KiCad ⁽¹⁾

The idea for this project was a simple countdown timer to be used for various children's games and activities where the user interface was designed to be as simple as possible; the display was clear from across the room and provided a sense of urgency, with a clear notification when the time was up. I started from the need for a large bright display, which meant using the largest economically available 7-segment LED modules. Starting a timer should be as simple as pressing a single button with a fixed function, so there is no time adjustment (up/down) facility which can be fiddly and non-obvious to use. Those often require long presses to get into a fast increment mode and are not consistent in how they accelerate. Choosing the time periods at the start of the project meant that the front panel could be labelled. Seven periods covered the desired range of 10 seconds to 15 minutes and left one button to be used for cancel, making a nicely symmetrical 4 buttons arrangement down either side. A coloured bargraph display was designed to give a sense of what proportion of the original time has elapsed and how much remains, using 10%…