A 5V LED should run for a predefined time period once a button is pressed. The LED should be illuminated for the same duration as the button is pressed, but only once the button is released and illumination should last at least 5 seconds. The time deviation should not be more than 2 seconds. Since the controller needs to be positioned on the backside of a wood panel, only limited physical space is available (the smaller the better). A 5V power source is provided for. The project is part of an art project that is to be displayed on a music festival in the summer of 2020. At least 200 of these panels+controllers are needed, so cost should be reduced to a minimum.
Previously (prototype), an Arduino Nano was used. Now, cost and size need to be reduced further. What would be the minimal components required to complete this task?