hai all,gsm modem sim300+pic without max232...(iam using 3.7 volt cellphone battery for pic and modem.) can i communicate properley with modem and viceversa?.i do not interested to use max 232,advice me pls.:!:
As I can see from the datasheet rainbow.com.ua/upload/files/modemi/SIM300_HD_V1.06.pdf -
You can connect the Sim300 directly to the microcontroller without the Max232.
Check page 16 in the datasheet, you will find that the serial interface 1 has "TTL" voltage levels. So, you don't need to use a MAX232.
i compleated this without using max232.....16f676-(tx)->simcom sim300 rx in,sim300 tx out to 676 PIN RA_2.(i used #int ext to pole the signal+timedgetc() to filter at _ reply from sim300)....but some char are missing...anyway i can send sms nicely..)