A project I am working on requires temperature data to be sent periodically (about every 5 minutes) from a sensor node to a data logger using an XBee radio. The project requires the sensor to operate using battery power for two weeks. To conserve power, I built a 3.3 V breadboard Arduino with a efficient

For a recent project I used a a TSL235R light-to-frequency converter that outputs a square-wave signal with a frequency that increases the amount of light hitting the sensor also increases. There are several Arduino packages out there for using the ATmega328 to measure frequency but I decided to write my own code in order to

Interrupts are exactly what they sound like. They are events that cause a microcontroller’s CPU to stop executing a main program in order to execute a snippet of code on the side. As an example, here I discuss how the analog comparator on the ATmega328 (Arduino Uno) can be configured to generate an interrupt. Let

The Arduino IDE has many built-in commands to produce PWM outputs but directly setting the timer registers gives you much more flexibility and power. Below I show how to configure the 8-bit Timer/Counter2 on the ATmega328 (Ardunio UNO) to generate a 40 kHz square wave on Arduino digital pin 11. Why 40 kHz? I want