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.

PCB milling: how to verifiy the accuracy of routed traces

Inspecting an Eagle PCB milled board

Here is how I verify that my pcbgcode settings are good, and more precisely, how accurate the "etched" traces are, in relation to the depth of cut. The latter is not easy to set when using V-shaped mill bits, since the deeper, the wider the traces. The one below, between two pads is only 0.01 inch, i.e. 10 mils, and it was properly milled.

The trick was to overlay the live image from an USB microscope over the Eagle board design, scaling the windows appropriately. I applied 50% transparency to the webcam window (I am using ''cheese'' here), which is trivial with Kubuntu / linux. The microscope is an Andonstar, a great & cheap tool, for which I wrote a micro-review here.

By the way, I will no more use these "titanium" coated V mill bits, as they produce rough edges compared to the cheaper ones I bought earlier on ebay. This board is just ugly. Well, the PCB copper clad is also a super cheap one (I bought a lot "50Pcs 70 x 100 x 1.5mm FR-4 Single Side Copper Clad PCB Laminate Board" for $37 on ebay: I could not expect much but they are NOT FR4 but old style bakelite, not fiber glass! Much more fragile, not really worth).

Also my holes are slightly off-center, but not bad enough to be fatal here. Cheap 0.8 mm drills?

Easily count tiny items (200 PCB vias here)

One way to check the number of items I just bought on ebay.

How can I check that there are really 200 vias in these bags?

I bought packs of 200 tiny rivets for vias (or check aliexpress for cheaper and choice). Since I am making my PCB on a mill and I often only use only single-sided PCB copper clads, it gets tricky to solder the headers from below. This is very annoying for headers and Arduino shields for example, as they protrude from below also...

I was somehow able to do it but a proper way is to insert so called PCB "through hole rivets" first. This way, the headers can be conveniently soldered from the top, once they are themselves inserted in the rivets (I wrote about it here).

But such rivets are not cheap (I got 200 of them for $20 on ebay!). I felt I had been cheated on when seeing the small volume it represented. Really 200?