Category Archives: Tool

Voltage Divider Resistor Chooser

This is a special resistor voltage divider calculator. You tell it what is the maximum expected input voltage and the maximum desired output voltage, and a list of all the resistors you already own, and it automatically picks the two resistors you should use. This is useful because it means you don't have to buy a specific resistor for a project, and you don't have to calculate for every single resistor you own. Continue below to use Continue reading

3D Printed Dust Skirt for Nomad 883 Pro

I got a new Nomad 883 Pro and it generates a lot of dust. This is going to be a big problem as I need to cut material that have hazardous fibers. I decided to make a dust skirt (aka vacuum skirt or vacuum shoe or vacuum head) so that a vacuum can suck up dust as the machine cuts. I 3D printed this thing, which is partly PLA plastic, and the skirt is 3D printed TPU (polyurethane) filament. The skirt is two layered and the cuts are made in a interleaved pattern so there’s a better seal. 3D printing makes this project really easy, just clean up the print, superglue, and tap the hole for the screw. The vacuum hose is 1.25 inch diameter and it just shoves right in with a perfect fit.


The CAD files can be downloaded here

3D Printed Micro Match Connector Crimp Tool

I have a project that involves Micro Match connectors. They are similar to IDC connectors, but with a lower profile and a zig-zag pattern.


I had to crimp one connector onto a ribbon cable, my first attempt using a vice failed miserably, instead of the conductors being forced into the teeth properly, the forces instead crushed the connector. Unlike a IDC connector, which is mostly solid plastic, the Micro Match connectors are pretty hollow, thus weaker.


Continue reading to see how I solved this problem.

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Improved “Third Hand” Using Coolant Hose


I don’t really like my “third-hand” tool so I decided to build a better one using flexible ball-jointed coolant spraying pipe hoses. It’s not a totally new idea, SparkFun even sells some of these parts as a kit. But my way is slightly better, and I got the hoses from eBay (look for “Flexible Water Oil Coolant Pipe Hose for Lathe CNC”) instead because SparkFun’s prices were excessively expensive.
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Const. Current Dummy Load, Digital + USB

A simple adjustable constant current dummy load, with digital readout and USB data logging.

Inspired by the dummy load made by Dave from the EEVBlog. I decided I wanted one because I work with a lot of battery powered designs and it’d be nice to have a simple way of testing a battery or power supply in terms of capability, capacity, and heat. It features a 2 line voltage and current reading, a rotary encoder as the user input to adjust the current setting, and USB data logging (plus bootloading). There are more neat features, please watch the video.

Here are some pretty pictures: (Imgur Album)

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AVR Timer Calculator

This is a simple javascript calculator I wrote to help me make timing calculations while working with the timers on AVR microcontrollers. The same calculations applies for all microcontrollers but the prescaler options only contain the ones possible on an AVR microcontroller (the configuration number is indicated in the brackets).

Javascript must be enabled on this page for the calculator to work. Choose what value you want to use as input by pressing the button beside the textbox(es) you want to use as the input. The output will be reflected in the other textboxes.

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Turnigy ESC Programming Card Reverse Engineered

I replicated the functionality of a Turnigy ESC programming card. These programming cards are meant to configure electronic speed controllers (ESC). I always wanted to know how they work. Eventually I purchased one since I need one for my quadrotor helicopter’s ESC, and then I started playing with it.

It should be very simple to adapt the code to any microcontroller.

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USB Descriptor and Request Parser

I wrote a tool to parse some USB data. You put in the data packet into the tool, and it’ll translate it into something you can understand.


The reason why I made this tool is because some USB traffic sniffers do not perform parsing on USB packets (especially the freeware ones), but the binary data can still be obtained. This tool will traverse through the binary data, and translate it into something human-readable, using the official documents from The three types of data this tool can handle are “USB Standard Descriptors”, “USB Standard Requests”, and “USB HID Report Descriptors”.

The “parse USB HID report descriptor” function is the reverse of the (horrible) “HID Descriptor Tool” provided by, and the display format is very similar.

Because USB devices are generally embedded devices, this tool is designed with the C programming language in mind. The output can be imported as an array initializer.

I was frustrated when I couldn’t find a tool for this, so I wrote it in hopes that it will become useful for everybody looking for such a tool.