This is a fairly specialized piece and is seen as a starting point for more flexible designs. It breaks out the 18650 +3.7V (to 5V on D1M BLOCK) and GND (to GND). The 5V pin on the Wemos D1 Mini is connected to a regulator that drops the voltage to 3V3 for that pin on the D1 Mini. This design also supplies brackets for mounting the power supply on a bike helmet. As with all the D1M BLOCK's, the pins and offsets are built for easy stacking of multi-block circuits.
Step 1: Materials and Tools
- The Wemos D1 Mini Protoboard shield, short pin male headers long pin female headers
- 3D printed Housing and Brackets
- SPDT PCB switch
- Hot glue gun and hot glue sticks
- Strong Cyanoachrylate Adhesive (preferably brush on)
- 200mm x 4.5mm cable ties
- Self-tapping button head screws ~5mm diameter by 15mm
- 3D Printer or 3D Printer Service
- Soldering Iron and solder
- Hookup wire
- Basic electronics tools
Step 2: Assembling the Circuit
- Place SPDT on top as shown.
- Solder Pins off on bottom
- Cut excess off 2 outside pins.
- Insert Red and Black wires from top into through-holes.
- Solder wires of on bottom.
- Bend center pin on SPDT to Red wire and solder.
Using assembled PCB, short pin male headers long pin female headers:
- Insert short side male pins from bottom as shown.
- Solder off on top.
- Insert female headers into male headers on bottom
- Using Cyanoachrylate, glue headers together when flush
Step 3: Assembling the Housing
- Insert PCB into housing, keeping pins centered.
- Hot glue PCB and wires to Housing
- Insert battery holder into Housing
- Straighten pins (if needed) and trim off flush with housing.
Step 4: Connecting to Bike Helmet
- Fasten wedges to Helmet with cable ties
- Fasten Housing to wedges with self-tapping screws
- Insert D1M WIFI BLOCK