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My Eagle Library

Posted 2012.08.19 9.06 in Computers/Internet/Technology

In my recent electronics adventures, I’ve had to learn to use Eagle, and in using Eagle, I’ve had to create some parts layouts.

I’ve a handful of parts (packages and symbols) set up. A few are mostly for reference, eg. items I created in order to make the schematics of my Thermostat V3, or the current prototype of my ISEB-6. The symbols are ok, but the packages (board footprints) are not tested and probably not accurate.

Other parts, that I have set up while working on the ISEB-6 Mark-II are more certain, eg. the TQFP-44 footprint for the ATMega1284P, surface mount TMP-36, et cetera. These parts’ footprints are tested and known good.

I’ve left comments in the library to indicate which ones are known to be good and which ones aren’t.

You can download the library by clicking right here: Stephanie’s Eagle Library.

SFCave for Arduino

Posted 2012.08.06 11.48 in Computers/Internet/Technology, Hobbies

Back in the days of Palm Pilot, there was this great little game called SFCave. It was easy to learn, difficult (for me at least) to master, but it was a quick-n-easy thing to pick up and play when you had a minute or two to kill.

I’ve written an Arduino sketch inspired by SFCave, and all you need is an Arduino, a 128×64 OLED from Adafruit, and a single pushbutton.

You are ‘flying’ a ribbon through a cave. You can’t control your speed (it gradually increases) and the cave gradually gets narrower and narrower. Gravity is a factor – push the button to thrust upwards, release it to fall downwards. Try not to crash into the ceiling or floor.

There is no end, the only goal is to see how long you can last / how far you can go. The score is a frame counter, each time the screen advances the score goes up. Check out the action:

You can download the sketch here: ArduinoSFCave.zip

A Github Kind of Day

Posted 2012.01.29 9.09 in Computers/Internet/Technology

For all the years I’ve been dabbling with programming-related projects, I’ve always just put the code on my own website so folks could download it there.

Meanwhile there’s all these other tools and things people have built specifically for sharing code, and I’d kind of ignored them because I had my own easy (for me) way of doing it. The problem with just throwing a zip archive on my site here is that people can download it, but they can’t easily make changes or contribute to its development – in other words, it’s not really collaboratively friendly.

So at long last, I’ve got around to looking into Github, or Git — I don’t even know what it’s supposed to be called, in fact. Whatever it is, I got myself an account and set up not one, but two public repositories.

This first is for my little Chronodot library for the Arduino. This gives you full real-time-clock functionality in your Arduino sketch, and also lets you get the current temperature readings from the Chronodot as well.

The Chronodot library for Arduino is available here.

The second is a high performance i2c LCD driver that was originally created by Matt Falcon. He had shared it via the Adafruit support forums, but it had not been updated for the changes in Arduino’s 1.0 IDE. People were asking for those changes, so I went ahead and modified the library to be 1.0 compatible.

The LiquidTWI library for Arduino is available here.

It Tweets!

Posted 2012.01.09 20.13 in Computers/Internet/Technology

I took a few minutes this evening to geek out a wee bit. My Master Control Project has been sitting there working perfectly, staring me in the face, reminding me that I haven’t messed with it in a few weeks.

It didn’t take long to add a whole new layer of functionality to it, as this one is all software: I got it a Twitter account and programmed it to tweet status reports!

You can see the results first-hand by visiting the MCP’s twitter page.

At the moment it tweets a radiation reading at the bottom of each hour, and a temp / humidity message at the top of the hour. I’ll be adding some more tweet-content as things progress.

Master Control Project

Posted 2011.12.25 9.40 in Computers/Internet/Technology, Hobbies

Last weekend I finally mostly-finished the project I’ve been working on, on and off, for the last several months. My Master Control Project, or MCP*, was designed to be a central controller and information display that would sit on my desk in my livingroom, and give me all sorts of useful information while allowing me to control various things.

