Planning a new apartment building is kind of like a math problem. Developers calculate an array of costs to help determine a rent that will generate enough revenue to make a project feasible to build.

But we can’t deny this Arduino calculator project by [Danko Bertović] would look good sitting on the bench. In the video after the break, [Danko] walks us through the creation of the calculator ...

This project uses a 4 4 keypad (shown in Figure 6.43) and an LCD to design a simple calculator. Figure 6.43: 4 4 keypad Figure 6.44 shows the structure of the keypad used in this project which ...

[Eric] and the late [Richard Ottosen] have been incrementally developing various DIY calculators — this paper from the 2005 HHC conference is an excellent overview of the early project.