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