Author Topic: Trigger signal  (Read 10770 times)

FilthyLucre

  • Member
  • ***
  • Posts: 2
Trigger signal
« on: July 19, 2012, 06:04:02 am »
Hello,

currently I´m working with a programm, that is a software to a thermal camera. Its an opensource, so I can change anything I want.

There is an Alarm function, that triggers beeping after reaching some temperature. I have to change this function, so I could get a 5V trigger signal from my pc to some device, that stops heating etc.

I`ve done some research and found out, that might be possible with serial or parallel port. How could I use those in C++? Are there any turorials?

Thx in advance!

Jan Axelson

  • Administrator
  • Frequent Contributor
  • *****
  • Posts: 3033
    • Lakeview Research
Re: Trigger signal
« Reply #1 on: July 19, 2012, 10:18:50 am »
On a serial port, use RTS or DTR.

In .NET's SerialPort class, see RTSEnable and DTREnable.

Or see:

http://www.cpdee.ufmg.br/~fvasc/Disciplinas/Interfaces/msdn_serial.pdf

You'll need a MAX232 or similar chip to convert to 5V logic.

Jan

FilthyLucre

  • Member
  • ***
  • Posts: 2
Re: Trigger signal
« Reply #2 on: July 23, 2012, 05:45:26 am »
On a serial port, use RTS or DTR.

In .NET's SerialPort class, see RTSEnable and DTREnable.

Or see:

http://www.cpdee.ufmg.br/~fvasc/Disciplinas/Interfaces/msdn_serial.pdf

You'll need a MAX232 or similar chip to convert to 5V logic.

Jan

Jan, thx a lot for your post. But I still have some questions about this conversion.

Once again, the problem is to convert the signal from pc's serial port to the simplest voltage of 5V or more.

For this matter, I need a max232 converter, to transform rs232 to TTL. Am I correct? How do I define the voltage that I need?

If I understand it correctly, I just have to send a signal to the serial port (rs 232), some message for example, and then this will be transmitted to max 232 and I will have my trigger 5 v voltage in the end?

Thx again!
« Last Edit: July 23, 2012, 06:06:57 am by FilthyLucre »

Jan Axelson

  • Administrator
  • Frequent Contributor
  • *****
  • Posts: 3033
    • Lakeview Research
Re: Trigger signal
« Reply #3 on: July 23, 2012, 06:19:26 pm »
Yes, the MAX232 does the conversion for you.

Jan