Program to read out a Hamamatsu S9226 linear photodiode array. Program averages each pixel's value over a number of scans to reduce noise
Revision 0:0a05dbed4fed, committed 2010-11-26
- Comitter:
- marcbax
- Date:
- Fri Nov 26 20:35:49 2010 +0000
- Commit message:
Changed in this revision
diff -r 000000000000 -r 0a05dbed4fed TextLCD.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/TextLCD.cpp Fri Nov 26 20:35:49 2010 +0000 @@ -0,0 +1,159 @@ +/* mbed TextLCD Library, for a 4-bit LCD based on HD44780 + * Copyright (c) 2007-2010, sford + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "TextLCD.h" +#include "mbed.h" + +TextLCD::TextLCD(PinName rs, PinName e, PinName d0, PinName d1, + PinName d2, PinName d3, LCDType type) : _rs(rs), + _e(e), _d(d0, d1, d2, d3), + _type(type) { + + _e = 1; + _rs = 0; // command mode + + wait(0.015); // Wait 15ms to ensure powered up + + // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus) + for (int i=0; i<3; i++) { + writeByte(0x3); + wait(0.00164); // this command takes 1.64ms, so wait for it + } + writeByte(0x2); // 4-bit mode + wait(0.000040f); // most instructions take 40us + + writeCommand(0x28); // Function set 001 BW N F - - + writeCommand(0x0C); + writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes + cls(); +} + +void TextLCD::character(int column, int row, int c) { + int a = address(column, row); + writeCommand(a); + writeData(c); +} + +void TextLCD::cls() { + writeCommand(0x01); // cls, and set cursor to 0 + wait(0.00164f); // This command takes 1.64 ms + locate(0, 0); +} + +void TextLCD::locate(int column, int row) { + _column = column; + _row = row; +} + +int TextLCD::_putc(int value) { + if (value == '\n') { + _column = 0; + _row++; + if (_row >= rows()) { + _row = 0; + } + } else { + character(_column, _row, value); + _column++; + if (_column >= columns()) { + _column = 0; + _row++; + if (_row >= rows()) { + _row = 0; + } + } + } + return value; +} + +int TextLCD::_getc() { + return -1; +} + +void TextLCD::writeByte(int value) { + _d = value >> 4; + wait(0.000040f); // most instructions take 40us + _e = 0; + wait(0.000040f); + _e = 1; + _d = value >> 0; + wait(0.000040f); + _e = 0; + wait(0.000040f); // most instructions take 40us + _e = 1; +} + +void TextLCD::writeCommand(int command) { + _rs = 0; + writeByte(command); +} + +void TextLCD::writeData(int data) { + _rs = 1; + writeByte(data); +} + +int TextLCD::address(int column, int row) { + switch (_type) { + case LCD20x4: + switch (row) { + case 0: + return 0x80 + column; + case 1: + return 0xc0 + column; + case 2: + return 0x94 + column; + case 3: + return 0xd4 + column; + } + case LCD16x2B: + return 0x80 + (row * 40) + column; + case LCD16x2: + case LCD20x2: + default: + return 0x80 + (row * 0x40) + column; + } +} + +int TextLCD::columns() { + switch (_type) { + case LCD20x4: + case LCD20x2: + return 20; + case LCD16x2: + case LCD16x2B: + default: + return 16; + } +} + +int TextLCD::rows() { + switch (_type) { + case LCD20x4: + return 4; + case LCD16x2: + case LCD16x2B: + case LCD20x2: + default: + return 2; + } +}
diff -r 000000000000 -r 0a05dbed4fed TextLCD.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/TextLCD.h Fri Nov 26 20:35:49 2010 +0000 @@ -0,0 +1,111 @@ +/* mbed TextLCD Library, for a 4-bit LCD based on HD44780 + * Copyright (c) 2007-2010, sford + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#ifndef MBED_TEXTLCD_H +#define MBED_TEXTLCD_H + +#include "mbed.h" + +/** A TextLCD interface for driving 4-bit HD44780-based LCDs + * + * Currently supports 16x2, 20x2 and 20x4 panels + * + * @code + * #include "mbed.h" + * #include "TextLCD.h" + * + * TextLCD lcd(p10, p12, p15, p16, p29, p30); // rs, e, d0-d3 + * + * int main() { + * lcd.printf("Hello World!\n"); + * } + * @endcode + */ +class TextLCD : public Stream { +public: + + /** LCD panel format */ + enum LCDType { + LCD16x2 /**< 16x2 LCD panel (default) */ + , LCD16x2B /**< 16x2 LCD panel alternate addressing */ + , LCD20x2 /**< 20x2 LCD panel */ + , LCD20x4 /**< 20x4 LCD panel */ + }; + + /** Create a TextLCD interface + * + * @param rs Instruction/data control line + * @param e Enable line (clock) + * @param d0-d3 Data lines + * @param type Sets the panel size/addressing mode (default = LCD16x2) + */ + TextLCD(PinName rs, PinName e, PinName d0, PinName d1, PinName d2, PinName d3, LCDType type = LCD16x2); + +#if DOXYGEN_ONLY + /** Write a character to the LCD + * + * @param c The character to write to the display + */ + int putc(int c); + + /** Write a formated string to the LCD + * + * @param format A printf-style format string, followed by the + * variables to use in formating the string. + */ + int printf(const char* format, ...); +#endif + + /** Locate to a screen column and row + * + * @param column The horizontal position from the left, indexed from 0 + * @param row The vertical position from the top, indexed from 0 + */ + void locate(int column, int row); + + /** Clear the screen and locate to 0,0 */ + void cls(); + + int rows(); + int columns(); + +protected: + + // Stream implementation functions + virtual int _putc(int value); + virtual int _getc(); + + int address(int column, int row); + void character(int column, int row, int c); + void writeByte(int value); + void writeCommand(int command); + void writeData(int data); + + DigitalOut _rs, _e; + BusOut _d; + LCDType _type; + + int _column; + int _row; +}; + +#endif
diff -r 000000000000 -r 0a05dbed4fed main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Fri Nov 26 20:35:49 2010 +0000 @@ -0,0 +1,107 @@ +#include "mbed.h" +#include "TextLCD.h" + +DigitalOut led1(LED1); //Set up all 4 LEDs for debugging purposes +DigitalOut led2(LED2); +DigitalOut led3(LED3); +DigitalOut led4(LED4); +PwmOut clk(p22); //CLK signal to pin 2 of S9226 +DigitalOut start(p23); //ST signal to pin 4 of S9226 +DigitalOut vgain(p24); //Video gain - 0=high, 1=low +DigitalOut itrcheck(p5); //itrcheck is "1" during A-to-D conversion - debugging purpose +DigitalIn EOS(p17); //EOS signal from pin 7 of S9226 +DigitalIn clkin(p21); //loopback CLK input to count integration time +DigitalIn button1(p14); //Define start/stop button +AnalogIn video(p20); //analog input signal - output from pin 6 on S9226 +InterruptIn trigger(p18); //Trig signal from pin 3 of S9226 +TextLCD lcd(p8, p9, p10, p11, p12, p13); //Define 16 x 2 character LCD +LocalFileSystem local("local"); //Define file system on mbed thumbdrive +int i,j,k, pixvalue, avnumber, avarray, avdiv, clkperiod; +int pixels[1024], avpixels[1024]; + +void readpixel() { //ISR that takes one pixel reading, called on falling flank of "trigger" + itrcheck=1; + pixels[i] = video.read_u16()/avnumber; + i++; + itrcheck=0; +} + +//void counttrig() { +// i++; +//} + +int main() { + clkperiod = 40; //clock period in microseconds - must be a multiple of 10 + clk.period_us(clkperiod); //set clock frequency + clk.write(0.5); //set duty cycle to 50% + start = 1; //set start line "high" + vgain = 1; //set video gain to "low" + + //USER SETTINGS + avnumber = 32; //THIS IS WHERE YOU SET THE NUMBER OF AVERAGES + avdiv = 1024/avnumber; //AVNUMBER MUST BE A POWER OF 2: 2,4,8,16,32,64,128 + //END USER SETTINGS + + itrcheck=0; + lcd.cls(); + while (1) { + lcd.locate(0,0); + lcd.printf("Scan __ of%3i ", avnumber); //Show avnumber on display + while (!button1) //waiting till start button is pressed + lcd.locate(0,1); + lcd.printf("Preparing scans "); + for (i=0; i<1025; i++) { //clear array of average pixel values + avpixels [i] = 0; + } + while (!clkin) //wait for clkin to go "high" - start condition + wait_us(clkperiod/10); //give start pulse of half a clock period, while start is low + start = 0; + wait_us(clkperiod/2); + start = 1; + led1=1; + avarray=0; + i=0; + while (EOS) { //read pixels for dummy scan until EOS goes "low" + trigger.fall(&readpixel); + } + wait(0.1); //0.1s delay to make sure all interrupts are handled + lcd.cls(); //Clear display + for (int j=0; j<avnumber; j++) { //make "avnumber" scans and put average results in the avpixel array + wait(0.1); + lcd.locate(0,0); + lcd.printf("Scan%3i of%3i", j+1, avnumber); + while (!clkin) + wait_us(clkperiod/10); + start = 0; + wait_us(clkperiod/2); + start = 1; + led1 = !led1; //Blink LED1 while scanning + i=0; + while (EOS) { + trigger.fall(&readpixel); + } + wait(0.1); + avarray = 0; + for (int i=0; i<1024; i++) { //divide the result by avnumber then add to sum + avpixels [i] = avpixels [i] + pixels [i]; + avarray = avarray + (pixels[i]/avdiv); //Calculate average value over entire array over this scan + } + lcd.locate(0,1); + lcd.printf("ArrayAv: %6i", avarray); + } + wait(0.1); + led1 = 0; + lcd.locate(0,1); + FILE *fp = fopen("/local/data.csv", "w"); //create or overwrite file "data.csv" on the mbed thumbdrive + lcd.printf("File opened "); + for (int i=10; i<1014; i++) { //write pixel numbers and average values, skipping first and last 10 pixels + fprintf(fp, "%6i,%8i\n", i, avpixels[i]); + } + fclose(fp); //close file "data.csv" so it can be read by the PC + lcd.locate(0,0); + lcd.printf("ArrayAv: %6i", avarray); + lcd.locate(0,1); + lcd.printf("DATA.CSV ready"); + wait(5); + } +}
diff -r 000000000000 -r 0a05dbed4fed mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Fri Nov 26 20:35:49 2010 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/e2ac27c8e93e