Lab 1:
Potentiometer
Analog Control for
LED Brightness
Parts required:
1 Arduino
1 USB cable
1 Arduino proto shield
and jumper wires
1 LED
1 Potentiometer
1 100 Ω resistor
Estimated time for this lab:
15 minutes
■ FIGURE 7: Potentiometer LED
breadboard drawing.
Check off when complete:
❏ Build the circuit shown in Figures 7 and 8.
■ FIGURE 8:
Potentiometer LED breadboard schematic.
❏ Vary the pot angle and note the effect on the LED.
❏ Draw this circuit with arrows showing current flow.
❏ Calculate the current flow with the pot set at full right,
three-quarters right, middle, three-quarters left, and
full left.
❏ Calculate the voltage across the 100 Ω resistor at each of
these currents.
Lab 2: Potentiometer Digital
Arduino IDE (available at the article link):
Voltage Control - ADC
// A101_ch7_pot_voltage 5/7/14 Joe Pardue
In the last lab, we calculated the current with the pot
set at full right, three-quarters right, middle, three-quarters
left, and full left. We then calculated the voltage across the
int sensorPin = A0; // analog input pin
int sensorValue = 0; // store the analog input
100 Ω resistor for each of those positions. Now, we will
verify those calculations by using the Arduino ADC to
measure the voltage across the 100 Ω resistor.
Parts required:
1 Arduino
1 USB cable
1 Arduino proto shield
and jumper wires
1 LED
1 Potentiometer
1 100 Ω resistor
Estimated time for this
lab: 15 minutes
Check off when complete:
❏ Build the circuit shown
in Figures 9, 10,
and 11.
❏ Copy the following
program into the
■ FIGURE 9: Pot as rheostat drawing. ■ FIGURE 10: Pot as rheostat schematic.
70 July 2014
