LPCXpresso IDEのトピックRe: 11c24 UART Problem

11c24 UART Problem

lpcware — Wed, 15 Jun 2016 22:53:07 GMT

Content originally posted in LPCWare by nfs2k on Wed Mar 21 04:23:55 MST 2012
Hi

i got an lpc11c24 evaluation board.
i connected an USB to RS232/TTL/485 adapter to the RX and TX of the EV-Board.
from putty i was able to send eg. an 'a' and the lpc did an echo so i got back the 'a'.
now i connected the RX and TX to another converter which does 232 to 485 . on it there is a MAX232N and the MAX489CPD. Now if i send some data from the board into bus for example an 'a' another mcu gets somthing else but no 'a' .
anyone knows where the problem could be ?

thank you
nfs2k

Re: 11c24 UART Problem

lpcware — Wed, 15 Jun 2016 22:53:08 GMT

Content originally posted in LPCWare by Ex-Zero on Wed Mar 21 04:42:38 MST 2012

Quote: nfs2k
...now i connected the RX and TX to another converter which does 232 to 485 .

So you connected 3.3V TTL of LPC11C24 to RS232 input :confused:

Re: 11c24 UART Problem

lpcware — Wed, 15 Jun 2016 22:53:09 GMT

Content originally posted in LPCWare by nfs2k on Wed Mar 21 06:51:47 MST 2012
if i connect RX and TX to pins 9 & 10 of MAX232N which are for TTL use i can´t read nor write ... if i connect to pin 7 & 8 i can communicate but there are wrong characters... or fo i have the problem with the Voltage differences ?