This week we began work on designing our own Micro:bit pedometers.
We first looked at a similar, existing product – a mechanical pedometer, and we played the roles of customer & engineer to decompose the pedometer and to work out what could go wrong and how the engineer could address this.
We took apart 2 pedometers and researched how they worked:
Early pedometers were entirely mechanical and they worked a bit like pendulum clocks (the ones with a swinging bar powered by a slowly falling weight). As the pendulum rocks back and forth, a kind of see-saw lever called an escapement flicks up and down and a gear wheel inside the clock (which counts seconds) advances by one position. So a pendulum clock is really a mechanism that counts seconds. The original pedometers used a swinging pendulum to count steps and displayed the count with a pointer moving round a dial (a bit like an analog watch). You fixed them on your waist and, every time you took a step, the pendulum swung to one side then back again, causing a gear to advance one position and moving the hand around the dial.”
This helped us to explore the concept of a pedometer, how we could make one that counts steps as accurately as possible and the best design. We talked about 2 other types of pedometers – Fitbits & Smartphones.
We discussed the sensors that a Micro:bit includes and how they work, and compared these to the sensors in a phone. This will help us to design our Micro:bit pedometer.
A few children kept their pedometers on until next week and have been amazed at:
- How easy it is to clock up lots of steps
- How accurately this old-fashioned pedometer measures steps (been comparing to their fitbits)
Did anything surprise you today?