The idea grew out of my DIY thermostat project – after getting a taste of what could be done with an Arduino and an ethernet connection, I wanted more!

Plus, the thermostat is located up on a wall and I can’t see it from my desk in the livingroom . I wanted a cool project that I would be able to see all the time!

Unlike previous brief glimpses at this project, this time around I’m going over the whole thing in detail – mainly because it is, as I said, mostly-finished. (It’ll never be fully finished, because I’ll always be adding to it.) The other reason why this is a good time for a write-up, is last weekend was when I rebuilt the whole thing from the ground up, and took the project from ‘beta’ to ‘1.0’.

Thermostat 2.0

So here’s what it does so far:

  • It is a clock, with full day / date and time display.
  • It mirrors the HVAC information from my DIY thermostat.
  • It displays the current temperatures of my two aquariums.
  • It controls the lights of my two aquariums, turning them on and off automatically.
  • It controls my Game of Life wall display, turning that on and off automatically.
  • It displays the amount of background radiation detected by a geiger counter.
  • It displays the number of active connections on my linux server.
  • It displays the current weather conditions for my area.
  • It allows me to directly override the thermostat, aquarium lights, game of life display.

For communication, the MCP is connected via ethernet to my LAN, and also has an XBee wireless module allowing it to communicate with other devices in and around my house (eg. the thermostat).

Pile of Parts

For the most part, the MCP is made with off-the-shelf components. Some components were kits, some came fully assembled, and a few things were ‘homebrewed’. Here’s something of a BOM:

  • Arduino Mega 2560 – the brains of the operation.
  • Arduino Mega Proto Shield – provides connections for I2C (secondary LCD and Chronodot), Serial (XBee), the geiger counter, and the GLCD.
  • Arduino Ethernet Shield – does what it says on the box, this adds 100/10BaseT ethernet, allowing the MCP to receive data and commands from clients on my LAN or out on the internet.
  • Arduino Patch Shield – provides simple plug-in connections using normal Cat-5 cable so you can easily access inputs and outputs some distance from the main unit.
  • KS0108 Display – a monochrome graphic LCD that can dispay text and images.
  • Chronodot – a highly accurate RTC with its own battery backup and an I2C interface.
  • Protoboard GLCD backpack & Wiring Harness – some standard proto-board and ribbon cable, to connect the GLCD and Chronodot back to the Arduino, via the Mega Proto Shield.
  • 20×4 LCD Display – a monochrome LCD character display, for displaying text-only.
  • Adafruit I2C LCD Backpack – an Adafruit kit that lets you use character LCDs using I2C.
  • XBee – a transceiver that lets you communicate with other devices using standard serial protocol, wirelessly at ranges up to hundreds of feet away.
  • Adafruit XBee Adaptor – an Adafruit kit that makes it easy to use a 3.3V XBee module with a 5V Arduino.
  • MightyOhm Geiger Counter – a self-contained geiger counter kit that is easy to interface with an Arduino, and has a fairly sensitive GM tube.
  • Adafruit Perma-Proto Board – an ingenious proto-board from Adafruit, which lets you transfer projects from a breadboard to a soldered, permanent format.
  • Waterproof DS18B20 Temperature sensors – submersible digital temperature sensors, they only require one digital line and you can put more than one sensor on a single line.

The MCP is mostly assembled in layers, each layer is a ‘shield’ using the Arduino lingo. Here are the assembly steps:

The MCP is installed on the upper part of my desk, above the primary display of my computer. This puts it just slightly above eye-level, almost at the centre of my ‘hub of activity’. I spend most of my home-hobby-time at my desk, where my computer and tv are located.

This shot shows the MCP installation, with all its peripherals and cables etc. The modular construction means that if any part fails or needs attention, I can easily access and isolate that part, or replace it if necessary, while leaving the rest intact. And all without desoldering anything!

In terms of software, the whole thing is running with a sketch written in the Arduino IDE. It compiles to a binary of about 47kB in size, and generally uses about 3kB of RAM while it’s running. Prior to last week’s rebuild, I updated the sketch to version 1.0 of the Arduino platform.

