I need to use a linear actuator for a project. From what I understand, the position feedback comes from a potentiometer. Here is an example:
One more example: https://www.servocity.com/html/25_lbs__thrust_linear_actuator.html
Two questions:
1) How does one get the actual position via, say, a microcontroller? It looks like I need to measure resistance, I don't know how to do that on an Arduino.
2) Internally how is the linear position correlating to a potentiometer signal? Is a gear near the end of the gearbox turning a pot nob essentially?
Thank you.
Best Answer
No, you don't measure resistance, you measure voltage. Apply known voltages (like 0V and 5V) to the two "reference" lines, and measure the "signal" voltage. There's an ADC in the Arduino to do that.
Internally ... a rotary pot is one way to do it. A more accurate way would be a linear pot running the full length of the actuator. How yours works I can't say.
If you needed an accurate position you'd use digital scales like a DRO or calipers instead.