In April of 2015 I found a Kickstarter called Bluz which offered a cloud-connected Bluetooth LE development kit that could be run off a coin cell battery for months or even years on end. The Bluz is very similar to a product called the Particle Photon released earlier last year and the Photon has quickly become one of my favorite development platforms for developing Maker projects. I figured that a Bluetooth LE dev kit would be a great addition to my maker tools.
After a bit of wait, it arrived on my doorstep and I figured that I would record an unboxing video and a simple test with the Bluz.
Since I pledged $49, I received what they call the Wearables Kit which included one Bluz dev kit, a Coin Cell Battery Shield and an Accelerometer shield.
The accelerometer shield that I received was not a custom Bluz created one, but actually a Sparkfun branded shield that I had already purchased on my own (an extra never hurt).
The coin cell battery shield is unique to the Bluz and allows it to be powered off a single coin cell battery. Included in this shield is an on/off switch that is surprisingly missing from the number of other battery shields that I’ve bought and tested.
The Bluz itself looks very similar to the Particle Photon and actually has the same footprint so that it can take advantage of the same shields as the Photon. It even piggybacks off the Particle’s online development tools and the same deployment pattern (aside from the need to be hooked to a gateway that I’ll talk more about later). One big difference in the immediate presentation of the Bluz is that it does not have a micro USB port for powering it. This is partly due to the fact that it can supposedly last longer periods of time on very little battery and its primary purpose is to not be continually connected to an outlet. The’ recommended method of powering it is to use the coin cell shield, or the VIN, or 3.3V pin
For my unboxing, I didn’t have a method of powering it through the Vin or 3.3V pin directly or a coin cell battery lying around, so I decided to use a Particle Shield Shield in order to breakout a DC Power connection (which ends up powering it through the Vin pin anyways).
The major thing to know about the Bluz is that it needs to be connected to a gateway or the Bluz iOS or Android apps in order to communicate to the cloud. While there are plans to open source the iOS and Android connection code, they haven’t been released yet and this is a pretty big limitation for anyone like myself that wants to use a direct communication line between Bluetooth devices and the Bluz. However, Bluz sells a gateway shield that can be attached to a Particle that allows up to 8 Bluz to connect to it and communicate to the cloud.
Also, I have yet to test out the claim that it can last months or years on a single coin cell battery, but will be using it future projects and will be testing this out. There is one difference in the code that supposedly helps the Bluz achieve this feat. The code inside the loop function contains a System.sleep call in the default sketch.
//this, and only this...
I expect the Bluz to be a worthwhile investment and can’t wait to see what kinds of projects I can build with this low powered Bluetooth LE dev platform. I love that they leveraged the Particle ecosystem and online development IDE as well.
While I was creating my first build and began to put my first working prototype together, I figured I would document my parts, their prices, and explain why I chose them. I’ve split up the BOM into two parts, the electric longboard components and the board components which are usable on their own for a normal longboard. I decided to go with a single motor design for my first build (it seems fairly trivial to add a second motor in the future) and so far it’s been handling pretty well on hills. The only downside is that sometimes if I lean all the way to the left, the right back wheel comes off the ground slightly and I lose the driving traction. For more info about the trade-offs, check out my previous post.
The way a typical electric longboard works is, you (the rider) use the transmitter to speed up or slow down. The transmitter interacts with a receiver that is hooked up to the ESC (Electronic Speed Controller) which interprets the signal and turns it into a motor signal. The ESC needs to be hooked up to the battery for power since the ESC is what drives the motor. The motor then turns a gear which is hooked up to a belt that will then turn another gear that is attached to your wheel. This is how your longboard will gain movement.
5065 designates the size of the motor and is a common size for electric longboards although they typically have a smaller shaft. 170kV designates the torque the motor can produce (the smaller the number the higher the torque, but the lesser it’s top speed).
$25 – Wiiceiver – (Not needed if you are using the VESC)
A way to control the input to the ESC coming from the wii nunchuck
I used this in the interim while I was waiting from my VESC to be made and shipped to me. With some configuration it turned out to work decently well. I was able to ride it on flat or a slight incline, but with less power and it would cut off if the motor started to draw too much power.
DIYElectricSkateboard sells an aluminum part for the motor pulley and I figured that since it’s the part coming off the motor shaft and is only connected by two set screws, it makes sense to get this part made of aluminum to handle the stress.
Originally based off a 9mm pulley model, I had to add bigger holes for stronger screws and a couple other changes. I will link to the design I put together for this part once I’ve tested it and made it fit reliably.
This works out well and is made of aluminum. This can be replaced with a cheaper non-adjustable mount, but I didn’t like the idea of welding on a mount to my longboard trucks and had not ability to do the welding.
Due to my choice of wheels, these had to be altered in order to fit them (I used a file to make a bit of room for the screws that hold the gear onto the wheel) If I were to do this again, I might try the Paris trucks since they are more symmetrical.