rs232transmit

das tut so weit, allerdings zeichen nicht optimal, wissen:

USBS: USART STOP BIT SELECT
UCSZ2..0: USART CHARACTER SIZE (ich weiss nicht, 2 ist in C und 1..0 in B)... aber nicht jetzt entscheidend
UPM1:0 USART PARITY MODE, B oder C

hier der quelltext

;; (c) david vajda
;; 07/22/2026
;; rs232/transmit

.include "m8def.inc"

ldi r16, HIGH (RAMEND)
out SPH, r16
ldi r16, LOW (RAMEND)
out SPL, r16

ldi r16, HIGH (25)
out UBRRH, r16
ldi r16, LOW (25)
out UBRRL, r16

ldi r16, (1 << URSEL)
out UCSRC, r16
ldi r16, (1 << TXEN)
out UCSRB, r16

main001:
ldi ZH, HIGH (2*msg)
ldi ZL, LOW (2*msg)
rs232transmitmsg001:
lpm r16, Z+
cpi r16, 0x00
breq main001
rcall rs232transmitch001
rjmp rs232transmitmsg001

msg: .db "david@https://www.vajda-breadboard.de", 10, 13, 0

rs232transmitch001:
sbis UCSRA, UDRE
rjmp rs232transmitch001
out UDR, r16
ret