Archived

This topic is now archived and is closed to further replies.

lasher

serial interface

Recommended Posts

ok, I have this project I am working on, and I could use a little help, if anyone is willing. Some background first. What I am doing is modeling a prison and its security system. There is actually a physical model for the prison. There are various circuits in the model that indicate if a security point has been breached. For example if the fence is touched then the circuit monitering the fence will send a signal. I want the signal to be sent through a serial interface to a computer, and this is where I am stuck. If the circuit sends a high bit to the serial port when the fence is breached.. how do I read from the serial port to determin this has happened? Can you send a single bit to the serial port.. if its high then you have a security breach, if its low everything is fine? Any tutorials on reading from the serial port would be great.

Share this post


Link to post
Share on other sites
Interesting project. You can interface with the serial port in a number of ways.

This is how I would do it, depending on your level of electronics and programming. I like using microcontrollers for projects like these where I have to interface a system to a computer. I''ve been using the Motorola 68HC11 for quite some time now and believe it''s a practical little unit. The controller itself has a number of digital and analog IO ports for external interfacing, in this case the circuit monitoring the fence. When this occurs, you can send information back to the computer (either in terms of bits of data or ascii characters) through the serial port and let the computer interpret the rest.

There are a number of microcontrollers on the market. During my undergrad thesis I used the MicroCore11 from Technological Arts in Canada (www.technologicalarts.com). Then again you can always build your own system.

If you need specifics on programming the 68HC11, I''d be more than happy to help out.

Share this post


Link to post
Share on other sites
The problem with serial ports is you''ll probably have to get a UART chip, a RS-232 transceiver, and a micro-controller to talk to your PC.

If I were you, I''d look into parallel ports. That might be easier to accomplish. Either way, it''ll take a bit of homework on your part.

Good luck!

Share this post


Link to post
Share on other sites
quote:
Original post by BeerNutts
The problem with serial ports is you''ll probably have to get a UART chip, a RS-232 transceiver, and a micro-controller to talk to your PC.



The RS-232 chip is a UART. You can get more upto date UARTs now... Whether they are compatible with your PC is another thing. I think that the parallel port maybe sufficient for what you want to do. Serial communication is usually used when alot of data is being transferred, not just one bit. The parallel port is also a hell of alot easier to use.

Oh btw - remember to isolate your external circuit from your PC port, don''t want to accidentally fry it now do you?



Death of one is a tragedy, death of a million is just a statistic.

Share this post


Link to post
Share on other sites