static CameraPacket getPacket(void)
{
T2CON = 0x0020; // disabled, prescaled, internal oscillator
TMR2 = 0; // clear the timer
PR2 = CLOCKS_PER_SEC/64/10 - 1; // interrupt at 1kHz (1ms)
_T2IE = ON; // enable Timer2 to interrupt
_T2IF = OFF; // clear the interrupt flag
_T2IP = 4; // set priority to real-time
T2CONbits.TON = 1;
CameraPacket inPacket = newCameraPacket();
while(cameraComPort.size() < 8) if(!T2CONbits.TON) break;
cameraComPort.receive(inPacket.raw,8);
return inPacket;
}
static CameraError getPicture(void)
{
toCam = newCameraPacket(),
fromCam = newCameraPacket();
toCam.cmdToken = SYNC;
int syncTries = 0;
//if(!imageFile.open)
if(!imageFile)
return NO_FILE;
/* try and get sync with camera */
while(!(fromCam.cmdToken == ACK && fromCam.parameter1 == SYNC)) // until ACK received
{
if(syncTries == 3)
cameraComPort.baudrate(115200);
cameraComPort.flush();
sendPacket(toCam); // send SYNC command
pause(25);
fromCam = getPacket(); // get reply
if(syncTries < 7)
++syncTries;
else
return NO_HANDSHAKE;
}
/* acknowledge camera's sync request */
toCam = newCameraPacket(); // initialize packet
toCam.cmdToken = ACK; // acknowledge
toCam.parameter1 = SYNC; // the sync
syncTries = 0;
while(!(fromCam.cmdToken == SYNC)) // wait for camera SYNC request
{
fromCam = getPacket();
if(syncTries < 7)
++syncTries;
else
return NO_SYNC;
}
sendPacket(toCam);
/* configure camera */
toCam = newCameraPacket(); // initialize packet
toCam.cmdToken = INITIAL; // initial configuration
toCam.parameter1 = 0x04; // 115,200 baud rate
toCam.parameter2 = 0x87; // compress color
toCam.parameter3 = 0x01; // 80x60 preview resolution
toCam.parameter4 = 0x07; // 640x480 compression resolution
sendPacket(toCam);
/* if camera acknowledges changes, change the UART baud rate */
fromCam = getPacket();
if(!(fromCam.cmdToken == ACK && fromCam.parameter1 == INITIAL))
return NO_INITIAL;// if reconfiguration was not successful
cameraComPort.baudrate(115200); // change UART baud rate
/* specify image quality */
toCam = newCameraPacket(); // initialize packet
toCam.cmdToken = QUALITY; // configure picture quality
toCam.parameter1 = 0x00; // to be the best
sendPacket(toCam);
/* if camera acknowledges change, then get an image */
fromCam = getPacket();
if(!(fromCam.cmdToken == ACK && fromCam.parameter1 == QUALITY))
return NO_QUALITY;// if reconfiguration was not successful
/* get an image */
toCam = newCameraPacket(); // initialize packet
toCam.cmdToken = GET_PIC; // configure picture quality
toCam.parameter1 = 0x05; // get full size image
sendPacket(toCam);
/* if camera acknowledges request, then retrieve image data */
fromCam = getPacket();
if(!(fromCam.cmdToken == ACK && fromCam.parameter1 == GET_PIC))
return NO_GET_PIC; // if request was not successful
/* get image size */
fromCam = getPacket();
if(!(fromCam.cmdToken == DATA))
return NO_DATA; // if request was not successful
/* read data size */
picsize = bytesToGet = fromCam.parameter2 + fromCam.parameter3 * 0x100LL + fromCam.parameter4 * 0x10000LL;
int cnt = 0;
/* store the image */
while(bytesToGet > 0) // until all bytes retrieved
{
tempSize = cameraComPort.receive(tempBuffer, RX_BUFFER_SIZE); // receive the bytes
//imageFile.write(tempBuffer,tempSize); // store the bytes
FSfwrite(tempBuffer, sizeof(char), tempSize, imageFile);
bytesToGet -= tempSize; // update bytes remaining
// watch dog counter - bytes are sometimes lost...so loop will hang
cnt = tempSize ? 0: cnt + 1;
if(cnt > 200)
break;
}
/* acknowledge that data was received */
/* NOT NEEDED */
//toCam = newCameraPacket(); // initialize packet
//toCam.cmdToken = ACK; // notify the camera of successful
//toCam.parameter1 = DATA; // data retrieval
//sendPacket(toCam);
pause(30);
if(bytesToGet)
return LOST_DATA; // not all camera data was gathered
else
return NO_ERROR; // successful
}