like the subject says…been searching for 2 hours and found nothing on this other then people have done it.
I know you can just jumper each SK pins and use on-board test pots as well as hook up external sensor with it’s own power… but how do you use the K8055’s 5V power and hook up a external pot?
Tried everything and the sliders on the demo just bounce with some random number in certain position. I can not get them still or to go 0-255 from an external pot. I am wondering if it is my board.
From my understanding, you connect the wiper (usually the middel) end of the pot to the A1 or A2. The other outside ends go to the boards 5V and other to ground depending on which way you want to turn the pot for increased/decrease direction.
I have tried this and nothing. I assume that for ground you can use any ground screw terminal of board but also tried SK ground (both) as well as connected them to screw terminal ground (in case they were not common) still nothing.
Some illustration I’ve seen (including the manual) show a sensor connection as being 2 wires one to A1 or A2 and one to 5V of either SK (I assume it does not matter which ones used in this case only for the test pots). In this illustration It also describes connection of ground of SK to ground screw terminal that is near the A1/A2s (but shouldn’t all ground be common on the board?
The above did not work, but then again it is for a sensor with 2 connection (what about 3 - as most sliders/dials and pots have 3)?
I did not install 1 test pot to the board cause not needing 2 as I only intend to use external pots anyway.
Do those little test pots complete some circuit required? Meaning do they need to be there (and/or in some position) to get A1 or A2 to work with external pot.
Sorry about the long post…but wanted to relay everything I have tried.
[quote]From my understanding, you connect the wiper (usually the middel) end of the pot to the A1 or A2. The other outside ends go to the boards 5V and other to ground depending on which way you want to turn the pot for increased/decrease direction.[/quote]Your connection looks OK.
Just adjust trimmer potentiometers ATT1 and ATT2 to max. position clockwise to get good reading.
took the test pots off cause not wanting to use them and put a screw terminal in place (glued overtop the poistion where pots were…I wanted fast access to 5V. Only other way is to make some crimp connector cable for the pins. I think those should have been in the kit if that is how they want us to connect
So my question is, do the test pots need to be in place and all the way clockwise for it to work?
If this is true, I will have to have the pot/s dangling by wire from connection underneith set them on full then do the jumper connection and solder to 5V from underneith instead.
Right now one jumper pin connector (header) is removed cause I am soldering to its 5V from above. I wish the board had a 5V screw terminal in its design (would make things sooo much easier) for AD input.
Just want to confirm before doing a solder work around to get it all back now. I was under the impression that those pots were extra and not needed if you intend to go external exclusively. My intent is to have a screw terminal for all 3 connection and have it easy to connect 1 or 2 pots
please confirm.
If not it must be the board itself. I tested the board with the pots before when I did have on and it did nothing but now see you have to jumper the SK for the one you want to use.
No need to have the test pots. You can replace those with your own pots.
[quote] I wish the board had a 5V screw terminal in its design (would make things sooo much easier) for AD input.[/quote] The idea is to feed external voltage to the analog inputs. See the diagram on page 19 of the manual how to connect the inputs to external voltage source.
So I can’t get this to work with the board’s 5V? It appears I have everything hooked up correctly to do this, but your last statement makes me think we can either control with on-board test bots or use a external pot with external 5V (which seems silly when you have access to 5V from the board.) That is the part that I am getting hung up on. I thought I saw where other have done it, but maybe they used external 5V and did not mention that?
I must be missing something?
so is there any work around to use the 5V from board?
If you are very careful and you know exactly what you are doing, then you may use the internal +5V of the board.
Anyhow I recommend to use an external power supply e.g. battery. This is more safe solution. Doing this you can’t so easily damage your PC by short circuiting or overloading the internal +5V USB supply of the board. (Anyhow there is a short circuit/overload protection circuit in the PC trying to avoid any damage…)
I am just trying to get it to work like other boards I have used (Phidgets)…you just connect the pot the standard way mentioned and your all set…using onboard 5V.
Well…it sounds like I have it the way it should and it still does not work. I am wondering if it is my board or maybe the IC1 that the analog lines run through that is maybe bad?
I could still try to jumper a test pot and double check, but pretty sure I did that from the start. but not 100% sure where I had the jumpers.
I assume when you saw “short circut”, you mean a bad solder job where the connection where done wrong. All connections have been tested with a meter and it is hooked up correctly, I am just wondering if my board has an issue, cause this should just work I am thinking. I suppose the over load part would come when you are using both pots, all outputs and maybe the pwms at the same time? would you say there is a general rule to not use other ports when using pots and internal 5V? Kind of wondering cause aren’t the test pots using internal 5V when they are utilized?
[quote]I could still try to jumper a test pot and double check, but pretty sure I did that from the start. but not 100% sure where I had the jumpers.[/quote] Indeed, it is good idea to replace the internal test pots and jumpers to check the operation of the board.
[quote]I suppose the over load part would come when you are using both pots, all outputs and maybe the pwms at the same time? would you say there is a general rule to not use other ports when using pots and internal 5V?[/quote] Do not connect the internal +5V to your circuit.
There is no worry about overloading the USB +5V supply if you are using the internal test pots only. You may load all the digital outputs and PWM as specified:
digital open collector output switches (max. 50V/100mA)
PWM 0 to 100% open collector outputs max 100mA / 40V
I am confused about your statement that onboard 5V can be used with external pot. Because you mentioned it and then stated
and then stated yesterday
wondering the correct connection for the 5V to an external pot and what the issues may be as it seems doing this will cause a probelm. I understand the warnings but what is the correct wiring for this? as you have stated
it will be difficult to use an external battery because I want to enclose all in a case and all taped out on extra space since the board is so large itself. do not want to use a 5V AC wall adapter as well just for the pots.