JPEGCamera.cpp

00001 /* Arduino JPEGCamera Library
00002  * Copyright 2010 SparkFun Electronic
00003  * Written by Ryan Owens
00004  * Modified by arms22
00005  * Ported to mbed by yamaguch
00006  */
00007 
00008 #include "JPEGCamera.h"
00009 
00010 #define min(x, y) ((x) < (y)) ? (x) : (y)
00011 
00012 const int RESPONSE_TIMEOUT = 500;
00013 const int DATA_TIMEOUT = 1000;
00014 
00015 JPEGCamera::JPEGCamera(PinName tx, PinName rx) : Serial(tx, rx) {
00016     baud(38400);
00017     state = READY;
00018 }
00019 
00020 bool JPEGCamera::setPictureSize(JPEGCamera::PictureSize size, bool doReset) {
00021     char buf[9] = {0x56, 0x00, 0x31, 0x05, 0x04, 0x01, 0x00, 0x19, (char) size};
00022     int ret = sendReceive(buf, sizeof buf, 5);
00023 
00024     if (ret == 5 && buf[0] == 0x76) {
00025         if (doReset)
00026             reset();
00027         return true;
00028     } else
00029         return false;
00030 }
00031 
00032 bool JPEGCamera::isReady() {
00033     return state == READY;
00034 }
00035 
00036 bool JPEGCamera::isProcessing() {
00037     return state == PROCESSING;
00038 }
00039 
00040 bool JPEGCamera::takePicture(char *filename) {
00041     if (state == READY) {
00042         fp = fopen(filename, "wb");
00043         if (fp != 0) {
00044             if (takePicture()) {
00045                 imageSize = getImageSize();
00046                 address = 0;
00047                 state = PROCESSING;
00048             } else {
00049                 fclose(fp);
00050                 printf("takePicture(%s) failed", filename);
00051                 state = ERROR;
00052             }
00053         } else {
00054             printf("fopen() failed");
00055             state = ERROR;
00056         }
00057     }
00058     return state != ERROR;
00059 }
00060 
00061 bool JPEGCamera::processPicture() {
00062     if (state == PROCESSING) {
00063         if (address < imageSize) {
00064             char data[1024];
00065             int size = readData(data, min(sizeof(data), imageSize - address), address);
00066             int ret = fwrite(data, size, 1, fp);
00067             if (ret > 0)
00068                 address += size;
00069             if (ret == 0 || address >= imageSize) {
00070                 stopPictures();
00071                 fclose(fp);
00072                 wait(0.1); // ????
00073                 state = ret > 0 ? READY : ERROR;
00074             }
00075         }
00076     }
00077 
00078     return state == PROCESSING || state == READY;
00079 }
00080 
00081 bool JPEGCamera::reset() {
00082     char buf[4] = {0x56, 0x00, 0x26, 0x00};
00083     int ret = sendReceive(buf, sizeof buf, 4);
00084     if (ret == 4 && buf[0] == 0x76) {
00085         wait(4.0);
00086         state = READY;
00087     } else {
00088         state = ERROR;
00089     }
00090     return state == READY;
00091 }
00092 
00093 bool JPEGCamera::takePicture() {
00094     char buf[5] = {0x56, 0x00, 0x36, 0x01, 0x00};
00095     int ret = sendReceive(buf, sizeof buf, 5);
00096 
00097     return ret == 5 && buf[0] == 0x76;
00098 }
00099 
00100 bool JPEGCamera::stopPictures() {
00101     char buf[5] = {0x56, 0x00, 0x36, 0x01, 0x03};
00102     int ret = sendReceive(buf, sizeof buf, 5);
00103 
00104     return ret == 4 && buf[0] == 0x76;
00105 }
00106 
00107 int JPEGCamera::getImageSize() {
00108     char buf[9] = {0x56, 0x00, 0x34, 0x01, 0x00};
00109     int ret = sendReceive(buf, sizeof buf, 9);
00110 
00111     //The size is in the last 2 characters of the response.
00112     return (ret == 9 && buf[0] == 0x76) ? (buf[7] << 8 | buf[8]) : 0;
00113 }
00114 
00115 int JPEGCamera::readData(char *dataBuf, int size, int address) {
00116     char buf[16] = {0x56, 0x00, 0x32, 0x0C, 0x00, 0x0A, 0x00, 0x00,
00117                     address >> 8, address & 255, 0x00, 0x00, size >> 8, size & 255, 0x00, 0x0A
00118                    };
00119     int ret = sendReceive(buf, sizeof buf, 5);
00120 
00121     return (ret == 5 && buf[0] == 0x76) ? receive(dataBuf, size, DATA_TIMEOUT) : 0;
00122 }
00123 
00124 int JPEGCamera::sendReceive(char *buf, int sendSize, int receiveSize) {
00125     while (readable()) getc();
00126 
00127     for (int i = 0; i < sendSize; i++) putc(buf[i]);
00128 
00129     return receive(buf, receiveSize, RESPONSE_TIMEOUT);
00130 }
00131 
00132 int JPEGCamera::receive(char *buf, int size, int timeout) {
00133     timer.start();
00134     timer.reset();
00135 
00136     int i = 0;
00137     while (i < size && timer.read_ms() < timeout) {
00138         if (readable())
00139             buf[i++] = getc();
00140     }
00141 
00142     return i;
00143 }