i managed to get the outline, now i need to define the components that the board will have. my first draft was in a sheet of paper, without knowing the real cost of any component (at least the real and updated price of each component)

my first idea was this

• 6x5 LED matrix4 user buttons
• 1 Hall effect Sensor
• Any microcontroller
• 2 Shift registers
• ICSP header
• I/O pin header
• 2032 battery

as far a I know any microcontroller and almost any IC can be powered by a single cell battery, i didn't test this theory so far, my experience in this field is just a keyChain i made (https://github.com/Rheyd/Keychainino-RT).

so after long hours of searching in Newark, I found at least some parts with nice prices, the problem, not all the parts were cheap, or available in SMD, the 2032 battery, and the battery holder, this parts were or too big or expensive, so i decided not to include them, instead i would use heat shrink tube on the battery and .1" headers, this will reduce the cost of the badge.

i keep searching and testing but mainly searching