# Thread: X and Y axis

1. ## X and Y axis

Hi Guys,

Need a little help if possible.. I have a BU0386X card and I can not for the life of me get it to recognise the X and Y axis when connected to a potentiometer on a long wire. Connected to potentiometer on a short wire.. no problems.. recognises it straight away. I am trying to connect my yoke so the wire is around 2 meters long. Only thing i can think of is the longer wire is causing the problem.. Any ideas??

Thanks

Mark

2. ## Re: X and Y axis

What gauge and type of wire? If you are getting to much of a voltage drop on the long run that may be the problem. For analog inputs I try to keep my wire runs as short as is practical.

3. ## Re: X and Y axis

Doctor my arm hurts when I bend it like that.. Then don't bend it like that..

I'm thinking the amount of resistance in the length and code of the wire is being eaten up in the line itself. Since a potentiometer varies resistance then you have a situation where you want all (most) of it to be sent by the pot. I would move the BU0386X closer to the pot.

You could check the resistance of the line using a multimeter. There is also the amount of voltage being sent via USB to the BU0368X. I'm not sure how much that is but it has to travel down from the computer to the unit to the pot and back and then back to the computer. Not saying there isn't enough voltage for that but the longer the line the more it has to travel and that could weaken the ability to read the unit.

A pot varies resistance so the lower the value the harder it will be for the BU0386X to read it add to that the resistance in the line itself and the amount of voltage it has to start out with (USB) and you begin to see the situation. As soon as the power leaves the computer it begins to loose voltage as it travels.. You also have to think of the trip to the pot and back as a round trip. So 2 meters is actually 4 meters. So less traveling is best.

I would check the resistance of the line both long and short (to the pot) via multimeter and then double that number and subtract that from the lowest level of the pot in resistance and you may find your minimum length of wire of that code you can use before the read resistance is less then the minimum amount of the pots value.

I wonder if there is a calculator out there for the amount of loss for various codes of wire?? hum.

Found one hehe Voltage Drop Calculator

Hope that helps
Ron

I found that the amount of voltage available via USB is 5v DC (power) with 500ma (data channel)

4. ## Re: X and Y axis

Hi Ron And Tom,

I kind of guessed the problem was the wire but I needed someone smarter than me to confirm it. I even tried telephone wire but that didn't work either. so the plan is to do some testing with a multimeter and diffrent coded wire and as you say.. find the best and most practical length with the least amount of loss.

Mark

5. ## Re: X and Y axis

Originally Posted by Jasper
Hi Guys,

Need a little help if possible.. I have a BU0386X card and I can not for the life of me get it to recognise the X and Y axis when connected to a potentiometer on a long wire. Connected to potentiometer on a short wire.. no problems.. recognises it straight away. I am trying to connect my yoke so the wire is around 2 meters long. Only thing i can think of is the longer wire is causing the problem.. Any ideas??

Thanks

Mark
Hi,
Should be using Shieled wire and keep lead length to real minimum. Not sure what max length can be.
Les

6. ## Re: X and Y axis

Is there a really good reason to have the BU0386X so far away from the yoke pots? You should be able to run a USB extension to the BU0386X from your computer that would probably solve your problem. Remember it's not the computer I/O side (before the BU0386X) it's the reading (after the BU0386X) that's important. Now it can't be real long either but that signal is the data signal coming back to the computer. The voltage might be stored in the BU0386X so it can sent quite a way. Think of the unit as a joystick. I have an extension plugged into my logitech gamepad that lets me use it about 10 feet away (GP cord = 4' and extension = 6').

Just as a note. When you are done with your experiments it would be cool if you posted your results. I know Leo perhaps could use that info but a ton of people 'myself included' could also use the help.

Ron

7. ## Re: X and Y axis

Follow up on the x and y axis problems. OK.. Ron pretty much hit the nail on the head with the comment that the resistance drop was proberly my problem. Given that one of the pots is located just behind the yoke and that the wire has to travel up to this ( 810mm ) and then from the bottom of the yoke colume to the interface card (mounted under the TQ on the side of the pedestal) so in all around 1.8 meters. No amount of testing with a multimeter and diffrent types or wire was ever going to give me any other result than it does'nt work. BUT!! I did discover that the computer can be tricked lol. Buy hooking a spare pot on short wires to the card and then booting the computer up it will reconize the pot. Then disconnect the short wire pot and connect the long wired pot and it works ( did for me anyway ) This did not fix my problem but did allow me to test the yoke and buttons, and of course as soon as you turn the computer off or unplug the USB it losses the axis again. Now all I have to do is redesign my yoke to move the pot closer to the card and hopefully everything will work as it should.

Mark

8. ## Re: X and Y axis

Um.. Why not move the card closer to the pot? The USB cable coming from the card could be pretty long but the card (resistance to be detected) has to be pretty short. So it's the card picking up the pot not the computer detecting the card. So if the card is closer to the pot the card will pick it up and the computer can be a distance away and still pick it up.

I know that may create another problem in as much as you have your other controls trying to talk to the card and they are probably a distance away from the card if it's moved. So I would suggest more then one card. Use one card as your MIP/Yoke input and another as your rudder/lower control input and then map accordingly.

In any case you may want to try increasing the length of USB cable between the card and your computer if you have USB extensions available? and see if it can still pick it up. There is a limit to that too but it's about 15' or 5m max I've heard well within your distance calculations.

Cheers
Ron