Today was the final day of our Wired Up! program, and the students wrapped up by bringing together everything they learned over the past three sessions. They combined their understanding of electronics, breadboarding, and Arduino programming to create circuits that respond to real signals, such as their own heartbeats.

We began with fading LEDs using Pulse Width Modulation. Instead of simply turning lights on or off, students learned how the Arduino can switch an LED very quickly to make it appear to glow brighter or dimmer. By adjusting numbers in their code, they could create slow fades, quick flashes, and gentle pulsing patterns. It became clear that code and hardware work together to shape what we experience.

Then, we moved on to the highlight of the day: measuring heart rate using a pulse oximeter. The students placed their fingers on a sensor that shines a gentle green light through the skin, and as blood pulses, the amount of reflected light changes. The sensor produces an analog signal, which is a smooth electrical pattern that varies continuously. The Arduino performs analog to digital conversion to translate that smooth signal into numbers it can read and use to calculate heart rate. Students watched their pulse appear on the screen, and many tried small experiments such as doing a few jumping jacks, practicing calming breaths, or even testing whether telling the truth or telling a playful lie would change their heart rate.

Seeing their circuits interact directly with their bodies created real excitement and a sense of discovery. It was a powerful way to end the programming with curiosity, creativity, teamwork, and a new sense of confidence.

We are so proud of these young engineers!