Hello, welcome to my blog! This is where I collect my projects and other thoughts!

This website is divided in these sections:

  • Arduino: hardware projects and my journey logbook in electronics;
  • Programming: all of the software I wrote;
  • Italy: stuff that is either in Italian or only relevant if you live there;
  • Blog: works in progress, thoughts, ideas, unit tests, documentation, and everything else.

You can find most resources via the sidebar or the header menu. Have a look around, follow me on social media to receive updates!

Leather EDC keychain 2.0 pattern

This keychain wallet features some pockets to hold everyday items. Options vary. I use to carry a Leatherman Piranha (which is TSA compliant but don’t be too optimistic), a pen, a comb, tweezers, some business cards. The key rings have rivets; for a once-in-a-while job you can try at the local shoe repair store to ask to apply the rivets for you.

My only note here is that pocket width should be adjusted based on what you want to put in it.

Leather glass case pattern, lined with rolled edges

This is the pattern I use to make glass cases. This pattern has rolled edges. They are tricky to get right, but they allow to line the case with fabric. I use Italian printed silk. The silk is glued using glue sheets.

The pattern has a couple concentric lines. The inner line is where skiving should start (this is the most difficult part). The fabric should be glued at least up to the stitching points.

If skiving goes wrong, you have the option to patch it with some other leather rectangle, like the blue one in these pictures. Or throw it away and start over.

Leather 40mm belt pattern

This is the pattern I use to make belts. It is meant for 40mm wide belts. It is fully stitched (no rivets).

A wedge is needed to shape the belt loop. I recommend letting the loop rest for 48 hours. Wetting the loop will probably bring better results. The loop length should be adjusted based on the leather thickness.

I also recommend thinning the leather on the part where the loop is, with the help of a skiving machine.

Leather magnetic cable holder pattern

Let my first pattern to be related to wires. It’s a cable holder. It’s meant to tidy up your cluttered wires. It doesn’t look like it came out of a datacenter.

This holder is designed to wrap a 10x20x60mm magnet, and stick to a magnetic surface (in the picture, it’s a magnetic glass wall). Dimensions might need a bit of adjustment as Chinese magnets tend to have impredictable sizes.

Leather projects and patterns!

I’ve picked up leathercrafting as a hobby for several years now. It is kind of my personal take on 3d printing; more functional, more elegant, and when done right your projects will last forever.

I have a bunch of original designs collecting dust, maybe sharing them here will be of use to someone.
For the time being, I’m not going to include detailed tutorials, but just the patterns.

There is a fee of 19.99€ per download, but just for today, it’ll be free.

Making things on a beach: bamboo tongs

Instead of solving sudokus, why not making something useful for the environment?

Did you ever go to a beach so far away from everything else, so isolated, so hard to access, to find out it is littered anyway? That’s not unexpected: isolated places are gorgeous, but they have nobody that looks after them. Do you remember when #TrashTag was trendy? I might be a couple of years late but I decided to took the matter in my own hands anyway or at least do my part of picking up some bags of trash.

The bamboo tongs are very effective at picking up trash from the sand (also for relocating the occasional jellyfish, if needed). You’ll find out that if you can see trash on the sand surface, it means there will be (a ton of) more trash below. Bamboo is pretty common on the seaside, it’s sturdy, and the tongs are long enough to make me feel safe whatever I pick up.

Making the tongs is simple, but here is a step-by-step guide anyway. Be careful with sharp tools.
Find a bamboo stick with at least 2 uncracked sections, ideally around 2cm thick, at least 20cm long.
Cut it sideways so that you keep a “knot” about 2cm from the tip.

If your Swiss army knife has a reamer, it’s a good time to use it as a drill tip to make a hole. Do it about 2cm from the knot, on both sides of the bamboo.

Then with a knife make a cut at the side of the hole, pointing down the long end. The round hole will prevent the crack from going upwards.

You’ll end up with a chopstick-like bamboo strip, that you can discard.

Starting from the round hole again, cut diagonally. Try to cut in a straight line. Don’t overdo it and don’t rush it. Don’t cut the bottom away. Make several incremental passes. The bottom end of the tong should be almost flat.

Pinch the tong to check it is straight. Flatten the contact points so that the whole border touches each other.

That’s it. Don’t forget to bring a small bag with you; the best places to go don’t have trash bins, so a bag is always handy to clean after yourself, and with a simple tool you can also leave the place a little better than how you found it.

