Potentiometer ECE4180L4

Simple Potentiometer Demo for mbed

Hello World

Import programECE4180L4_Pot

"Hello World" program for using potentiometers with mBed. ECE4180 Lab 4.

Last commit 10 Mar 2015 by Jonathon Deriso

Library

Import programECE4180L4_Pot

"Hello World" program for using potentiometers with mBed. ECE4180 Lab 4.

Last commit 10 Mar 2015 by Jonathon Deriso

Notes

Potentiometer Basics

In the world of electronics, potentiometers are informally referred to as pots. The most common type of pots are three-terminal resistors with an electrical contact that either slides or rotates along a resistor (or in some cases between different resistors) in a voltage divider circuit to provide variable resistance (and variable voltage output).

pots

These simple pots include three leads - the outer two should be connected to 3.3v and gnd (the Vout and Gnd pins on the mBed) and the inner lead should be connected to p20 (an analog input).

/media/uploads/jderiso2/pot_cap.png /media/uploads/jderiso2/wp_20150310_001.jpg


Here is another quick demo idea with less parts to hook up. The analog input from the pot, dims the LED using PWM. It is easy since both AnalogIn and PwmOut are scaled from 0.0 to1.0 .

#include "mbed.h"
PwmOut myled(LED1);
AnalogIn mypotentiometer(p20);
int main()
{
    while(1) {
        myled = mypotentiometer;
        wait(0.01);
    }
}

pot
Sparkfun's small 10K pot will plug directly in a breadboard. The spacing on the 3 inline leads lines up well. The knob is also just large enough to turn without using a screwdriver.

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