Electronic Control

[yrwyddfa]

Hello chaps,

I'd like to control some electronics by using my PC. Does anyone know of any voltage controlling devices which have a programmable interface and attach to a PC?

I've found a Velleman Experimentation USB Board, but it's £30; and I wondered if I could do it more cheaply.

Any help or advice would be most appreciated.

Cheers,

Yr

[namrekka]

Well you can connect some opto couplers direct to a comm-port.

[eranga262154]

Well you can connect some opto couplers direct to a comm-port.

Correct

I think to control voltages the best way to used com port. Check some documents on Computer Interfacing. You will find much work on com ports. And also it is easy to handle.

comm-port.

I think you mean com port.Stand for Component Object Model. Not comm-port. Right

[-TPM-]

...
I think you mean com port.Stand for Component Object Model. Not comm-port. Right

Actually com in com port is short for communications. Component Object Model would be a COM assembly

I've used the parallel port before, which I find easier for electronics as you have 12 I/O channels instead of 1 with serial (COM port and USB). http://www.logix4u.net/

[eranga262154]

I've used the parallel port before, which I find easier for electronics as you have 12 I/O channels instead of 1 with serial (COM port and USB).

Correct

But I think its depend on your usages, isn't it. In some cases it is easy to used parallel port rather than com port.

[namrekka]

I've used the parallel port before, which I find easier for electronics as you have 12 I/O channels instead of 1 with serial (COM port and USB)

However more then 1 I/O is possible. This shows 4 inputs and 2 outputs:
http://www.vbforums.com/showthread.php?t=394943
For this you don't need external tools, only the "MSComm object". The advantage of using the serial port is that you can connect directly opto couplers ,relays and switches to this port. No transistors, ic's are needed. Also the port is protected for short circuits and ESD. The parallel port is more sensitive for this and needs extra electronics. The advantage is more I/O.

[-TPM-]

However more then 1 I/O is possible. This shows 4 inputs and 2 outputs:
http://www.vbforums.com/showthread.php?t=394943
For this you don't need external tools, only the "MSComm object". The advantage of using the serial port is that you can connect directly opto couplers ,relays and switches to this port. No transistors, ic's are needed. Also the port is protected for short circuits and ESD. The parallel port is more sensitive for this and needs extra electronics. The advantage is more I/O.

That definatly isn't standard though. The parallel port uses a lower voltage (+5V vs +12V) but that doesn't mean you can't connect Relays and switches directly to it.

[namrekka]

That definatly isn't standard though. The parallel port uses a lower voltage (+5V vs +12V) but that doesn't mean you can't connect Relays and switches directly to it.

Oh yes you can! You have 12V with 10mA. If you use a sensitive relay (they are polarized) you can connect it directly. Even a LED with a diode in series and no resister. A switch can be connected by using a output (for power) and a input.

[RobDog888]

To get any increase of voltage from a parallel or COM port you need to design an electronic driver circuit. NEVER ever directly connect your circuit or components to your motherboard ports as if you have a blown circuit or component you can seriously damage your entire mobo. By having a driver circuit you can proect your mobo and increase the voltage.