munlaiji moljengo Profile Topics Started Replies Created Engagements Search replies: Forum Replies Created Viewing 1 post (of 1 total) Author Posts November 8, 2013 at 4:44 pm in reply to: GSM SIM 300 interfacing #10588 munlaiji moljengoParticipant i tried to send sms using sim300 and hyperterminal from my pc. i type AT then enter and i got ok meaning the modem is good next, AT+CMGF=1 OK AT+CMGS=234 phone number +cms error: 321 what have i done wrong please advice Author Posts Viewing 1 post (of 1 total)