I'm stunned.
I'm using a gsm modem with microcontroller and communicate with the modem serially through the uart of the 8052.
when i issue the commands from the ucontroller i always get error message from the modem(invalid text mode) while if i issue the commands from hyper terminal i get the modem working correctly.
I can't figure what the problem is since i get the command and error messages echoed to the lcd then the serial port is working correctly, but the modem doesnt work properly.
I thought it might be something to do with the speed so i added a delay of 5 seconds between each letter sent to the modem and i got same response.
I removed my 8052 and connected the pcb to the pcs serial port thro' max232 chip. when i type the commands in hyper terminal, the modem responds correctly, I'm completly surprised and cant figure out whats wrong.
Any help plz?