hi. I built a simple circuit from some parts that i extracted from a broken vcr. I wanted to use the ir to control my computer (using windows XP and Labview 7). After reading everything i could find on the ni support and modifying my computer I finally figured it out (if your trying to do something like this, read on). First, one of the pages in the knowledge base on the site talks about the different modes of a parallel port. Enter your bios and look around for the parallel port mode... set it to 1 (sp you can read and write). Also my type was ECP + EPP, I changed it only to ECP. Next, all the software updates that were recommended didn't make a difference, because Labview 7 contains the most recent ones. The thing that helped me out the most was this program called Lalim Parallel Port Control Basic (http://www.nonags.com/nonags/miscu.html). This program made me realize two key things that I was neglecting. I was numbering the pins on the port backwards. Also, there is not an individual value for each pin on the parallel port. The port is divided into 4 parts (status, etc) and writing to one of those pins with change the hex number that represents the part. Example, I use the status pins (9-13 top row). I write data to pin 13. This causes the status value (located at address 379 or base+1 to change from '127' to '111' because of the significance of the bit that I am changing. Basically, if you are interfacing something with the parallel port just read in the values from the parallel port (with in port.vi) and monitor its changes (for me 127 = 1 and 111 = 0). I hope this helps someone. If it did and you want to give me a hand, I was trying to power the circuit by the output of pin23 (because it is normally 1) but I need 10V to the circuit, not 5V. I tried many differnt ways to do this with capacitors and using other (multiple) pins, but nothing worked (I think it is because all the pins share the same ground). If you do know a way to do this (right now i just have it hooked up to a 9v) email me or just post a reply. thanks 😃
