The Inaugural Post and my DnDLED Project
I decided to start posting about my personal projects, since I like build random stuff and thought it'd be fun to share. The site's still a little bit under construction, but I figured might as well start posting, right?
Anywho, first up on my project list is an idea that came from multiple requests at work for a do not disturb light for your monitor/laptop, similar to Luxafor's idea. It's simple enough and seems like a fun little side project.
In today's open floorplan at work, you're constantly interrupted with distractions. Headphones used to be the defacto "Don't mess with me" standard, but it seems that it's no longer effective. My DnD LED device won't have BT or all the fancy ID work...just a couple LEDs and a button plus some motion sensing. Here's the gist:
USB 2.0, type-A
3x RGB LEDs on PWMs
Battery + charging circuit
Ability to place on monitor (battery) or laptop (charging)
Proximity sensor (for power saving)
3.7V power (LiPo battery)
Runtime: 2 days (48 hours)
I started with the runtime, since batteries are fun to calculate. I was thinking Neopixels to start, but based on their current draw using Adafruit's calculations I thought better of it, especially if I want to stay small. Here's how it went down:
Assume Neopixels run at 75% (link above), so 45mA * 3 = 135mA
LED controllers: 2mA * 3 = 6mA
MCU = 10mA (assumed)
TOTAL: 151mA (@ 3.7V)
My initial runtime req needed a 7200mAh battery (9000mA with 25% overhead) - that's YUUUUGE!
Let's try 3 workdays (x8 hours) instead; 4500mA - still a large battery/pack (heavy)
Needless to say, I switched to some basic RGB LEDs I'll PWM myself and run at a little lower current (~5mA per color) at expense of brightness. I'm gonna play with the currents and see what looks best.
Here's the current parts list and devkits I snagged:
Battery - Adafruit 3.7V 350mAh LiPo
Charger - Adafruit v1 Micro Lipo
RGB LEDs - SunLED XZM2CRKM2DGFBB45SCCB LEDs (via DK) - will make Othermill adapter
ATTiny44 MCU - Using the DIP version for dev (via DK)
Push button (have a million of these)
Proximity Sensor - VCNL4010 Proximity Sensor Kit
I'll keep you posted on my adventure with this project...next up I need a 3D printer :-)
Be sure to check in on here and the project page for more info.
Until next time!
P.S. The links aren't showing up in a different color on the site, will fix that. I promise they're there!