I am getting extra characters at the end of a string I am sending via UART to my PC. I am sending the string "North: 0x" and I get the following output (as seen in Hyperterminal):
N o r t h : 0 x %(without the spaces and % representing the extra characters)
4E 6F 72 74 68 3A 20 30 78 0F 00 00 00 0D 0A (hexadecimal representation)
with the extra characters being the 0x0F 0x00 0x00 0x00.
My code extract is as follows:
; print "North :"
ldi r31, HIGH(2*north_txt)
ldi r30, LOW(2*north_txt)
; UART SETUP
; baud rate passed via registers r17(H) and r16(L)
sts UBRR0H, r17
sts UBRR0L, r16
; enable Tx and RX
ldi r16, (1 << RXEN0 | 1 << TXEN0)
sts UCSR0B, r16
; frame format - 8bits, no parity, 1 stop bit
ldi r16, (1 << UCSZ01 | 1 << UCSZ00)
sts UCSR0C, r16
; data to be transmitted must be loaded into
; register r16
lds r17, UCSR0A
sbrs r17, UDRE0
sts UDR0, r16
lpm r16, Z+
; check for end of string
cpi r16, 0x00
; next character
north_txt: .db "North: 0x", 0x00
I am using AVR Studio 4 on a Windows XP SP3 to program the Atmega328P on an Arduino Duemilanove.
Has anybody had the same problem and how do I resolve it?