We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
hi all
please help me . I want to connect 8051 uc to PC so that it can continuously transfer data received on it's port to the PC.
And How can i send data from uc to GSM network using mobile phone.
USB is most probably the preferable way to talk with a GSM phone/module, but unless you have a processor with USB, then a normal asynchronous serial interface is the most common.
DIY projects normally use a GSM phone, but that requires that you check if the serial connection on the phone is using RS232 signal levels, or if it is using TTL signals (3.3V, 5V or possibly something else). If using the standard cable for connecting the phone to a computer, then you know the other end of the cable will be using RS232 signal levels.
Commercial projects normally use GSM modules instead, i.e. basically a small circuit board with a high-density connector and a tiny coaxial connector (or solder hole) for fitting the cable of an antenna.
These modules normally interfaces using TTL levels. Many modules are making use of non-standard voltages (at least for the supply voltage) so it is imperative to read the datasheet.
In my experience, GSM modules do *not* use standard TTL levels!
Certainly not 5V, and usually not even 3.3V or 3V.
Levels like 2.7V or 1.8V are not uncommon.
"it is imperative to read the datasheet."
Asolutely!
You are correct. It was a bad expression for saying that the modules uses "naked logic levels", without any buffering.
It is quite common that logic level converters are needed between module and processor.