Category Archives: Experiment

Promoting STEM Education at the Library

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A few weeks ago, the library consulted me about teaching programming to kids. The Grand Avenue library is already using the CS First With Google and the West Orange library wants to start something similar and asked because of the previous robotics classes I’ve taught for them. While they could also try Google’s CS First, why not experiment with something else? Something a bit more hands on!

The library have always said they wanted to loan out Arduinos but it just can’t happen because of how much other stuff you must include with it before it becomes useful. It is impractical to expect the librarians to count wires and LEDs when an Arduino is loaned out.

So my targets were: low part count, easy to loan and return, full curriculum written.

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Nomad 883 Pro, my first CNC mill

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After getting comfortable with 3D printing, I decided I want to dabble with in-home CNC machines. I decided that I need something powerful enough to cut aluminum, but also precise enough to handle PCBs, and is enclosed so I can keep it in a home environment. I absolutely did not want a machine that’s designed to fit an ordinary router or Dremel. The Nomad 883 by Carbide 3D fit these requirements (link to specs).

I also really wanted to see the machine before I buy. I saw Othermill at RoboGames 2015, and while it seemed nice, it was geared more towards PCB milling. Another choice would’ve been Carvey but it is a Kickstarter that hasn’t started shipping yet. I saw Nomad 883 at the SF Maker Faire 2015, and it really impressed me, perhaps because it was built with all metal structure. The guy at the Nomad booth also hinted that I can cut steel on the next revision of the Nomad 883 (sorry I forgot his name). I picked Nomad 883 because it was more powerful and bigger than Othermill, while smaller than Carvey, and I would get it in around late August.

Long story, but I ended up getting the Nomad 883 Pro version around early November. Keep reading to see more pictures and my first impressions.

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SD Card Bootloader by Backdoor Code Injection

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For various reasons, I decided to try writing a SD card bootloader for my Ultimaker2.

The project is open source and on my GitHub here.

My goal was to install this new bootloader without having physical access to the circuitry. Thus I cannot use a ISP tool and must be done through the bootloader that is already present on the Ultimaker2. The only way to do this is to partition off a portion of application memory region for a secondary bootloader that executes after the original bootloader. But the ATmega2560 has a restriction that prevents anything in the application memory region from modifying the flash memory at all. Overcoming this restriction is what this hack is all about, continue reading if you are interested in learning more.

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