro 0:345b3bc7a0ea 35 spiDAC.frequency(16000000);
mbedalvaro 0:345b3bc7a0ea 36
mbedalvaro 0:345b3bc7a0ea 37 // default initial mirror position:
mbedalvaro 0:345b3bc7a0ea 38 writeOutX(CENTER_AD_MIRROR_X);
mbedalvaro 0:345b3bc7a0ea 39 writeOutY(CENTER_AD_MIRROR_Y);
mbedalvaro 0:345b3bc7a0ea 40
mbedalvaro 0:345b3bc7a0ea 41 // Load LUT table:
mbedalvaro 0:345b3bc7a0ea 42 setLUT();
mbedalvaro 0:345b3bc7a0ea 43 }
mbedalvaro 0:345b3bc7a0ea 44
mbedalvaro 0:345b3bc7a0ea 45 //write on the first DAC, output A (mirror X)
mbedalvaro 10:6f8e48dca1bd 46 void HardwareIO::writeOutX(unsigned short value){
mbedalvaro 0:345b3bc7a0ea 47 if(value > MAX_AD_MIRRORS) value = MAX_AD_MIRRORS;
mbedalvaro 0:345b3bc7a0ea 48 if(value < MIN_AD_MIRRORS) value = MIN_AD_MIRRORS;
mbedalvaro 0:345b3bc7a0ea 49
mbedalvaro 0:345b3bc7a0ea 50 value |= 0x7000;
mbedalvaro 0:345b3bc7a0ea 51 value &= 0x7FFF;
mbedalvaro 0:345b3bc7a0ea 52
mbedalvaro 0:345b3bc7a0ea 53 csDAC = 0;
mbedalvaro 0:345b3bc7a0ea 54 spiDAC.write(value);
mbedalvaro 0:345b3bc7a0ea 55 csDAC = 1;
mbedalvaro 0:345b3bc7a0ea 56 }
mbedalvaro 0:345b3bc7a0ea 57
mbedalvaro 0:345b3bc7a0ea 58 //write on the first DAC, output B (mirror Y)
mbedalvaro 10:6f8e48dca1bd 59 void HardwareIO::writeOutY(unsigned short value){
mbedalvaro 0:345b3bc7a0ea 60 if(value > MAX_AD_MIRRORS) value = MAX_AD_MIRRORS;
mbedalvaro 0:345b3bc7a0ea 61 if(value < MIN_AD_MIRRORS) value = MIN_AD_MIRRORS;
mbedalvaro 0:345b3bc7a0ea 62
mbedalvaro 0:345b3bc7a0ea 63 value |= 0xF000;
mbedalvaro 0:345b3bc7a0ea 64 value &= 0xFFFF;
mbedalvaro 0:345b3bc7a0ea 65
mbedalvaro 0:345b3bc7a0ea 66 csDAC = 0;
mbedalvaro 0:345b3bc7a0ea 67 spiDAC.write(value);
mbedalvaro 0:345b3bc7a0ea 68 csDAC = 1;
mbedalvaro 0:345b3bc7a0ea 69 }
mbedalvaro 0:345b3bc7a0ea 70
mbedalvaro 0:345b3bc7a0ea 71 void HardwareIO::setRedPower(int powerValue){
mbedalvaro 0:345b3bc7a0ea 72 if(powerValue > 0){
mbedalvaro 0:345b3bc7a0ea 73 lockin.setLaserPower(true);
mbedalvaro 0:345b3bc7a0ea 74 }
mbedalvaro 0:345b3bc7a0ea 75 else{
mbedalvaro 0:345b3bc7a0ea 76 lockin.setLaserPower(false);
mbedalvaro 0:345b3bc7a0ea 77 }
mbedalvaro 0:345b3bc7a0ea 78 }
mbedalvaro 0:345b3bc7a0ea 79 void HardwareIO::setGreenPower(int powerValue){
mbedalvaro 0:345b3bc7a0ea 80 if(powerValue > 0){
mbedalvaro 0:345b3bc7a0ea 81 Laser_Green = 1;
mbedalvaro 0:345b3bc7a0ea 82 }
mbedalvaro 0:345b3bc7a0ea 83 else{
mbedalvaro 0:345b3bc7a0ea 84 Laser_Green = 0;
