SIM300 EVB AT commands problem

[p133_3322]

SIM300 problem

Hi All:
I have a sim300 EVB, I connected it with my design board with LPC2388 microcontroller by RS232, I send AT command to the EVB and Its respond data was wrong ,for example I send "AT+CGATT\r" to Sim300 but the data I recieved was "AT% C", but I connected the EVB to PC it's no problem, I connected my board to PC it's no problem too, so What's going on ? I just connect TX ,RX ,GND from my board to EVB ,It's correct? somebody can help me ! thanks

 

[fiolin]

SIM300 problem

Did you used DB9 EVB connector to send AT command to the microcontroller?

 

[Praful]

There is no need of RS232 between sim300 and uC see datasheet...