The libraries used include:

I’ve added some special characters to the GLCD font definitions, such as the degrees symbol, and used a few graphic symbols as well, such as the fish and snail icons. A couple of the indicators on the GLCD are ‘text’ but I’ve used a graphic to squeeze the text into smaller area than the standard fonts would allow.

For all that I’ve got completed though, there are still some significant aspects that I have yet to include. The most-glaring omission is the lack of any kind of controls on the MCP itself – there are no buttons or switches or anything. I can’t control the Master Control Project, without firing up a terminal and accessing it over a network connection.

On the one hand, this isn’t a huge problem as it needs very little ‘help’ in doing its job – the aquarium lights turn on and off when they should, my Game of Life display is on when I’m around to enjoy it and off when I’m not. And the various data displays show me what I want to see.

However, it would be nice to have some buttons or something, so I could override things quickly and easily. I have some ideas on how to do this, and have already explored some options – touchscreen, rotary control, buttons, etc. Sooner or later, I’ll make a decision and put something into place.

Another obvious step will be a proper front-panel, so that the LCD displays aren’t just haphazardly screwed into the edge of the desk shelves. I’m planning to get a laser-cut acrylic panel made, which I think will look quite snazzy – but I need to finalize my plans on the buttons/controls first.

I’m also toying with the possibility of upgrading the displays. Obviously the GLCD wasn’t enough, hence the added 20×4 character display. Even that feels cramped, so I’m looking at the option of a second 20×4 display… Or maybe there’s some way to replace both of these displays with something all-together bigger – like a little VGA screen.

I have one of those digital photo frames, that I mean to disassemble and see if there’s any way to merge it to an Arduino… but that’s way down the road.

For now, the MCP is ‘done’ and it’s done well enough for me to leave it alone for at least a little while. Should anyone be interested in having a closer look at the ins and outs, I’ve attached a zip file containing the Arduino sketch, the related headers, and a text-file which contains my overview and some wiring and design notes.

Click here to download the MCP zip file.

(* Yes, I’m a fan of the original TRON movie. Not long after I started this project, I couldn’t help calling it the MCP and the name just stuck.)

Chronodot Library Update

Posted 2011.12.01 17.40 in Computers/Internet/Technology

Arduino has just released their 1.0 software update. This is a Big Deal, but it does break some prior content. Changes to the basic libraries and the Wire library have resulted in my simple Chronodot library no longer functioning.

Fortunately it was a quick and simple fix which I’ve attached below.

One of these days I’ll learn how to use Git and do a real repository thing…

Cheers!

Chronodot Library Update

Note – this library is backwards compatible to older Arduino IDEs as well.

Slow Progress

Posted 2011.06.19 20.36 in Computers/Internet/Technology

I’ve been working now and then on my Next Project. It’s slow going but there is progress happening.

This weekend I added a power supply (boring) and a radiation sensor (interesting). The radiation sensor is basically a geiger-muller tube detector. Instead of making audible tick sounds, I modified it to flash a blue LED whenevever it detects ionizing radiation. The counts are tabulated by the MCP’s microcontroller and available as a cumulative counts per day or current counts per minute.

What else can it do?

  • It is a remote display and remote control for my Thermostat.
  • It controls the lights in my aquariums.
  • It monitors the temperature in my aquariums.
  • It controls my Game of Life display.
  • It monitors and displays outdoor weather conditions.
  • It notifies me of activity on my home file server.
  • And now it monitors ionizing radiation.
  • It allows me access to all of this information and all of these controls both in-person and via network.

So I can monitor and control any of this stuff from my iPhone, iPad, at home or at the office, or anywhere.

The main board is an Arduino Mega. It’s using an Ethernet shield and an XBee shield. The radiation sensor is next to the Arduino. The display is a ks0108 glcd. More geeky goodness will be coming next week.