Lab 10: Power Consumption and ATmega328P without Arduino
Clarification
Here are some details to make the circuits more clear.
- Dr. P needs to see that your LED is visibly ON in all three circuits.
- Vcc must be the same for both LED ON and LED OFF scenarios. (Don’t use a smaller Vcc with the LED off. Assume you are writing code for a circuit where you cannot just change Vcc all the time.)
- Circuit 1 must have a Vcc of 5 V for both LED on and LED off. This is a baseline, you want to know where you started from.
- Circuit 2 and 3 can have a Vcc down to 2.7 V, but only if the LED is visibly ON. (In circuit 2, the LED must be visibly ON with the USB cable disconnected from the Arduino Uno.)
Dr. P’s Best Power Values
In May 2022, here are the values Dr. P got without spending a ton of time optimizing. (You can do better!)
| Circuit | LED ON | LED OFF |
| 1 | 213 mW | 166 mW |
| 2 | 125.4 mW | 98.6 mW |
| 3 | 2.6 mW | 2.3 mW |
Resources
Watch/read the following resources prior to attending this lab. This information will teach you how to use lab equipment and provide suggestions and technical tips for successfully completing the lab.
- Textbook: Chapter 9
- Website: AVR Fuse Calculator
- Website: Arduino boards.txt file (includes fuse details of the Arduino programmed ATmega328P)
- Website: How to use AVR fuses
- Website: All you need to know about AVR fuses
This lab is licensed under creative commons as CC-BY-SA-NC. For more information, visit creativecommons.org.