mbedalvaro 0:345b3bc7a0ea 85 }
mbedalvaro 0:345b3bc7a0ea 86 }
mbedalvaro 0:345b3bc7a0ea 87 void HardwareIO::setBluePower(int powerValue){
mbedalvaro 0:345b3bc7a0ea 88 if(powerValue > 0){
mbedalvaro 0:345b3bc7a0ea 89 Laser_Blue = 1;
mbedalvaro 0:345b3bc7a0ea 90 }
mbedalvaro 0:345b3bc7a0ea 91 else{
mbedalvaro 0:345b3bc7a0ea 92 Laser_Blue = 0;
mbedalvaro 0:345b3bc7a0ea 93 }
mbedalvaro 0:345b3bc7a0ea 94 }
mbedalvaro 0:345b3bc7a0ea 95
mbedalvaro 23:bf666fcc61bc 96 void HardwareIO::setRGBPower(unsigned char color) {
mbedalvaro 23:bf666fcc61bc 97 lockin.setLaserPower(color&0x04>0? false : true);
mbedalvaro 0:345b3bc7a0ea 98 Laser_Green=(color&0x02)>>1;
mbedalvaro 23:bf666fcc61bc 99 Laser_Blue =color&0x01;
mbedalvaro 0:345b3bc7a0ea 100 }
mbedalvaro 0:345b3bc7a0ea 101
mbedalvaro 22:d87317d7ca91 102 void HardwareIO::showLimitsMirrors(int times) {
mbedalvaro 22:d87317d7ca91 103 unsigned short pointsPerLine=100;
mbedalvaro 22:d87317d7ca91 104
mbedalvaro 22:d87317d7ca91 105 for (int repeat=0; repeat<times; repeat++) {
mbedalvaro 22:d87317d7ca91 106
mbedalvaro 22:d87317d7ca91 107 int shiftX = (MAX_AD_MIRRORS - MIN_AD_MIRRORS) / pointsPerLine;
mbedalvaro 22:d87317d7ca91 108 int shiftY = (MAX_AD_MIRRORS - MIN_AD_MIRRORS) / pointsPerLine;
mbedalvaro 22:d87317d7ca91 109
mbedalvaro 22:d87317d7ca91 110 writeOutX(MIN_AD_MIRRORS);writeOutY(MIN_AD_MIRRORS);
mbedalvaro 22:d87317d7ca91 111 for(int j=0; j<pointsPerLine; j++){
mbedalvaro 22:d87317d7ca91 112 wait_us(200);//delay between each points
mbedalvaro 22:d87317d7ca91 113 writeOutY(j*shiftY + MIN_AD_MIRRORS);
mbedalvaro 22:d87317d7ca91 114 }
mbedalvaro 22:d87317d7ca91 115
mbedalvaro 22:d87317d7ca91 116 writeOutX(MIN_AD_MIRRORS);writeOutY(MAX_AD_MIRRORS);
mbedalvaro 22:d87317d7ca91 117 for(int j=0; j<pointsPerLine; j++) {
mbedalvaro 22:d87317d7ca91 118 wait_us(200);//delay between each points
mbedalvaro 22:d87317d7ca91 119 writeOutX(j*shiftX + MAX_AD_MIRRORS);
mbedalvaro 22:d87317d7ca91 120 }
mbedalvaro 22:d87317d7ca91 121
mbedalvaro 22:d87317d7ca91 122 writeOutX(MAX_AD_MIRRORS);writeOutY(MAX_AD_MIRRORS);
mbedalvaro 22:d87317d7ca91 123 for(int j=0; j<pointsPerLine; j++) {
mbedalvaro 22:d87317d7ca91 124 wait_us(200);//delay between each points
mbedalvaro 22:d87317d7ca91 125 writeOutY(-j*shiftX + MAX_AD_MIRRORS);
mbedalvaro 22:d87317d7ca91 126 }
mbedalvaro 22:d87317d7ca91 127
mbedalvaro 22:d87317d7ca91 128 writeOutX(MAX_AD_MIRRORS);writeOutY(MIN_AD_MIRRORS);
