This is a sub-$10 (assembled) shield featuring a 4-digit 7-segment LED display that can be connected to virtually any microcontroller. Schematic and BOM are available, and making Arduino sketchs available is the next step on its journey.
Board and schematics avaiable in the links section
7 Segment LED display
COM-09483 or equivalent, common Anode 4-digit, any color
I am a very active member of the "Arduino Brazil" group on Facebook (we are already 13k+ members!!); you guys have no idea on how much is done in that group, and how much I learn from there every day.
One of the members I recently met gave me the idea of making a 4-digit 7-segment "shield" that could be used independently of Arduino (featuring a different form factor). This guy resells in Brazil stuff he buys from Aliexpress, so I assume he knows what he wants (and knows what is available out there).
After a bit of [Google Images] research, I convinced myself that the available shields for that product were virtually inexistent, and decided to give it a try on making my own product.
So what you guys are going to see here is the making of a 4-digit 7-segment LED display using the well-known 74HC595 shift register (for pin saving reasons). My main goal is to sell some of those boards (when ready to it) and make a bit of money. But of course everything will be open-source, since I am not going to reinvent the wheel here.