Hi, i'm a newbies, sorry if my english is not so good as your, but i'm french. lol
i would like to interface a pic with a GSM. I have a old Ericson T20e, nokia 3310 and nokia 5110, my first question is : does all of this GSM support AT command?
2d question: is there someone have a schematic to build a datacable for this GSM?
3d question: for the nokia GSM does the level is 2.7V or 5V? and for the ericson? 5V?
4d question: i try to communicate with those GSM with hyperterminal windows software, with a selfmade datacable but it doesn't work . For the ericson i use it with 5V for RX-TX, when i send the AT command like AT? i only have the echo but no response.
For the nokia, i use them with 3V for RX-TX, i dont use the Mbus, simply in F-BUS mode, here when i send an AT command i have no response, either none echo.
I have try with different transmission speed without good result..
Can you help me please?