mbedalvaro 22:d87317d7ca91 129 for(int j=0; j<pointsPerLine; j++) {
mbedalvaro 22:d87317d7ca91 130 wait_us(200);//delay between each points
mbedalvaro 22:d87317d7ca91 131 writeOutX(-j*shiftX + MAX_AD_MIRRORS);
mbedalvaro 22:d87317d7ca91 132 }
mbedalvaro 22:d87317d7ca91 133
mbedalvaro 22:d87317d7ca91 134 }
mbedalvaro 22:d87317d7ca91 135 }
mbedalvaro 22:d87317d7ca91 136
mbedalvaro 10:6f8e48dca1bd 137 void HardwareIO::scan_serial(unsigned short pointsPerLine){
mbedalvaro 0:345b3bc7a0ea 138 //scan the total surface with a custom resolution
mbedalvaro 0:345b3bc7a0ea 139 //send the lockin value for each point as a byte on the serial port to the PC
mbedalvaro 0:345b3bc7a0ea 140 //use "scanSLP_save" to see the data on processing
mbedalvaro 0:345b3bc7a0ea 141
mbedalvaro 0:345b3bc7a0ea 142
mbedalvaro 0:345b3bc7a0ea 143 int shiftX = (MAX_AD_MIRRORS - MIN_AD_MIRRORS) / pointsPerLine;
mbedalvaro 0:345b3bc7a0ea 144 int shiftY = (MAX_AD_MIRRORS - MIN_AD_MIRRORS) / pointsPerLine;
mbedalvaro 0:345b3bc7a0ea 145
mbedalvaro 0:345b3bc7a0ea 146 for(int j=0; j<pointsPerLine; j++){
mbedalvaro 0:345b3bc7a0ea 147 writeOutX(MIN_AD_MIRRORS);
mbedalvaro 0:345b3bc7a0ea 148 writeOutY(j*shiftY + MIN_AD_MIRRORS);
mbedalvaro 0:345b3bc7a0ea 149
mbedalvaro 0:345b3bc7a0ea 150 wait_us(300);//begining of line delay
mbedalvaro 0:345b3bc7a0ea 151 for(int i=0; i<pointsPerLine; i++){
mbedalvaro 0:345b3bc7a0ea 152 writeOutX(i*shiftX + MIN_AD_MIRRORS);
mbedalvaro 0:345b3bc7a0ea 153
mbedalvaro 14:0fc33a3a7b4b 154 wait_us(200);//delay between each points
mbedalvaro 10:6f8e48dca1bd 155
mbedalvaro 10:6f8e48dca1bd 156 // SEND A VALUE BETWEEN 0 and 255:
mbedalvaro 0:345b3bc7a0ea 157 pc.putc(int(255.0*lockin.getMedianValue()/4095));//printf("%dL",int(valueLockin*255));//pc.putc(int(lockin*255));//
mbedalvaro 0:345b3bc7a0ea 158 }
mbedalvaro 0:345b3bc7a0ea 159 }
mbedalvaro 0:345b3bc7a0ea 160 }
mbedalvaro 0:345b3bc7a0ea 161
mbedalvaro 0:345b3bc7a0ea 162 //load Look-up Table from LUT.TXT file
mbedalvaro 0:345b3bc7a0ea 163 //or create the file with scanLUT() if not existing.
mbedalvaro 0:345b3bc7a0ea 164 void HardwareIO::setLUT(){
mbedalvaro 0:345b3bc7a0ea 165
mbedalvaro 0:345b3bc7a0ea 166 FILE *fp = fopen(LUT_FILENAME, "r"); // Open file on the local file system for writing
mbedalvaro 0:345b3bc7a0ea 167 if(fp){
mbedalvaro 0:345b3bc7a0ea 168 //load the file into the lut table; keep the SAME resolution!
