Hi,
I am going to interface a mobile phone to a microcontroller (pic). I am interfacing through a data cable. So, I want to interface MAX232 to the data cable. I only connected the Rx,Tx and GND. But, the mobile phone is not responding (Sony Ericsson T300). I herd that we should wire some additional MAX232 pins to the data cable(other than Rx,Tx and GND....They might be RTS,DTR... I dnt know). Please give me details of how to interface MAX232 to a mobile phone data cable.
Thank you very much.

 

You mean you put the data cable that already has a converter into to cell phone and then you want to convert the output of the data cable which is RS232 back to TTL level signals?

the original data cable is this one:
http://pinouts.ru/all/ericsson_cable_pinout.shtml
Is that what you have?

Apparently they don't really use the CTS RTS for anything. Can't u interface the cellphone directly? With an oscilloscope you could check first if you are sending the correct signal to the data cable.
Do you have all the data necessary to communicate with the cell phone? Baudrate, communication protocol etc.?

 

Did you swap RX and Tx? (Rx on the PIC goes to Tx on the phone)

 

Did you swap RX and Tx? (Rx on the PIC goes to Tx on the phone)

Of course, the most basic thing. I didn't count how many times THIS was wrongly wired in past projects...

 

Of course, the most basic thing. I didn't count how many times THIS was wrongly wired in past projects...

I'm about 50/50 on this. Less if you count the PicKit 6 pin connector, I have yet to wire that correctly the first time over a double dozen of breadboards.