Perhaps you were introduced to the world of Arduino through one of our beginner Arduino projects and are now looking for a challenge. These five project ideas combine the Arduino platform with a variety of other technologies and applications. They are sure to stretch your skills as a developer while highlighting the versatility of the Arduino platform.

You can use an Arduino to interface with an iPhone or iPad. This opens up a whole new world of possibilities for home automation, robotics control, and interacting with connected devices. This project creates a simple interface between Arduino and iOS using a RedPark breakout pack. The connection allows you to create iOS apps that control Arduino modules without having to jailbreak or modify your iOS device. Electronics controlled by your mobile phone is becoming a popular method of interaction, and this Arduino project creates a simple prototyping platform for experimentation.

Use your Arduino to control a mood light, an LED light that lights up in different colors, so that the color represents the overall emotion of the global X users at a given moment. Make it light up red for anger, yellow for happiness, or any other color you like. With the project, you can quickly feel the mood of the world, or more precisely, the world according to X.

While it may seem frivolous, the project introduces the concept of aggregating data for alternative purposes. For example, by pairing Arduino with a web interface like X, you can track a number of useful public metrics. If you’re a brand manager, you could track the number of conversations about your product. By pairing a powerful web monitor with a physical indicator like an LED, you can give users access to a range of personalized data points that can be easily read and understood by anyone, regardless of software experience.