when ever you are trying to | Microcontroller › 8051 › Interfacing GSM modem with 80s52 › when ever you are trying to April 13, 2013 at 10:33 am #9483 RUBEN KURIAKOSEParticipant when ever you are trying to interface a TTL device with a CMOS use aMAX 232 between them since there requires a voltage change over.