mbedalvaro 0:345b3bc7a0ea 169 fread(lut,sizeof(uint16),LUT_RESOLUTION*LUT_RESOLUTION,fp);
mbedalvaro 0:345b3bc7a0ea 170 fclose(fp);
mbedalvaro 0:345b3bc7a0ea 171 }
mbedalvaro 0:345b3bc7a0ea 172 else{
mbedalvaro 0:345b3bc7a0ea 173 //fclose(fp);
mbedalvaro 0:345b3bc7a0ea 174 //if the file "LUT.TXT" doesn't exist, create one with scanLUT()
mbedalvaro 0:345b3bc7a0ea 175 lockin.setLaserPower(true);
mbedalvaro 0:345b3bc7a0ea 176 scanLUT();
mbedalvaro 0:345b3bc7a0ea 177 }
mbedalvaro 0:345b3bc7a0ea 178
mbedalvaro 0:345b3bc7a0ea 179 }
mbedalvaro 0:345b3bc7a0ea 180
mbedalvaro 0:345b3bc7a0ea 181 //scan the total surface with a fixed 2^x resolution
mbedalvaro 0:345b3bc7a0ea 182 //create the Look-Up Table used to "flatten" the scan according to the position
mbedalvaro 0:345b3bc7a0ea 183 //
mbedalvaro 0:345b3bc7a0ea 184 //To Do: maybe detect high frequency to be sure the area is clean and empty?
mbedalvaro 0:345b3bc7a0ea 185 void HardwareIO::scanLUT(){
mbedalvaro 0:345b3bc7a0ea 186
mbedalvaro 0:345b3bc7a0ea 187 //reset lut table
mbedalvaro 0:345b3bc7a0ea 188 for(int j=0; j<LUT_RESOLUTION; j++){
mbedalvaro 0:345b3bc7a0ea 189 for(int i=0; i<LUT_RESOLUTION; i++){
mbedalvaro 0:345b3bc7a0ea 190 lut[i][j] =0;
mbedalvaro 0:345b3bc7a0ea 191 }
mbedalvaro 0:345b3bc7a0ea 192 }
mbedalvaro 0:345b3bc7a0ea 193
mbedalvaro 0:345b3bc7a0ea 194 int delayScanning = 300; //in us
mbedalvaro 0:345b3bc7a0ea 195
mbedalvaro 0:345b3bc7a0ea 196 //define the distance between each points (from 0 to 4096) and the offset (here 0)
mbedalvaro 0:345b3bc7a0ea 197 float shiftX = 1.0*(MAX_AD_MIRRORS - MIN_AD_MIRRORS) / (LUT_RESOLUTION-1);
mbedalvaro 0:345b3bc7a0ea 198 float shiftY = 1.0*(MAX_AD_MIRRORS - MIN_AD_MIRRORS) / (LUT_RESOLUTION-1);
mbedalvaro 0:345b3bc7a0ea 199 float offsetX = MIN_AD_MIRRORS;
mbedalvaro 0:345b3bc7a0ea 200 float offsetY = MIN_AD_MIRRORS;
mbedalvaro 0:345b3bc7a0ea 201
mbedalvaro 0:345b3bc7a0ea 202 //move the mirrors to the first position
mbedalvaro 0:345b3bc7a0ea 203 writeOutX(MAX_AD_MIRRORS);writeOutY(MIN_AD_MIRRORS);
mbedalvaro 0:345b3bc7a0ea 204 wait_us(500);
mbedalvaro 0:345b3bc7a0ea 205
mbedalvaro 0:345b3bc7a0ea 206 float x, y;
mbedalvaro 0:345b3bc7a0ea 207
mbedalvaro 10:6f8e48dca1bd 208 //scan the surface NB_SCANS times
mbedalvaro 0:345b3bc7a0ea 209 //the total value in lut[i][j] shouldn't exceed uint16 !!!
