Lulu Monitor: Feb-Apr

This post summarizes the developments we’ve made on the Lulu project during February – April 2018.

Overall I feel there are two main different routes we could go for Lulu V2:
1) addressable LED
2) non-addressable LED

a-e: addressable LEDs
f: single LED
g: single LED with on-board transistor


– fixed address
– ready-made?
– DIY: ATtiny10?

Type of communication?
– 3 lines (1 interrupted) Neopixel, SPI
– 4 lines (2 interrupted) DotStar, I2C
I²C (for ‘Inter-Integrated Circuit’, protocol)
SPI (for ‘Serial Peripheral Interface’)


– single LED
– on-board transistor?
– charlieplexing


If we look at how the circuits for these different solutions look like:


Would it be possible to have an addressable with continuous data connection!?!?


Single LED and with on-board transistor:

Circular circuit:

Different angles:

The Bumblebee works both ways with no jumps!

E-Textile & Soft Circuit Criteria

– minimize need for “jumps”
– hand sewable connections – machine sewable?
– small footprint
– low-profile
– gradual transition from hard to soft?


– side-mount LED
– flat-mount LED + angled prism (can also help focus light)
– flex PCB?
– custom design (Bumblebee)


E-Textile Connections

– sewable
– solderable
– snap (plugable, removeable)
– press-fit (Aarchen, Lilypad Snapring, pouches+motorbaords)
– improve electrical connections (squishy material on PCB?)



Bumblebee = basically a 4 way tip-ring connector, except we want the conductors to be indented and isolation as “bumps”:

Snap breakout

Fiber-Optic Connections

Could we use spaghetti (Bucatini) as connector???


Sketching with Maurin

Sketching with Maurin

Sketching with Maurin

Sketching with Maurin

The different solutions we have tried so far:
E-Textile to LED to Optic Fiber connectors