The laws of cooking as Venn diagrams

I’ve been reading Justin Warner’s excellent cooking book The laws of cooking: and how to break them.
I tried to make an extreme summary of the laws, and represent them as Venn diagrams, where each set in the diagram is a set of flavours that work well together according to the book. Do not worry, it’s not a spoiler: the book is still very worth buying.

I was expecting something more complicated to show up: only 3 flavours belong to more than one set (if we don’t count “Salty”, which goes well with everything). And this is including a slight personal “update” to the laws that I made, by splitting the “sour” flavour in two different flavours: “sweet” and “acid”.
Also, for those of you that try to avoid fat foods, I have bad news.

Realistic, continuous hi-hat control module for Hydrogen (for edrums with CC pedal, with bonus cymbal choke)

I wrote this article back in 2012, to workaround some limitations in the Hydrogen drum machine. It was impossible to control the hi-hat from closed to open (and viceversa) seamlessly, so I wrote a MIDI router to fix it.

Here you can see it in action:

I wrote this script mostly in order to improve the Hydrogen hi-hat feeling, but I accidentally added a couple other features too.

It can seamlessly switch from closed to open hihat (and vice-versa), supports cymbals choke (both the ride, crash and via the hi-hat pedal), and slightly improves the dynamics range.

To use it, you will need:

  • an edrum (I used a Roland TD9)
  • several (at least 3) hi-hat samples from closed to open, i used those http://www.freesound.org/people/TicTacShutUp/packs/17/ plus some closed hihats from other sets
  • mididings (on Debian or Ubuntu, sudo apt-get install mididings)
  • this script: https://github.com/simonebaracchi/continuous-hh (if you have less or more than 7 hi-hat samples like I did, you’d better modify “hihats_pedal_range” in this script to make it match your number of samples)
  • in Hydrogen, setup your kit like this:
    • first sample from the top: footclick (will be note 36)
    • sample #2: completely closed hihat (will be note 37)
    • sample #3: slightly less closed hihat (will be note 38)
    • … and so on…
    • then, all the other instruments (it is crucial that all the hihats are consecutive, and my script expects to find the first on note #37)
  • in Hydrogen, disable all mute groups (they don’t sound great for this purpose), disable “ignore note-off”, and make it listen to channel 9 if it’s not already so (channel 10 does not seem to be good for noteoffs, maybe it’s faulty in mididings, i don’t know)
  • in your edrum: use channel 9, set footclick to note #36, hihat to note #37 (both open and closed if you have both), and hihat pedal to CC#04 (it’s called “foot(4)” on mine)

launch script (“mididings -f <script>”), route your midi data into mididings, then from mididings to hydrogen (or another sequencer, maybe for recording, if you like), start banging on your edrum, you should be good to go.

There used to be a discussion about it on the Hydrogen forums which are now unavailable, but you can still read it thanks to the Internet Wayback Machine.


Can you drill a hole bigger than 1/4″ with a Dremel? Short answer: NO

At least, not in one single go.

I’ve been looking the web up and down for a 1/4″ chuck or 1/4″ drill bits that could fit the Dremel, and apparently there are a couple of models that advertise to work with it, such as this one:

This 1/4″ chuck is advertised to be compatible with Dremel. The brand name was covered since I don’t want to publicly criticize this specific product/vendor, but you can find plenty of them on online shops.

I had a little of skepticism as nobody seems to be using those.
I did the only logical(?) thing and bought one to test it out.

I hope I don’t have to buy into every scam to prove it’s a scam.

And, well, guess what, it can’t fit the Dremel, the threading is too big.
But at least I could write a blog post about it so you don’t have to buy it and test it yourself.
As far as my research goes, the biggest drill bit you can use with a Dremel is the “Brad point drill bit” (you can find more info on the official Dremel page) which goes up to 1/4″, but that’s it. In this case I was going to drill a hole for a 1/4″ audio jack, which needs to be slightly bigger than the jack itself (about 3/8″) so I guess I’ll have to use another drill.

Boogie Board Sync review

I was looking for a tool to replace all the paper clutter on my desk.

