Program to read out a Hamamatsu S9226 linear photodiode array. Program averages each pixel's value over a number of scans to reduce noise

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Comitter:
marcbax
Date:
Fri Nov 26 20:35:49 2010 +0000
Commit message:

Changed in this revision

TextLCD.cpp Show annotated file Show diff for this revision Revisions of this file
TextLCD.h Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
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