Sunday, March 26, 2017

Recycling CD cases

For years I ditched CD cases, but, interestingly, I eventually found some use for them in the last two days. I start regretting the many I should have kept...

CD case as material for an engraved logo. I really did not expect it to produce such a nice result.
Light coming from aside gets scattered by the scratches (I should try adding SMT leds sideways).
The trick was to move quickly, to avoid melting the polycarbonate.

And used as for the bottom protection of a Smoothieboard (which drives the aforementioned CNC mill)
CD cases do break too easily, but they are very convenient as they leave the signal names clearly readable.

Tuesday, March 14, 2017

Arducam too unstable to be useful

The costly Arducam Mini 5Mpixel camera module.
Warning, read before you buy, I do not recommend it!
After weeks of fighting I came to the conclusion that the Arducam ecosystem is useless, and even counter-productive to me -- while its original goal was obviously the opposite.

These camera are sold to provide pictures to Arduinos and other microcontrollers. The Arduino does not have enough memory, so these boards embeds enough processing power (FPGA?) and on-board memory to bufferize it and allow for serialized data to be stored and then transferred on demand. This way, the Arduino can store on an SD, or send it over GSM as I needed.

Now, the hardware may be nice and promising, but the software is really bad in my opinion.

This is strange to me as the Arducam is a wellknown project, and it is costly: I paid 43€ on watterott for example!

But it did not help me work faster, on the contrary. I really had all kinds of problems with the software, trying to interface both on a Uno or on a Mega.

The examples are half-baked, the API code source and the entire library is bloated with tens of variants of boards (28MB zipped just for the Arduinos!). Even the links to source code examples on some product page are broken. All in all, I consider that this somehow expensive camera is barely usable as it produces way too often invalid JPEG streams.

Monday, March 6, 2017

Cheap plastic boxes and enclosures that are just plain good

Below is is a collection of many of the sizes I found on Banggood, mostly to give me a real life feel of the stuff and to have them ready for future projects. I never have the proper box and I often revert to 3D-printing. But they do not look always as neat or they are not as weatherproof as a regular box for some outdoor projects... and it takes a long time to print in any case.

Probably not comprehensive, but a first-hand evaluation of many of the boxes found on Bangood.

Universal mini micro crimping tool

"Serious" crimping tools cost a lot, and are often outrageously expensive.

I still ended up buying one at "only" ~$50, and it improve both my productivity and the reliability of my connections a lot. Specifically, and foremost if you just want to buy only one like I did initially, I highly recommend the PA-09 (the one below), which is suited for all Molex & JST crimps that I use as a DIY/semi pro guy.

I liked this Japanese "Engineer" brand so much that I then happily bought the larger PA-20 (I do not use them often), in addition to a neat wire stripping tool for small diameters (which I use all the time, even though I have to admit that cheap ones probably do the job as well).

You may want to check the many educated comments people left on my G+ post regarding these. You can check also Andreas Spiess review and comparison with a no name Chinese crimping plier, which I found out later, but which is awesome as always.

Not cheap but worth it as soon as you have more than one crimp job to do!

A very short (<1min) promotional video,
which highlight clearly how it works.

Cheap caps for multimeter probes

I lent my multimeter equipped with super pointy probes, which tiny caps I had lost long ago. I got it back with these instead. Smart, efficient and much faster than something 3D printed :)

KISS: protect your pointy probes with pen caps!

How to store dupont cables in a box

Just to share, I eventually found a nice way to store DuPont wire cables efficiently (aka jump wires, or breadboard jumper cables).

I re-shaped the movable separators in a super low cost, floppy box I bought on the internet.

I should have taken a picture of the former mess. The cables would never stay in place before I had a chance to close the drawer!

One definitive way to store prototyping cables efficiently in a box (female-female, male-female, male-male).
These cables are also named DuPont or Jump wires, to use with
 "breaboards" (e.g. the small black one here).