Revision 0:2d546112b0b8, committed 2015-03-13

Comitter:

ng3600

Date:

Fri Mar 13 06:26:35 2015 +0000

Commit message:

LineScan library to interface with the line scanner

Changed in this revision

diff -r 000000000000 -r 2d546112b0b8 LineScan.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LineScan.cpp	Fri Mar 13 06:26:35 2015 +0000
@@ -0,0 +1,67 @@
+/*
+AnalogIn cam1(CAM1_IN);
+DigitalOut camSi(CAM_SI);
+DigitalOut camClk(CAM_CLK); // Definining camera pins. 
+*/
+#include "LineScan.h"
+
+uint16_t read1Bit(AnalogIn cam, DigitalOut *camClk){
+    uint16_t pixel;
+    
+    //read pixel n
+    pixel = cam.read_u16();
+    
+    //clock pulse for next pixel n + 1
+    *camClk = 1;
+    *camClk = 0;
+    
+    return pixel;  //return result as an uint16_t (16 bit integer)
+}
+
+void startRead(DigitalOut *camSi, DigitalOut *camClk){
+    //pulse first clock cycle and start integral pin
+    *camSi = 1;
+    *camClk = 1;
+    *camSi = 0;
+    *camClk = 0;
+}
+
+int processFn(uint16_t *array, int arraySz){
+    int lineCtr = 0;
+    
+    //replace with cross correlation function or averaging function
+    //currently returns index of smallest item
+    //skip 15 indices on both ends as they are noisy
+    for(int i = 16; i < arraySz - 15; i++){
+        if(array[i] < array[lineCtr])
+            lineCtr = i;
+    }
+    
+    return lineCtr;
+}
+
+//call after integration time is done, returns index of array line is expected to be at
+int getLinePos(AnalogIn cam, DigitalOut *camSi, DigitalOut *camClk){
+    uint16_t lineAry[NUM_PIX];
+    int position;
+    
+    //read 
+    startRead(camSi, camClk);
+    for(int i = 0; i < NUM_PIX; i++){
+        lineAry[i] = read1Bit(cam, camClk);
+    }
+    
+    //process line scan data
+    position  = processFn(lineAry, NUM_PIX);
+    
+    return position;
+}
+
+/*
+sample call (handler thread):
+
+while(1){
+   linePos  = getLinePos(cameraIn1, si, clk);   //volatile linePos, replace with steering angle and read 2 cameras?
+   Thread::wait(14);    //sleep for 14 us
+}
+*/
\ No newline at end of file

diff -r 000000000000 -r 2d546112b0b8 LineScan.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LineScan.h	Fri Mar 13 06:26:35 2015 +0000
@@ -0,0 +1,9 @@
+#include "mbed.h"
+#include "rtos.h"
+
+#define NUM_PIX 128
+
+uint16_t read1Bit(AnalogIn cam, DigitalOut *camClk);
+void startRead(DigitalOut *camSi, DigitalOut *camClk);
+int processFn(uint16_t *array, int arraySz);
+int getLinePos(AnalogIn cam, DigitalOut *camSi, DigitalOut *camClk);
\ No newline at end of file