HID Hi-O iCLASS Installation Guide - Manual (Page 38)

iCLASS OEM75 Integration Guide, 3141-907, Rev. B.0
Page 38 of 49 January 2014
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*pNumBytes = readByte();
//
// If there is no message data available, send a stop and return.
//
if (NULL_MSG == *pNumBytes)
{
sendI2CNak();
}
else
{
//
// If this point is reached, then the slave has message data to send us.
// Ack the last byte and continue.
//
sendI2CAck();
//
// Expecting only a maximum number of bytes.
//
if (*pNumBytes > I2C_MSG_BUFSIZE)
{
*pNumBytes = 0;
}
//
// Read the remaining bytes in the message.
//
cnt = 0;
while (cnt < *pNumBytes)
{
pData[cnt + 2] = readByte();
cnt++;
//
// Don't ACK the last byte. A stop is sent instead.
//
if (cnt < *pNumBytes)
{
sendI2CAck();
}
else
{
sendI2CNak();
}
}
}
//
// Send a stop and return.
//
sendI2CStop();
}
/**********************************************************************/
/************************** Private functions *************************/
/**********************************************************************/