I’ve been looking high and low, and as of December 2018, to my knowledge these are the options if you want to hand-write your notes to an electronic device:

  • a iPad Pro or a Surface tablet, with an Apple Pen or the Surface Pen. They are Not Cheap (around ~1000€). I’ve only tried the Surface, and the input lag is noticeable.
  • a Samsung Android tablet with the S Pen, which, again, is Not Cheap (~700€).
  • another cheaper Android tablet with a regular capacitive pen, but the input lag is huge, and precision is poor.
  • a eInk-based tablet such as the Remarkable, which is Not Cheap (~500-600€) but seems to have very low lag (at least in the ads) and also doubles as an eReader and is capable of partial erasing; it is a very interesting concept, but the price tag led me to search more.
  • a Moleskine Smart Writing System, which uses actual pen and paper, except the paper is proprietary and while Somewhat Cheap (about 1€ for an A4) it is the only system that’ll require money for each page you use (wisely or less wisely).
  • tons of app&camera -based systems, some of which include microwave-erasable notebooks, such as the Rocket Book. These are cheaper (20-50€) but I didn’t like the idea of having to take a picture of the notebook, feeling in the end I’d just use it as, you know, a regular notebook.
  • tons of eWriter systems, which are Very Cheap (as low as 5€), with imperceptible input lag, but no “smart” features that allow exporting your sketches.

That’s where the Boogie Board Sync stood up. It is the only eWriter system with bluetooth capability and also has an affordable price tag (~60€). Due to the lack of reviews on the web, I’m writing my own.

Update 1: The Boogie Board Sync has been discontinued by the manufacturer, so I don’t recommend getting one.
Update 2: A couple more smart writing systems have surfaced, such as the Boogie Board Carbon Copy. I will talk again about those, along with other systems such as the Neo Smartpen, in another post.

The selling feature for me was the integration with Evernote. You can actually sketch something on the board, hit the save button, fire up the app on your mobile phone, let it sync, and have your sketch in Evernote moments after. They’ll all collect in a Evernote notebook of your choice for later reference. Unfortunately, Evernote is not able to recognize the hand-written text inside the sketches, but you can write some keywords (such as a timestamp and title) to make it easier to find it later.

The Boogie Board Sync app could definitely use some improvements. At first I tried to set it up on Windows to have it permanently available, but for some reason I couldn’t get the Evernote syncing to work on my laptop (tested on two Windows10 laptops). I tried to contact Boogie Board support but they never replied (boo!). This is really unprofessional on their part and brought me to the brink of returning the product, but in the end I figured out I could just install the app on my phone instead, which apparently works better. Also, I once had a problem where the app crashed, and upon restarting, it imported again every single sketch from the board, which had to be cleaned out manually; so even the app is not perfect.

The build quality for now seems ok. The board surface might look scratched from time to time, but it looks to be caused by the pen leaving some kind of small trail; if you clean up the screen with a cloth or a finger, you’ll have a perfectly smooth surface again.

The screen is still perfectly smooth after months of use.

On the other hand, it has shown to be vulnerable to hits. I’ve hit the screen probably by dropping my keychain on it, and now I have a couple of spots on the screen where it is much more sensible (for example, they light up if I softly push there with my finger).

A few hits to the screen led to some sensitive points. 

The pen stroke is somewhat thicker similar to the one of a soft felt tip pen, so you’ll have to adapt to writing with larger letters. Also, the screen sensitivity seems to depend on the heat (such as heat from sunlight) and it will grow bigger if the device gets hotter. Overall the vector version of your sketches is good enough to read later, but it is also not failure-proof, as some strokes (sometimes whole letters) will be missing from the end result. If your work involves symbols and numbers rather than words (such as, maths) I guess this could be a bigger issue.

How a note looks on the screen (left), and exported as PDF (right). You can notice some letters are completely missing.

A note on the software: when you delete a sketch, it is actually still accessible by using a USB cable and mounting the board as a USB thumb drive. The sketches are actually stored as vector PDFs on the board. The internal memory is probably enough for ~40k sketches.

The board can also be used as a digital drawing pad, it can left-click the screen by tapping the pen on the board, and right-click by using the button on the pen. It does not have pressure-sensitivity. This was not a relevant use case to me, but it still could be useful to someone.

Overall I’m rather happy with my Boogie Board Sync. I’ve averaged one note per day since when I had it 3 months ago and now I couldn’t go back. It definitely could use some improvements, but the concept is very interesting and as such I hope some competitors make their move with some new models.