Section 3.5 - 3.3V vs. 5V Pins


Why are there 2 separate power pins?

In this lesson, you’ll delve into the discrete power ports on the Arduino, focusing on the 3.3V and 5V outputs and understanding their differences beyond just voltage levels. You’ll begin with a demonstration in TinkerCAD, where you’ll create circuits that power an LED using both the 5V and 3.3V ports. It’s important to note that no code is needed for these circuits, as these pins are always “active,” functioning similarly to a battery that provides constant power. Next, you’ll explore the actual differences between the 3.3V and 5V outputs through slides. The 5V pin can deliver more power and is typically used for components that require higher voltage, such as standard LEDs, motors, or sensors. On the other hand, the 3.3V pin is suitable for lower power components, like certain sensors and microcontrollers that are sensitive to higher voltages. You’ll also learn about current limits; the 3.3V port usually has a lower current capacity compared to the 5V port, which means it’s essential to choose the appropriate voltage for your components to prevent damage. This comprehensive understanding of the power ports will enable you to make informed decisions when designing circuits with the Arduino.