May 26

Trash Can Repair

I have a fancy dual-bin automated electric trash can.
I almost like it (well, if it would also be Alexa-controlled… sounds like a new project idea…)
Anyways, it has 2 bins – for trash and for recycle.
And it has a fancy trash bag holder. Which has an interesting design but way too flimsy and does not stay in place.
So I decided to reinforce it.
Here is my design:

And here is the cutout:
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Mar 07

Is there a chance for fast laser engraving?

Laser engraving is pretty cool.
However, it has obstacles.
The biggest obstacle is engineering stubbornness.
Let’s take a look how getting mentally stuck inside the box holds us back.

Laser engraving with common GRBL controller is known to be sloooow.

Some folks claim that STM32 controllers are faster.
So I have got one of those and did a bench test.

Here is the board.


Spoiler: result was unexpected, but you can probably guess that by my bitterness in the introduction.

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Jan 31

Program STM32 via USB

STM32 is an awesome alternative to Arduino board. Unlike 328P, it has native (fast) USB support. It is cheaper than 32U4. And it faster, 32 bit and has 10x more RAM!


Also, unlike Atmel, counterfeits wannabes are clearly identifiable (look at the microcontroller on your board. If it is CH32 – throw it into a trash can. STM32 and CKS32 are good)

It is easy to make it work – just follow the instructions:

STM32 Arduino Instructions

(you can also use ST-Link V2 and connect to the board via 4 wires. I have found this approach very reliable. You can both flash firmware and upload sketches from Arduino IDE. I set both boot header switches to “1″ when I do it. But programming via USB is more convenient, right?)

Ok, so you follow the instructions from Windows 10 PC and try to program your board via the USB and it cannot find the DFU.
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