void readPacket()
{
/*
* This is one way to read packets from the BluetoothPipe; using read(),
* and copying them into our own buffer. A faster but slightly more complex
* method would use peek() to access the next packet, and pop() to remove it.
*
* We only attempt to read n packets to avoid the edge case in which packets
* are arriving often enough to keep us in this loop indefinitely. Not likely
* a concern for real applications, but keeps things flowing smoothly for
* this example.
*/
UsbPacket packet;
unsigned n = usbPipe.receiveQueue.capacity();
while (n && usbPipe.read(packet)) {
n--;
/*
* We received a packet over USB!
* Dump out its contents in hexadecimal, to the log and the display.
*/
LOG("Received: %d bytes, type=%02x, data=%19h\n",
packet.size(), packet.type(), packet.bytes());
String<17> str;
str << "len=" << Hex(packet.size(), 2) << " type=" << Hex(packet.type(), 2);
vid.bg0rom.text(vec(1,10), str);
packetHexDumpLine(packet, str, 0);
vid.bg0rom.text(vec(0,12), str);
packetHexDumpLine(packet, str, 8);
vid.bg0rom.text(vec(0,13), str);
packetHexDumpLine(packet, str, 16);
vid.bg0rom.text(vec(0,14), str);
// Update our counters
updatePacketCounts(0, 1);
}
}
void packetHexDumpLine(const UsbPacket &packet, String<17> &str, unsigned index)
{
str.clear();
// Write up to 8 characters
for (unsigned i = 0; i < 8; ++i, ++index) {
if (index < packet.size()) {
str << Hex(packet.bytes()[index], 2);
} else {
str << " ";
}
}
}
