Hello everyone,
This is my first time posting here. I have an issue I hope i can get some help with. I have noise with my 737 v3 throttle quadrant pots. My throttle #1, speed brake and occasionally my flaps potentiometer are all jittery. I have tried the capacitor fix mentioned on this site but that didn't work (1000uF, 25V). When I installed the capacitors the jitters were reduced but this also slowed the response of the pots to a crawl. I am not sure if this size is correct or I may have bad pots since all these pots are the same (RV24YN 20S HQ POT 10K Ohm).
I am using this throttle quadrant with XPlane and the Zibo Mod aircraft. I also find that my speed brake axis is very hard to be recognized/detected when calibrating, the change in value is very small when ever I move it in its full travel. Any help would be greatly appreciated.
Kevin,
The noise may come from the USB connection - PCs generate a lot of electrical noise. You can build a stable, clean 5V supply with 3 components, and run it from 9 to 12volts.
Noise increases when wires are parallel and close. The longer and closer, more noise is picked up
Ideally analog lines would be short and cross at right angles to other lines.
The Leo boards won't make the noise go away. But they may take an average reading, which could even out some of the noise.
Best to focus on wiring, keeping analog inputs and their power/ground separate from the other wiring.
On the Arduinos you can disable USB power and run them from say 12V, which would eliminate USB noise.
If you have access to an oscilloscope the noise can be tracked down in 10 minutes.
Paul
Almost a drop
in replacement, needed the hole being drilled 1mm more or a little filing.. but works great.. have 4 extras so going to make another for a colleague
For background info check out the https://realsimcontrol.com/sys_pwr.html website - they have excellent advice on ground (GND) distribution, along with do's and dont's. In the analog world you always have to be careful to control noise, especially noise picked up through power lines or power supplies. BTW: Your 1000uf capacitor was way far too high for filtering flightsim signals, but I guess you realised that.
Hey guys, I'm stuck at work on my 7 days on crew with just my phone and extremely poor Internet. I will answer when I get a chance, just wanted you all to know I'm not ignoring anyone and this has been an awesome read! Keep safe Karl
UPDATE
I finally figured out what was causing the suspected noisy pots. The terminal adapter I am using was the source of the issue. In an attempt to securely hold the wires in place I was inadvertently braking the solder connection on the back side when I apply force to tighten the screws. I discovered this yesterday while tightening on of the screws and heard a pop. I added some solder to the broken connection and this resolved it. To prove my discovery I moved the ground of the suspected noisy pot back to the bundle and it works fine. I do apologize for the false alarm on noisy pots.
Wiper? I Tried Windows game controller as well and it doesn’t calibrate there either to be honest it’s all over the place I followed the wiring that Karl set up in the build. I wired the pots the same way as I did with the speed brake and the flaps and they work okay. I’m wondering if I should use certain pins on the Arduino for certain actions on the throttles
How did you connect the ground? If you need some help troubleshooting I am willing to help. The design I pretty much stable except for the jitters.
Hello All,
So I seem the have resolved the issue. The only problem is, I cannot definitively say what resolved the issue. I suspect this may have been caused by a faulty grounding connection. In an attempt to increase the maintainability of the throttle I added a terminal board and two wire nuts (as opposed to soldering the bundle) for the grounding and Vcc (See photo). To troubleshoot, I have replaced the terminal board and adjusted the axis of the throttle 1 pot to turn between approx. 66 and 250 degrees. After reassembly I noticed throttle 1 was dead completely, I swapped the inputs of throttle 1 and 2 on the board to rule out a faulty board (throttle worked on both inputs). I then remove the throttle 1 pot ground from the bundle and attached it to its own ground (no other wires connected to this ground) and that seemed to do the trick for now. I will do a couple flights and see how this holds up. Even the speed brake works well now (on the ground, have not tested in flight as yet). I think I need to study how grounding could possibly affect signals. Thanks for the help and I will keep you posted.
Karl,
it has not always been like this with the throttle. I have always had jitters on the speed brake though. Some times it works and others it doesn’t. The jitters with the throttle was mild but now it’s so bad the plane is not flyable with this jitter. I forgot to mention the usb is plugged directly to the PC. I do have set screws installed to lock the arm to the pot stem so I doubt this is slippage. I will try to remove two pots tomorrow and see if this helps. I will also look into getting the BU036A board and setting the all axis to turn between 66 and 250. Thanks for the tips, I will let you know if this works.
Hello Kevin,
That's right I did a direct connection to pot didn't I. So it should move the designed 66 degrees, not ideal but I guess thats why it worked for me and others. Is this pot slipping on the stem?
To improve this a mod will be required, it would be much better to make the pot turn from 66 to 250 degrees.
As for the board, take the pots down to four and see if the jitter goes away? If so buy another one or invest in a leobodnar BU036A board.
On the cheaper micro boards, the ADC is split the more axis you utilise. So by reducing the axis, the ADC/Jitter should become more stable. Has it always been like this?
Karl,
Thanks for your quick response. I did send you the chat message. I am using the KeyYees Pro Micro ATmega32U4 5V 16 Hz Micro USB development board. I am using a single board but can use multiple if this will resolve the issue with the micro board. If I need to get a different brand/type board I can also do that. As for the speed brake, I have it set up the way you have it in the in the build. I am not aware of any gear in the V3 of 737 throttle quadrant. You can respond here if its more convenient but I can definitely Whatsapp for more help. Thanks again for your support, I await your response.
Hello Kevin,
I hope this was you that sent me a website chat window message, but as you were not registered, I can not reply. First which card are you using Leobodnar or Micro? The jitter appears to come from the power supply reference line. For most this is from an externally powered USB hub. If you have one of these, try plugging the unit straight into the computer.
If the problem is still there, then they're probably is an issue with the board/ wiring.
If you are using an Arduino micro board depending on the manufacturer, will also jitter when two many axis are used at the same time. Some people have now reported they use two micros and only four channels on each board to stop the jitter.
I can only suggest disconnecting each channel one by one to see which goes away. Please let me know how you get on and if you want direct help, just watsapp me on +673 7207616. I too am very interested to see what is causing this?
As for the speed brake, this is the first I have heard of this issue, but I can instantly understand this. It sounds like I have not got the gearing ratio correct. Ideally, pots need to move their full range for good input resolution. If it's only moving the pot by a few degrees, then it will cause the issue you have stated. A mod may be required for this correction.
Kind Regards Karl