Did you know you can power BlinkMs or BlinkM MinMs off two 3V coin cells? Here is a tiny 3d-printable coin cell and header socket holder for BlinkMs and BlinkM MinMs. It snaps together and has mounting holes to turn it into a pendant or mounting additional diffusors for the LEDs.
And you don’t need many parts to build it:
– one each of plastic pieces here (see the STL files on Thingiverse)
– two CR2032 3V coin cells
– one 4-pos female header socket (Digikey S7037-ND or equivalent)
– two short pieces of solid wire (old resistor leads, 26 gauge wire stripped, etc.)
1. Push the 4-pin socket into the hole until it stops. It should friction-fit in without any need for glue.
2. On the bottom, feed the two wire pieces in as shown in the photos, and solder them to the two pins on the header socket. These wires become the battery terminals.
3. Bend the wire battery terminals so they make good contact with the cells.
4. Insert coin cells, snap together top piece.
5. Insert BlinkM and watch it play its light sequence.
6. To protect the back, put a small piece of gaffers tape or similar over the terminals.