mbedalvaro 10:6f8e48dca1bd 210 for(int loop=0; loop<NB_SCANS; loop++){
mbedalvaro 0:345b3bc7a0ea 211 for(int j=0; j<LUT_RESOLUTION; j++){
mbedalvaro 0:345b3bc7a0ea 212 y = shiftY*j + offsetY ;
mbedalvaro 0:345b3bc7a0ea 213 writeOutY(int(y));
mbedalvaro 0:345b3bc7a0ea 214 //scan from right to left
mbedalvaro 0:345b3bc7a0ea 215 for(int i=LUT_RESOLUTION-1; i>=0; i--){
mbedalvaro 0:345b3bc7a0ea 216 x = shiftX*i + offsetX;
mbedalvaro 0:345b3bc7a0ea 217 writeOutX(int(x));
mbedalvaro 0:345b3bc7a0ea 218 wait_us(delayScanning);
mbedalvaro 0:345b3bc7a0ea 219 lut[i][j] += lockin_read();
mbedalvaro 0:345b3bc7a0ea 220 }
mbedalvaro 0:345b3bc7a0ea 221 //re-scan from left to right
mbedalvaro 0:345b3bc7a0ea 222 for(int i=0; i<LUT_RESOLUTION; i++){
mbedalvaro 0:345b3bc7a0ea 223 x = shiftX*i + offsetX;
mbedalvaro 0:345b3bc7a0ea 224 writeOutX(int(x));
mbedalvaro 0:345b3bc7a0ea 225 wait_us(delayScanning);
mbedalvaro 0:345b3bc7a0ea 226 lut[i][j] += lockin_read();
mbedalvaro 0:345b3bc7a0ea 227 }
mbedalvaro 0:345b3bc7a0ea 228 }
mbedalvaro 0:345b3bc7a0ea 229 }
mbedalvaro 0:345b3bc7a0ea 230
mbedalvaro 0:345b3bc7a0ea 231
mbedalvaro 0:345b3bc7a0ea 232 //save tab in file
mbedalvaro 0:345b3bc7a0ea 233 FILE *fp;
mbedalvaro 0:345b3bc7a0ea 234 #ifdef LUT_FILENAME
mbedalvaro 0:345b3bc7a0ea 235 fp = fopen(LUT_FILENAME, "w"); // Open file on the local file system for writing
mbedalvaro 0:345b3bc7a0ea 236 fwrite(lut,sizeof(uint16),LUT_RESOLUTION*LUT_RESOLUTION,fp);
mbedalvaro 0:345b3bc7a0ea 237 fclose(fp); //close the file (the mBed will appear connected again)
mbedalvaro 0:345b3bc7a0ea 238 #endif
mbedalvaro 0:345b3bc7a0ea 239
mbedalvaro 0:345b3bc7a0ea 240 #ifdef LUT_H_FILENAME
mbedalvaro 22:d87317d7ca91 241 //save tab in Human readable file (not used by the program, this is just for checking)
mbedalvaro 22:d87317d7ca91 242 // NOTE: we divide the content of the lut table by NB_SCANS, for easy reading (values should be between 0-4095)
mbedalvaro 0:345b3bc7a0ea 243 fp = fopen(LUT_H_FILENAME, "w"); // Open file on the local file system for writing
mbedalvaro 0:345b3bc7a0ea 244 fprintf(fp, "scan resolution: %d x %d\r\n",LUT_RESOLUTION, LUT_RESOLUTION);
mbedalvaro 0:345b3bc7a0ea 245 for(int j=0; j<LUT_RESOLUTION; j++){
mbedalvaro 0:345b3bc7a0ea 246 for(int i=0; i<LUT_RESOLUTION; i++){
mbedalvaro 23:bf666fcc61bc 247 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 0:345b3bc7a0ea 248 }
mbedalvaro 0:345b3bc7a0ea 249 }
mbedalvaro 0:345b3bc7a0ea 250 fclose(fp); //close the file (the mBed will appear connected again)
mbedalvaro 0:345b3bc7a0ea 251 #endif
mbedalvaro 0:345b3bc7a0ea 252
mbedalvaro 0:345b3bc7a0ea 253 }
mbedalvaro 0:345b3bc7a0ea 254
mbedalvaro 0:345b3bc7a0ea 255
mbedalvaro 10:6f8e48dca1bd 256 //Return the lockin value "corrected with the Look-UpTable" - this means a RATIO between two reflectivities (and normally, this is <1).
