DTR to 5V.

[ice-egoz]

I did put a qn onthe forum previously. I don know whether the qn was too difficult or >?
Anyway, I wanna know how to set the DTR to 5V. I have read up but I don see how i can actually set it to 5V. Is it through cabling? I have no idea cos I wasnt taught cabling and im doing a proj totally not what I learned. I had hoped that I cud get some info here.
Thanks.

 

[checkmate]

What DTR? Are you referring to the Data Terminal Ready signal of the RS232 serial port?

 

[StupidDum]

... have no idea cos I wasnt taught cabling and im doing a proj totally not what I learned. I had hoped that I cud get some info here.
Thanks.

I have no idea what are you talking about.
To interface RS232 and microcontroller, all you need is a 232 voltage level converter IC, such as MAX232

 

[Nigel Goodwin]

I did put a qn onthe forum previously. I don know whether the qn was too difficult or >?
Anyway, I wanna know how to set the DTR to 5V. I have read up but I don see how i can actually set it to 5V. Is it through cabling? I have no idea cos I wasnt taught cabling and im doing a proj totally not what I learned. I had hoped that I cud get some info here.
Thanks.

You can't 'set it' to 5V, only -12V or +12V, it's an RS232 signal. You can generate a low power 5V rail from it by setting it to +12V and using a 5V regulator to drop it to 5V - a simple resistor and zener would probably be enough.

 

[ice-egoz]

:?
Hi. Ya. I have my program up and i just need to send the program to the BS2p and it is interfaced to the GSM modem.
The BS2p and GSM modem is interfaced thru' the serial port.
The DTR of the GSM modem is to be set to 5V.
I have checked up on MAX 232 as well as regulators. So actually i need to use either of that to make it working? WHich means that I need to do the cabling in the breadboard is it?

 

[StupidDum]

Usually the modem itself already has a 232 chip inside.

 

[Nigel Goodwin]

:?
Hi. Ya. I have my program up and i just need to send the program to the BS2p and it is interfaced to the GSM modem.
The BS2p and GSM modem is interfaced thru' the serial port.
The DTR of the GSM modem is to be set to 5V.
I have checked up on MAX 232 as well as regulators. So actually i need to use either of that to make it working? WHich means that I need to do the cabling in the breadboard is it?

It's possible that the GSM modem doesn't use proper RS232, it could be using just 5V logic signals - it depends completely on what it's designed to connect to. Presumably it's specification will be provided in it's documentation, you need to check there.

Assuming it is just 5V logic, you can connect PIC (or BS2) pins directly to it - no MAX232 required, but you will need to check the polarity of the logic - usually 5V logic is inverted with respect to RS232, because a MAX232 inverts the signal.

 

[ice-egoz]

15-pin to 9pin

Hi. The thing is that the GSM modem has a 15-pin female port. The Rx pin should be linked to the SOUT of the BS2p. So, the DTR should be tied to +5V. I dont think the BS2p has 232 chip in it.

 

[checkmate]

I don't quite get what you are implying. So, is the serial communication between the BS2 and GSM Modem (which is in turn designed to connect to a PC and not a uC)? If it is so, you may probably need a MAX232 to be connected on the BS2 side of the circuit.
As for the serial pinout conversions, you may refer to **broken link removed**