What I want to do
I'm trying to generate a circuit board design for Public Lab's thermal flashlight project.
I'm using a fairly easy to find and inexpensive LED on the board -- but there was a concern that it might not be bright enough -- so I added three more! :)
If this isn't sufficiently bright, we might consider having a ring of LEDs around the entire board, perhaps?
I'm still learning Eagle, and this is my first attempt at adding what is called a 'ground plane' -- which makes routing easier, and generally helps to smooth out electronic noise in the system.
My attempt and results
Here's the latest schematic:
- four RGB LEDs -- all controlled by the same pin, and wired in parallel (perhaps in another version we could control all the LEDs separately?)
- a 32u4 Arduino-compatible microcontroller
- a footprint for a screw terminal and resistor that would allow for the addition of a thermistor (for use in the thermal fishing bob use case)
- a buzzer (for a cool geiger-counter like temperature effect -- or play a wintry tune if the temp gets too low)
- a holder for a coin battery, and a connector for an external Lipo battery -- both of which can be recharged on-board if the device is plugged into USB power
- two analog input / output pins have been broken out
- and RX / TX is also available (in case you want to interact with the board via a Raspberry Pi)
Questions and next steps
I'm going to look over the design files on github, see if I've goofed anything up, and then aim to order a test batch. If anyone out there knows Eagle and can review the design for any obvious flaws -- or has suggestions for improvement -- please do chime in!
Why I'm interested
I want to see if I can make a prototype before SNOWFEST so that we can see exactly how effective igloos are as insulation against the Vermont weather.