Data Sheet

Introducing tinyLiDAR
The Maker-Friendly Laser Sensor
Have you heard of LiDAR? Chances are that you probably have. It’s fast becoming the new buzzword
in the news lately. It’s the cool new tech that can be found in all sorts of new products like driverless
cars, drones and even smartphones.
So what is it? LiDAR stands for "Light Detection and Ranging" and if you Google it, you’ll find a bunch
of references to long range airborne surveying systems. That was the old-school LiDAR. Today’s
LiDAR is much more compact, lightweight and lower power so its finding its way into many areas
that were unimaginable in the past.
LiDAR works just like RADAR but instead of sending out high frequency radio bursts, it uses infrared
laser light.
Professional LiDAR systems like those used on driverless cars incorporate ultra-fast Analog to
Digital converters, rotating platforms and high-end optics so they’re generally not very hobbyist
friendly. Fortunately, for those that don’t need the ultimate in ranging distance and measurement
speed, there are simpler and lower cost options.
A company called ST Microelectronics has created some of the world’s smallest time-of-flight (ToF)
sensors which have been integrated into more than quarter of a billion smartphones and computers
to date. You probably have one in your phone now.
Their first gen product was called the VL6180X and it could measure up to about 10cm but their
more recent, second gen ToF sensor is called the VL53L0X and it can measure up to 2meters thanks
to its built-in Vertical Cavity Surface-Emitting LASER (VCEL) and matrix of over 200 high sensitivity
Single Photon Avalanche Diode (SPAD) receivers. This particular ToF sensor is what we used in
tinyLiDAR.
Of course, measuring the speed of light needs some very high performance electronics. Thankfully,
all of this is integrated inside of the VL53L0X sensor. In fact, this little sensor can resolve all the way
down to a few
pico
seconds which means it’s capable of providing mm level accuracies. Pretty
impressive for such a small device!
Since these sensors were designed to be used in smartphones, they are typically paired with high
performance processors. Unfortunately, the Arduino Uno is not considered high performance.
Remarkably, however, there are some bright individuals who have managed to make the Uno work
with this sensor. But, as surmised there are some performance/feature limitations and the resulting
library eats up quite a bit of Arduino’s precious little memory space.
The inner workings of the VL53L0X is not well known publicly. ST has developed this technology
which they call FlightSense
TM
on their own and patented it so it’s not surprising that they would want
to keep the details under wraps/under NDA. But to give them some credit, they have made public, a
lengthy 157 page Photonics Abstraction Layer (PAL) API spec for this little sensor. For most non-
career programmers, however, it’s a bit much to take in.
Like all innovative products, the idea for tinyLiDAR came along the way of building something else.
Some time ago, we had a need for an accurate, low power and inexpensive proximity sensor.
tinyLiDAR Reference Manual rev1.26 3