uartcallback

function uartRead() {
	local readValue = "";
	// pause to let partner device finish writing command
	// at 9600 baud, it takes about 1.04ms to write a byte 
	// (8 bits plus start bit and stop bit = 10 bits)
	// so, it'll take about 4.16 ms to write a 4-byte word
	// we'll wait even longer for demonstration purposes here
	imp.sleep(0.005);
	// now empty the FIFO
	local b = uart.read();
	while (b != -1) {
		readValue += format("%c",b);
		b = uart.read();
	}
	server.log("Got: "+readValue);
}

// configure the UART to use the callback function above
uart <- hardware.uart12;
uart.configure(9600, 8, PARITY_NONE, 1, NO_CTSRTS, uartRead);

// send a command to kick things off
uart.write("AT\n");