my recent reads..

LEAP#223 Fritzing The Boldport Cuttle

Fritzing may be considered the comic sans of EDA tools, but it is often the tinkerer’s first experience of designing and documenting breadboard experiments. Even for the experienced, Fritzing can often be the quickest and easiest route to a simple schematic or design. If you’ve joined the Boldport Club and have a Cuttle microcontroller (project #6), I have a New Year’s gift for you! cuttle_blinky_example_bb

As part of working through the many projects I now have in the LittleArduinoProjects collection, I’ve ended up creating a few custom Fritzing parts. Although Fritzing appears stuck in a perpetual 0.9 beta rut, and the parts designer is a bit of a mystery, it turns out there is enough help and documentation around to make building custom parts a reasonably straight-forward task.

All the parts I’ve created are available in the LEAP#223 Fritzing Parts collection.

Most recently, I made a part for the Boldport Cuttle - which I still maintain is the most beautiful Arduino-compatible board of all time!

The Cuttle is a great project available to Boldport Club members, and if you want to use it for breadboard prototyping then a Fritzing part might help, yes? Since Saar has open sourced the design files, building a part was quite easy. If you just want the part, check it out.

What does a Cuttle really look like? Here’s my build:


Don’t have a cuttle? Just join the Boldport Club and kits are still available for backorder.

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Blogging with Jekyll

I’ve had two blogs kicking around on since around 2004 - tardate and pratalife. I decided to try porting and combining them on GitHub Pages using Jekyll.

This is the result, hosted on GitHub in this repository. If you notice styling glitches on older posts, it is likely due to an imperfect migration that I haven’t cleaned up yet.

I started out using the built-in minima theme, but subsequently switched to largely borrow most of the template as it offers a very good mix of pre-configured features useful for a blog (responsive design, social integration).

My notes on Jekyll investigation and a series of tests are on LittleCodingKata.

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LEAP#222 Stair-step Generator

Once again I'm inspired to go and build a circuit by yet another great tutorial from w2aew.

This circuit generates a stairstep waveform by an ingenious combination of 3 circuit elements:

  • a "high" (265Hz) frequency pulse (555 timer) provides the charge to step-up the output
  • the step pulse feeds an OpAmp pulse integrator/accumulator
  • a low frequency pulse generator (OpAmp oscillator) provides the reset pulse that clears the accumulator and resets the 555

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub.

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LEAP#221 XOR with Resistor-Transistor Logic

Exclusive OR (XOR) operation is true only when the inputs are different.

An XOR may be constructed using combinatorial logic: an OR ANDed with a NAND. But can it be done with even more basic discrete components?

This circuit uses a diode-bridge and a single transistor - quite neat. It does mean however that there is no output buffer, in fact the output is powered from the inputs. I'm using an Arduino to drive the circuit and capture the output plot.

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub.

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