mbedalvaro 10:6f8e48dca1bd 257 float HardwareIO::lockInCorrectedValue(unsigned short x, unsigned short y){
mbedalvaro 0:345b3bc7a0ea 258 //*******Correction using DIRECT approximation
mbedalvaro 0:345b3bc7a0ea 259 #ifdef LUT_DIRECT
mbedalvaro 10:6f8e48dca1bd 260 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 22:d87317d7ca91 261 #endif
mbedalvaro 22:d87317d7ca91 262
mbedalvaro 0:345b3bc7a0ea 263 //*******Correction using BILINEAR approximation
mbedalvaro 0:345b3bc7a0ea 264 #ifdef LUT_BILINEAR
mbedalvaro 14:0fc33a3a7b4b 265 unsigned short X = x >> LUT_BITS_SHIFT; //mirror "x" is 12bits, LUT "X" needs 4bits when lut is 17x17
mbedalvaro 14:0fc33a3a7b4b 266 unsigned short Y = y >> LUT_BITS_SHIFT; //mirror "y" is 12bits, LUT "Y" needs 4bits when lut is 17x17
mbedalvaro 0:345b3bc7a0ea 267 float dx = 1.0*(x & LUT_BITS_MASK)/(LUT_BITS_MASK+1); //weight to apply on X (mask with 255 and norm)
mbedalvaro 0:345b3bc7a0ea 268 float dy = 1.0*(y & LUT_BITS_MASK)/(LUT_BITS_MASK+1); //weight to apply on Y (mask with 255 and norm)
mbedalvaro 0:345b3bc7a0ea 269
mbedalvaro 0:345b3bc7a0ea 270 //Wheighted mean approximation of the Look-Up Table at the position (x,y):
mbedalvaro 0:345b3bc7a0ea 271 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 0:345b3bc7a0ea 272
mbedalvaro 22:d87317d7ca91 273 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 22:d87317d7ca91 274 #endif
mbedalvaro 22:d87317d7ca91 275
mbedalvaro 0:345b3bc7a0ea 276 //*******Correction using LINEAR approximation
mbedalvaro 0:345b3bc7a0ea 277 #ifdef LUT_LINEAR
mbedalvaro 14:0fc33a3a7b4b 278 unsigned short X = x >> LUT_BITS_SHIFT; //mirror "x" is 12bits, LUT "X" needs 4bits when lut is 17x17
mbedalvaro 14:0fc33a3a7b4b 279 unsigned short Y = y >> LUT_BITS_SHIFT; //mirror "y" is 12bits, LUT "Y" needs 4bits when lut is 17x17
mbedalvaro 0:345b3bc7a0ea 280 float dx = 1.0*(x & LUT_BITS_MASK)/(LUT_BITS_MASK+1); //weight to apply on X (mask with 255 and norm)
mbedalvaro 0:345b3bc7a0ea 281 float dy = 1.0*(y & LUT_BITS_MASK)/(LUT_BITS_MASK+1); //weight to apply on Y (mask with 255 and norm)
mbedalvaro 0:345b3bc7a0ea 282 float linearLUT, dzx, dzy;
mbedalvaro 0:345b3bc7a0ea 283
mbedalvaro 0:345b3bc7a0ea 284 if(dx>dy){ //if the position is on the "top-right" triangle
mbedalvaro 0:345b3bc7a0ea 285 dzx = (lut[X+1][Y] - lut[X][Y]) * dx;
mbedalvaro 0:345b3bc7a0ea 286 dzy = (lut[X+1][Y+1] - lut[X+1][Y]) * dy;
mbedalvaro 0:345b3bc7a0ea 287 }
mbedalvaro 0:345b3bc7a0ea 288 else{ //if the position is on the "bottom-left" triangle
mbedalvaro 0:345b3bc7a0ea 289 dzy = (lut[X][Y+1] - lut[X][Y]) * dy;
mbedalvaro 0:345b3bc7a0ea 290 dzx = (lut[X+1][Y+1] - lut[X][Y+1]) * dx;
mbedalvaro 0:345b3bc7a0ea 291 }
mbedalvaro 0:345b3bc7a0ea 292
mbedalvaro 0:345b3bc7a0ea 293 //linear approximation of the Look-Up Table at the position (x,y):
mbedalvaro 0:345b3bc7a0ea 294 linearLUT = lut[X][Y] + dzx + dzy;
mbedalvaro 10:6f8e48dca1bd 295 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 0:345b3bc7a0ea 296
mbedalvaro 22:d87317d7ca91 297 #endif
mbedalvaro 22:d87317d7ca91 298
mbedalvaro 22:d87317d7ca91 299 //*******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 22:d87317d7ca91 300 #ifdef NO_LUT
mbedalvaro 10:6f8e48dca1bd 301 return 1.0* lockin_read()/4096;
mbedalvaro 22:d87317d7ca91 302 #endif
mbedalvaro 22:d87317d7ca91 303
mbedalvaro 0:345b3bc7a0ea 304 }