i am working on a project that requires me to send an SMS to 8051 micro controller,i want use USB modem from huawei model E160E,HSDPA USB stick,is there any way i can achieve this with out using the computer for interfacing
There must be literally thousands of cicuit diagrams on the web showing RS232 connection to an 8051 in general, and to a modem in particular.
It has been discussed very many times on this very forum - use the 'Search' box.
Study the documentation for your chosen modem to check for any specific requirements.
if you need help me with circuity diagram, you are already lost.
sinmce you ask this I see a need to tell you "a wire/trace is not a wire" it is a series of inductors with capacitors liberally spread along it.
if you do a willy-nilly layout (or even worse a "flying lead circuit") it will not work.
Erik
It would certainly be possible to fling together a GPS module, low-end 8051, and GSM Modem using "flying leads" and have it "work" (sic) - it can all be done with low-speed RS232 (or logic-level equivalent)...
eg, look at the photos here: msmvps.com/.../SerialPort-_2800_RS_2D00_232-Serial-COM-Port_2900_-in-C_2300_-.NET.aspx