This implements a little calculator with 7 LEDs as output (applying a shift-register), a M5Stack-Atom-Lite as the MCU and its button as input.Usage
Select the first number by cycling through digits 0 to 9, minus-sign "-" and decimal point "." by short press. To enter another digit double-press. To finish the number and get to the operator selection apply a long press.
Cycle through the operators plus, minus, mult and div with a short-press and leave to the input of the second operand with a long press. Enter the second operand like the first one.
If you then long press to finish the number, the result will be displayed.Example
In the example of the video you can see the input of the operand "3" followed by the selection of the mult operator ("x") followed by the selection of digit "5" as second operand. The result 15 is displayed as "=15".