I decided to explore the artistic PCB realm and the map location pin became the theme.
A reverse mounted red LED, powered by a CR2032 coin cell, is shining through the PCB to provide a bright homing beacon.
Soon also available in blue.
The 1st installment is the classic maps pin inspired by your favorite 'show me the way' tool. The 2nd version has the outline of the more modern icon that can be found everywhere by now, even on my milk carton.
The reverse mounted LED is driven by a 3V coin cell through a simple 200 Ohm current limiting resistor. This provides ~5mA for the LED to balance brightness against battery life. A micro-switch can turn the LED on and off without the need to remove the battery,easily accessible on the top of the pin.
The batteries I have tested lasted more than 6 hours at reasonable brightness with a measured current of >2mA. And then it is running for another 24 hours at 2 to 1mA and still the LED is shining considerably bright through the PCB.
A circuit for a quasi-constant current supply is also designed onto the board, to run the LED from 5-20V without a battery. Here the LED can also be controlled by an additional external signal. This requires wires soldered to the pin and makes not as mobile but would be a good option for a more permanent wearable installation. Details about this circuit are documented here.
The boards were manufactured by Seed Studio (Classic version) and JLCPCB (Modern).
They are not_a_badge and if you really like them, they are available for sale in my Tindie shop .