// get a UART packet and update framebuffer
// if clear panel command is received -> clear frame buffer
// if start streaming command is received -> receive full image and update frame buffer
void getPixelsFromUART(void)
{
if(XMC_USIC_CH_RXFIFO_IsEmpty(XMC_UART0_CH0) == false && XMC_USIC_CH_RXFIFO_GetLevel(XMC_UART0_CH0) >= 5)
{
pixel[0] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0); // x
pixel[1] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0); // y
pixel[2] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0); // R
pixel[3] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0); // G
pixel[4] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0); // B
if(!(pixel[0] == 253 && pixel[1] == 253)) // if condition is true -> drawing pixel is
{ // received, no streaming of complete image
pixel[5] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0); // CS is read only if no
// start/stop streaming command is received
// synchronization -> until the checksum is correct, to find the correct x, y, R, G, B
// values for the particular pixel
while(pixel[5] != (pixel[0] ^ pixel[1] ^ pixel[2] ^ pixel[3] ^ pixel[4]) && XMC_USIC_CH_RXFIFO_IsEmpty(XMC_UART0_CH0) == false)
{
pixel[0] = pixel[1]; // x = y
pixel[1] = pixel[2]; // y = R
pixel[2] = pixel[3]; // R = G
pixel[3] = pixel[4]; // G = B
pixel[4] = pixel[5]; // B = CS
pixel[5] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0);
}
// clear panel if "clear panel" command is received
if(pixel[0] == 254 && pixel[1] == 254)
initEmptyPanel();
// update single pixels in the framebuffer if no "start streaming" command was received
else if(pixel[5] == (pixel[0] ^ pixel[1] ^ pixel[2] ^ pixel[3] ^ pixel[4]))
framebuffer_update_1px(pixel[0], pixel[1], pixel[2], pixel[3], pixel[4]);
}
// start streaming (filling the framebuffer) if "start streaming" command is received
else if (pixel[0] == 253 && pixel[1] == 253)
{
OE_H; // disable LED panel while receiving data
while(pixel[0] != 252 && pixel[1] != 252) // store the received pixel RGB values
{ // in the pixelbuffer
if(XMC_USIC_CH_RXFIFO_GetLevel(XMC_UART0_CH0) >= 5)
{
pixel[0] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0);
pixel[1] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0);
if(pixel[0] < 32 && pixel[1] < 32)
{
pixelbuffer[pixel[0]][pixel[1]][0] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0); // R
pixelbuffer[pixel[0]][pixel[1]][1] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0); // G
pixelbuffer[pixel[0]][pixel[1]][2] = XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0); // B
}
}
}
// Clear FIFO Buffer after stop streaming command was received
while(XMC_USIC_CH_RXFIFO_IsEmpty(XMC_UART0_CH0) == false)
{
XMC_USIC_CH_RXFIFO_GetData(XMC_UART0_CH0);
}
// after the streaming has finished - update framebuffer out of the filled pixelbuffer
for(int x=0;x<MATRIX_WIDTH;x++) {
for(int y=0;y<MATRIX_HEIGHT;y++) {
framebuffer_update_1px(x, y, pixelbuffer[x][y][0], pixelbuffer[x][y][1], pixelbuffer[x][y][2]);
}
}
OE_L; // enable LED panel when data is received and framebuffer updated
}
}
}
/**
* \brief Function for reading an amount of bytes out of a register of an I2C device - with assistance of the XMC-Library
*
* \param [in] handle Constant pointer to USIC channel structure
* \param [in] devAddr Contains the device address (master address)
* \param [in] regAddr Contains the address of the desired register
* \param [in] length The number of bytes to be read
* \param [in] data Pointer to the variable for saving the read data
* \return Return type is int16_t
* \return Returned value is the amount of successfully read bytes
*
* \details Reads data (more bytes) from a register of an I2C device
* \details You can choose the start address and the amount of bytes to be read
*/
int16_t I2Cdev_readBytes(XMC_USIC_CH_t* handle,uint8_t devAddr, uint8_t regAddr, uint8_t length, uint8_t* data)
{
uint16_t time_out_cnt = 0u;
XMC_I2C_CH_MasterStart(handle, devAddr, XMC_I2C_CH_CMD_WRITE);
while ((XMC_I2C_CH_GetStatusFlag(handle) & XMC_I2C_CH_STATUS_FLAG_ACK_RECEIVED) == 0U)
{
time_out_cnt++;
if (time_out_cnt > 200u)
{
return -1;
}
}
XMC_I2C_CH_ClearStatusFlag(handle,XMC_I2C_CH_STATUS_FLAG_ACK_RECEIVED);
time_out_cnt = 0u;
XMC_I2C_CH_MasterTransmit(handle, regAddr);
while ((XMC_I2C_CH_GetStatusFlag(handle) & XMC_I2C_CH_STATUS_FLAG_ACK_RECEIVED) == 0U)
{
time_out_cnt++;
if (time_out_cnt > 200u)
{
return -1;
}
}
XMC_I2C_CH_ClearStatusFlag(handle,XMC_I2C_CH_STATUS_FLAG_ACK_RECEIVED);
//---------------------------------------------------------------------------------------------------------------------------------
time_out_cnt = 0u;
XMC_I2C_CH_MasterRepeatedStart(handle, devAddr,XMC_I2C_CH_CMD_READ);
while ((XMC_I2C_CH_GetStatusFlag(handle) & XMC_I2C_CH_STATUS_FLAG_ACK_RECEIVED) == 0U)
{
time_out_cnt++;
if (time_out_cnt > 200u)
{
return -1;
}
}
XMC_I2C_CH_ClearStatusFlag(handle,XMC_I2C_CH_STATUS_FLAG_ACK_RECEIVED);
int16_t fifo_bytes;
for(fifo_bytes = 0;fifo_bytes<length;fifo_bytes++)
{
if(fifo_bytes < (length-1))
XMC_I2C_CH_MasterReceiveAck(handle);
else
XMC_I2C_CH_MasterReceiveNack(handle);
time_out_cnt = 0u;
while ((XMC_I2C_CH_GetStatusFlag(handle) & (XMC_I2C_CH_STATUS_FLAG_RECEIVE_INDICATION | XMC_I2C_CH_STATUS_FLAG_ALTERNATIVE_RECEIVE_INDICATION)) == 0U)
{
time_out_cnt++;
if (time_out_cnt > 200u)
{
return -1;
}
}
XMC_I2C_CH_ClearStatusFlag(handle,XMC_I2C_CH_STATUS_FLAG_RECEIVE_INDICATION | XMC_I2C_CH_STATUS_FLAG_ALTERNATIVE_RECEIVE_INDICATION);
}
XMC_I2C_CH_MasterStop(handle);
fifo_bytes=0;
while(!XMC_USIC_CH_RXFIFO_IsEmpty(handle))
{
data[fifo_bytes] = XMC_I2C_CH_GetReceivedData(handle);
fifo_bytes++;
}
XMC_I2C_CH_ClearStatusFlag(handle,XMC_I2C_CH_STATUS_FLAG_RECEIVE_INDICATION | XMC_I2C_CH_STATUS_FLAG_ALTERNATIVE_RECEIVE_INDICATION);
return fifo_bytes;
}