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Sep 13

5 months

Awesome weekend @ MakerFaire Zürich 2017

"The greatest show (and tell) on earth"

Last weekend, on September 9 & 10th, was the Zürich Mini MakerFaire - a "family-friendly festival for digital crafts and new technologies, with a focus on making, learning and sharing".

This was the second year the event was held in Zürich's Dynamo Jugendkulturhaus - a beautiful and atypical location on the bank of the Limmat river.

It was impressive to see how many people showed up for the event - way more than I had expected. Also impressive was the diversity of projects presented by the various teams, including 3D-printing, Steampunk contraptions, cosplay, electronics and DIY workshops.

Below are some pictures from the event:

@letootoot posing next to the giant maker lion

Some awesome projects presented during the weekend

The Dooba table, with Gadget Kits and Fiddles on display

Preparation for the event

The weeks leading up to this weekend have been quite intense for me, trying to get as many prototypes and kits ready for demo.

Printing enclosures & getting prototypes ready

Awesome feedback

Throughout the weekend, we received some very positive feedback regarding the ioNode, the Fiddle, and other products.

One of the key points revealed by this was the importance of Wifi connectivity. Many people indicated that while they appreciated the idea of a tiny gadget such as the Fiddle, they would have really liked to see some Wifi included in there. We received pretty much the same feedback for the kits.

I now know how to improve the Fiddle and have started working on a new version, a few millimeters longer, with Wifi and MicroSD included.

Working on a new Fiddle with Wifi and MicroSD

New libraries and tutorials

Now that I have a little more time to work on the SDK & documentation, I've started adding new libraries and tutorials.
Already available:

  • PWM (Pulse Width Modulation)

  • RGB LEDs

I've also completed the "client" part of the esp8266 library, offering quick and easy access to the internet through this very common Wifi module from Espressif (which is also the one that will be included in the new Fiddle).

I will continue to add more libraries and tutorials over time, so sign-up for the newsletter and stay tuned!


Aug 23

6 months

Getting ready for Maker Faire Zürich 2017

It's that time of year again

I can't believe it's already been a year...

The second edition of the Zürich Mini Maker Faire will be held on September 9 & 10 2017, at the Dynamo Jugendkulturhaus in Zürich.

Last year was an incredible success, with many projects presented in a wide variety of fields.

Let's hope we can have an even better experience this year!

Almost there

I'm currently working as fast as possible to get as many prototypes as I can ready for demo.

Here's a little sneak peak of what I'll be showing off during this event:

The Fiddle with some demo apps

Shiva MP3 Player

Trax Tank Controller

Of course, the ioNode itself


Aug 22

6 months

Introducing the Fiddle - Tiny UI for ioNode


I've often found myself struggling with UI for embedded projects.

User interfaces generally eat up a lot of board space. I thought maybe it would be interesting to have a "UI-as-a-module" that I could simply patch onto anything.

It turns out this was not only a good idea, but actually opened the way for more!

By attaching this module directly to an ioNode (with nothing else), you get a small, simple, elegant USB gadget on which anyone can develop apps.

UI has never been easier...

I gave my friend Mauricio Togneri the very first Fiddle I had put together. It was just a Fiddle & ioNode combo.

Two days later, he came back with this:

Snake - such a classic!

With no prior knowledge of AVR development or OLEDs, he managed to implement the classic Snake game in just a few hours using the documentation and tutorials available at - impressive!


The ioNode + Fiddle combo looked so nice, I could not just leave it like this. I fired up Blender and modeled a simple enclosure that my Ultimaker 2 Go printed perfectly in just under an hour (58 minutes).


Aug 09

6 months

Shiva mp3 player is complete!

It took a few iterations...

It's been a while now that I've been talking about the Shiva mp3 player.

After going through MANY iterations on the hardware, the firmware and even the enclosure, I finally have something "complete".

For those who don't already know what we're talking about here: the Shiva is a fully open-source portable mp3 player that anyone can build. Both the hardware schematics and complete firmware source code are all available on

It is based on the ioNode, a tiny but powerful embedded development platform, as well as two additional modules:

  • Nomad, a tiny all-in-one (boost+charge) LiPo battery solution

  • Aecho, a complete MP3 decoder module with stereo jack output and unamplified line out

The firmware is built using the Dooba SDK.

Current status

Final enclosure design

Slightly different enclosure with raised borders

Most improvements have already been presented in a previous article: New & improved Shiva mp3 player.

The Shiva now features a 1000mAh LiPo battery, allowing up to 8 hours of continuous play. This is twice the initial 500mAh capacity.

Instead of software bit-banging, SPI is now used for communication with the MicroSD card and MP3 decoder, allowing for much higher data rates. The Shiva can handle MP3 up to 192Kbps without breaking a sweat.

The UI was greatly simplified, now featuring a 128x32 OLED display, a 5-way tactile switch (mini-joystick) for navigation, and two buttons for volume control.

Finally, the enclosure is now a very "comfortable" single chunk of plastic which is simply press-fitted on the PCB. No glue required.

Where we came from

While I didn't take pictures of every single attempt, below is a gallery presenting the major steps since the very first version.


As soon as the Shop opens, the modules presented here will be available for purchase, so truly anyone can build their own portable mp3 player and enjoy hacking it!

In the meantime, subscribe to the newsletter to get all the info!


Jul 20

7 months

New & improved Shiva mp3 player

Time for an upgrade!

I have been using my Shiva portable mp3 player for a while now.
Awesome as it may be, there were a few things that I wanted to improve on this little beauty.

Clumsy UI

Having all these buttons made the Shiva look like a half-finished product. But that's not even the real problem.
7 tactile switches (5 for browsing and control, 2 for volume) sure eat up a lot of physical space.

I tried to use smaller switches and pack them as tightly as I could, but just ended up with an unusable product: the switches were so small and close together that it was nearly impossible to press them.

These tiny switches are a nightmare!

I decided to go another route: replacing the 5 directional buttons by one 5-way tactile switch.
This turned out beautiful and very comfortable to use, while drastically reducing the necessary board space.

OLED overkill

Another major issue was the OLED display itself.
I had been using 128x64 OLEDs from Adafruit, which cost about 18 CHF (a lot of money) and are pretty bulky.

Also, 128x64 is way too many pixels for a simple mp3 player - taking too long to refresh (causing some delays in the audio processing at times) and eating up more power.

I switched to tiny 128x32 OLEDs from random Chinese suppliers. These are much smaller and just a better fit for the Shiva.

Building a better mp3 player

While I was waiting to get my new boards, stencils and parts from OSH Park, OSH Stencils and Digi-Key, I started putting together some Nomad and Aecho modules:

Gotta love the yellow header :)

Soon after that, I received my boards, stencils and parts and was ready to start building my best mp3 player so far.
The result was very nice:

This thing is beautiful

Demo time!

Here's a little video showing off the new UI:

Get the source & keep in touch

Everything here (schematics, boards, firmware source code) is available on the Dooba Source website. Go download it and start hacking!

Also, don't forget to subscribe to the newsletter to get all the updates!