Since I'm a noob when it comes to robotics, you're gonna have to go easy on me with all the terms. I just got VB to control the parallel port and make some LED's flash in sequence, etc. However, when I tried to make a step motor run (I have 2 types with different voltages), the motor didn't move and it just vibrated! Obviously the voltage on the parallel port (4.5V) isn't enough to power a 12v step motor. Thus, i was wondering on how I would get the parallel port to maximize its voltage. Also, what type of devices can I use to increase the voltage externally without screwing up my pc!
In the past I've built an opto-electronic isolator circuit that used the parallel port +5V as a switching control for a load-side application such as your stepping motor. In this case, you could implement whatever size power supply you wanted and the computer would be relatively safe (unless the isolator shorted). There are numerous sources of information on the internet if you search for opto- or optical electronics. Of course, you will need a basic knowledge of electronics and some equipment to build the circuit, but its pretty straight forward.
Can u please post the code and diagrams on how u got vb to make the LED's flash,I had no Idea this could be done.Just when I was getting bored with VB,It's amazing
LOL...it's really interesting. Not very complex, but it's limited to the equipment and amount of money you're willing to spend on external electronics (step motors, LED's, controllers, circuits, etc). All the code and stuff is included in the zip file, witht he IO.DLL that I use to access the parallel port. It might not work on your computer because of your port address. All I do is turn on and off the first 2 pins of the parallel port to make LED's flash. If u want more help on the subject..i'll write up a small tutorial to get you started!
Originally posted by INF3RN0666 This isn't exactly VB but it's VB related.
Since I'm a noob when it comes to robotics, you're gonna have to go easy on me with all the terms. I just got VB to control the parallel port and make some LED's flash in sequence, etc. However, when I tried to make a step motor run (I have 2 types with different voltages), the motor didn't move and it just vibrated! Obviously the voltage on the parallel port (4.5V) isn't enough to power a 12v step motor. Thus, i was wondering on how I would get the parallel port to maximize its voltage. Also, what type of devices can I use to increase the voltage externally without screwing up my pc!
First be careful trying to run circuits / Motor having required more power may damage your port. Secondly if you want to operate/control 12V SM with TTL output (5V) you must use amplifier circuit for that you produce 12V from TTL output.
I must advise you increase you electronics knowledge for making customs robotics output.
Good Luck
I will realy appreciate that tutorial - I need to know the pin configuration and how the LED was interfaced to the paralell port!!!
I think the output voltage of the paralell should be +5v but the led needs 1.6V. I could use a resistor to drop the voltage but then I could also put a current drain on the port. Do you have a diagram of how to do this???
LOL...thanx for the advice. Espicially that I'm using a new computer that I got a month ago.
The thing is, I just started robotics and I have learnt quite a bit through experimentation. There's no better way to learn other than trial and error. you learn from mistakes (Most of the time) but only if they are truely your own mistakes. Yeah, I can go get a book on robotics and go through it applying the examples, but I guarantee you that I won't learn anything until I make my own project. Am I right, or do you disagree?
AFish --> I will make that tutorial for you today after school (Past 3:30 EST). I will include diagrams, pin configurations, connections, and other stuff like that. I will also write fully commented code.
Connect the ground of your external circuit to the ground of the PC power supply. Use an opto-isolator to electrically isolate the PC paralell port from your circuit so that you do not blow up anything on your paralell port!!!
Sorry it's a day late but for anyone that's interested, here's a tutorial based on a collection of data to get anyone started on the Robotics field. A basic knowledge of VB is needed and how a computer works in order to understand this tutorial.
Originally posted by INF3RN0666 LOL...thanx for the advice. Espicially that I'm using a new computer that I got a month ago.
The thing is, I just started robotics and I have learnt quite a bit through experimentation. There's no better way to learn other than trial and error. you learn from mistakes (Most of the time) but only if they are truely your own mistakes. Yeah, I can go get a book on robotics and go through it applying the examples, but I guarantee you that I won't learn anything until I make my own project. Am I right, or do you disagree?
I Agree man learn from mistakes. And many people won’t understand/clear thing without do it them self, I also. I want to say you that if you don’t take care about your parallel port it may damage and not function properly. In that case you can’t judge is it some fault in you circuit or in parallel port function.
Normally we sue driver IC for operate motor spatially when we use digital signal for controlling motor because digital signal have low power. You can use ULN2003 / MC1413 or any other you want. You can find some circuit/tutorial at
when i first started playing with this stuff I didnt really know to control the loads from the par port either...one of the things I ended up doing for safety was to use an old junk computer someone was throwing out and putting an old OS on it like OS2 , win 3.1, or win95 that let you easily have direct access to the parallel ports, then i bought a couple cheap eisa parallel ports cards off ebay (like 2-3bucks apiece) , figure that way if you blow anything...oghh well
also with the old systems you can pick up a copy of borland turbo C and just directly interface with the par port with the standard C runtime functions...my normal sys is win2k so it was just easier
to control the loads safely you have to make sure you dont craw to much current from the parallel port , it cant handle it...thats why they recommend the optoisolator, only use the signals from the pc for logic switching not source current, the isolator also physically seperates the two sides of the circuit from stuff like voltage spikes from inductive loads like motors or solinoids...
to drive the loads, just use a driver chip like the uln2803 ....i was thinking about making up a tut on it sometime cause I couldnt find anythign that really put it all together for me in one place....
after playing with the par port some...another really cool thing to play with is microcontrollers, computer on a chip , run off a battery, tons of lines of output/input and other cool functionality built in....but that s a whole other post
I was just looking at some hardware for robotics. I failed to find a Stepper Motor Controller though. Typically, how much do they cost, and where can I get them for cheap?
Reply With Quote
Control LED's ???
