Yaw Encoder Potentiometer Value
  • In your pdf document you mention that the yaw potentiometer needs to be between 1k and 4k. I have a Walkera 3D gimbal that has a 12k Yaw potentiometer. Can I use it as is or do I need to put in parallel a 6k fixed resistor to bring it down to a total of 4k?

  • No resistor parallel needed and it would not help anything. You could test the 12k potentiometer., probably it will work, but maybe has more noise and input resistance could cause unlinearity.
  • If noisy, I could always use a capacitor to filter the output. Would it affect loop stability if the pole is too low, like hundreds of Hz?
  • Yes, that should help, but too high value could cause problems, so might require some testing.
  • You can use 12k pot, but take care about shielding analog signal to prevent EMI noise. Filter capacitor may be used, too, but it will add a delay. You need to calculate its value to make 'time constant' of LPF to not exceed 4-8ms.
  • Alexmos,

    Thank you! That's exactly what I was looking for. Looks like 1uF should be what I need. Regarding shielded wires for analog signals I'm all for it. Since you may have dealt with these issues in the past do you have a source for multiple (2-4) shielded wires, which are also very flexible?

    On a related note, I fixed all I2C errors and now I've got an extraordinary stable Walkera G3D gimbal with the Alexmos 32 bits electronics. The Yaw holds very nice and because the Walkera G3D gimbal has the encoder potentiometer built-in, the mods to get the Alexmos electronics are quite simple. Thank you for a very impressive piece of hardware!!!