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Adafruit Foot Pedal / Potentiometers
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Adafruit Foot Pedal / Potentiometers

by ZombieSlayer on Mon Jun 07, 2021 8:16 am

Hi all! I'm new to Adafruit and here goes my first question. I'm looking at adding the Adafruit Foot Pedal Potentiometer to my Rollplay Kids Vehicle project and I'm wondering if it would be a good fit. I'm using the MDDS30 motor controller from Makermotor which has a 5V input for controlling speed that I want to use the foot pedal for. I see that the Adafruit Foot Pedal resistance only goes down to 1k. My first question is will this decrease the upper range of my output? Second question is if this is the case is that why it says to use a "pull up resistor"? Next question is how would I wire up the pull up resistor? I'm new to the idea of pull up, pull down resistors. Lastly, would there be any performance issues or any issues at all with adding a master potentiometer (0-5k?) in series with the foot pedal and pull up resistor as a way of limiting the top speed of my project?

ZombieSlayer
 
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Re: Adafruit Foot Pedal / Potentiometers

by dastels on Mon Jun 07, 2021 10:45 am

The "pullup" really isn't in the classic sense. It forms the upper part of a voltage divider with the potentiometer in the foot pedal. The potentiometer just provides a variable resistance. To turn that into a variable voltage which can then be read, you need to make a voltage divider with another resistor. Then as the resistance decreases, the voltage between the resistor and potentiometer goes lower.

Can you link to the motor controller?

Dave

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Re: Adafruit Foot Pedal / Potentiometers

by ZombieSlayer on Mon Jun 07, 2021 11:45 am

https://makermotor.com/pn00218-cyt14-mo ... ou-mdds30/

My 5V is coming from the RC pin and the potentiometer wiper goes to AN1 & AN2.

ZombieSlayer
 
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Joined: Sat May 29, 2021 11:28 pm

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