Category Archives: Projects

Bench Power Supply Build – Part II

This is the second post on my power supply build – also see part I and the Circuitmaker project page.  The aim of this project is to design and build a linear bench power supply with adjustable current and voltage and up to 2.5A output from 0-30V.

After building and testing the first version of the board I discovered a couple of issues. Most of the basic functionality worked – the voltage control, digital display, transformer tap select, etc. However, the current limiting never worked properly, there were some noise/oscillation issues and a couple of mechanical problems. So, Rev.1.1 was born which has now been tested and seems to be working nicely.

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Temperature Logger

I have finally finished my temperature monitor and logging module, originally designed to monitor beer temperature as it is fermenting (beer, fridge and ambient temperatures). It is an Arduino-based device which measures and displays temperatures from multiple attached temperature probes and logs them to an SD card . This is an old project from last year sometime which has been sitting 95% complete, just waiting on an enclosure and some finishing touches to the code. I posted a separate post about the enclosure design and 3D print, read it here.

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Designing a 3D printed electronics enclosure

This will be a quick post about the design and 3D printing of a custom enclosure for a temperature logger (see full writeup here) – a project which has been sitting on my table 90% finished for about a year now. I always find the enclosure to be the most time consuming and least interesting part of any project. As such an unfortunately high number of them stall at this final stage. 3D printing a custom enclosure is a much more interesting and attractive alternative to my usual approach of attacking a jiffy box with a drill and hacksaw.

The box needs to hold a board roughly 90x50mm, have a slot for an SD card, 3 temperature probe input connectors, a DC jack power input, a 16×2 character LCD and 3 pushbuttons. The design was all done in Autodesk Fusion (see my previous post) and printed on my Printrbot 3D printer (see my previous post). There were several iterations and test prints along the way to check sizing and tolerances and to test out some different designs. The final design can be found on my Autodesk account here.

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Servo Motor Control with Mojo FPGA board

This post is part of my series on building a kinetic sculpture with the Mojo  FPGA development board. (Part1 Part2)

My Mojo development board finally turned up and so I’ve been playing around with it for the last week. This post  is just a quick update of some fist test code to control some servo motors and sweep them back and forth. The end goal of this project is full independent control of multiple servos to create moving sculptures. See this post for an overview of the project.

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Printrbot 3D Printer

After returning from a trip to the maker faire in San Francisco last year I felt like I needed to get involved and buy myself a 3D printer. After some research I settled on the printrbot simple metal. It seems like a solid mid-entry level printer which is easy to get started with and with fairly good support. I went with the kit form with the heated stage option which costs US$749. All up including shipping it ended up costing me about $1100AUD delivered.

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Mojo FPGA development board

This post is part of my series on building a kinetic sculpture with the Mojo  FPGA development board. (Part1 Part2)

Back at uni I did a course on digital logic design (COMP3222 for anyone interested) and really enjoyed it – it was one of my favourite classes. But for some reason I never followed up on it or did any more. I think part of the reason is the relatively large cost and complexity of FPGAs compared with microcontrollers. Anyone can buy an Arduino for a few dollars and get started pretty much immediately. Not so for an FPGA. In order to pick up where I left of at uni I’ve ordered myself a mojo board and plan to start getting back into some FPGA development.

Mojo FPGA dev board
Mojo FPGA dev board

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Bench power supply build – part I

This is the first post on my power supply build. Also see part II and the Circuitmaker project page.

An adjustable bench power supply has been on my list of things to build for quite a while. A linear supply should be relatively simple to design, with the added bonus of being a useful thing to have around. My goals with this project are to design and build a slightly more complex system than I have in the past, to lean to use PCB layout software and to actually get a PCB designed and manufactured. I wanted to design it from scratch, rather than using an adjustable 3 terminal regulator or a controller chip with everything built in – this is supposed to be a learning experience more than anything else.

My requirements are:

  • 0-30V adjustable voltage
  • 0-2A with current limiting.
  • Separate fixed 5V output for powering digital circuits.

Continue reading Bench power supply build – part I

Starting out with CAD – Autodesk Fusion 360

This post is going to cover my first impressions of using Autodesk’s Fusion 360 CAD program from the point of view of someone who is completely new to CAD.  Several months ago I bought myself a 3D printer (a Printrbot Simple – hopefully I’ll do a post on this in the future) partly as an impulse buy, partly because I’ve always been curious about them, and partly as an excuse/reason to learn how to use CAD to design parts.

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Brass etchings – attempt 1

Cleaning out the garage I found/rediscovered some brass sheets which have been sitting there for quite a while, so my first thought was to attempt etching them to make some art. A quick internet search revealed two options, chemical acid etching or electrochemical etching. I decided on the electrochemical route because it seems safer (no nasty acids) and cooler (who doesn’t love a battery with wires running to electrodes in a bath of blue water?). I’ll start with a teaser photo of the results of this first attempt, and then go into some details.

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