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Two Screens: Still Better Than One

Posted 2011.06.21 23.11 in Computers/Internet/Technology by Stephanie

So with all the features and functions I’m adding to my Master Control Panel, one screen just wasn’t enough any more to display all the data it’s collecting.

I’ve used standard character LCD screens before, on my Thermostat and the randomizer, so I figured I could just add one to the MCP as a secondary display. Then I thought, why limit myself to a measly two rows of 16 characters?

The 20×4 screen sounded like a way better idea… I just didn’t realize it was going to be so physically big!

It feels bigger than the primary display. Now I’m all unsure if I like it or not. I want more display resolution, to display more data. I don’t know whether to stick with two displays, or these two displays, or try different displays…

Decisions decisions.

Meanwhile, the radiation sensor is telling me that at the current rate cosmic and gamma rays are passing through my livingroom, I can expect to develop superpowers in approximately never.

Slow Progress

Posted 2011.06.19 20.36 in Computers/Internet/Technology by Stephanie

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.

Tinkerers’ Rules

Posted 2011.05.15 10.34 in Computers/Internet/Technology by Stephanie

Brought to us by Wondermark.com

Quoth the Maker: If you can’t open it, you don’t own it.

Back in Business!

Posted 2011.04.18 21.25 in Computers/Internet/Technology by Stephanie

The parts I needed arrived today, so it was just a matter of asembling a new ‘motherboard’ then wiring it into the thermostat enclosure.

The parts were mainly the circuit board and the ATMega328p chip, along with the sundry support electrics. To be honest, I’m using the SparkFun Serial LCD kit — for $25 it’s almost a complete self-contained mini-Arduino that piggybacks onto the back of a 16×2 LCD display. And it even includes the LCD!

If I knew how to use Eagle and if I had more time, I’d have made my own PCB design. I still might do that as I now have more LCD screens than boards to slap on the back of them. The SparkFun Serial LCD isn’t perfect, but it’s actually quite close.

So my DIY networked Thermostat is back up and running with a shiney new brain, my house is once again comfortable, I’m out of the stone age and back in the World of Tomorrow, and I’m a happy camper.

And just for kicks, I took the old dead board and tossed it in the dishwasher, ran a load on ‘heavy-duty pots-n-pans’ mode, and the darn thing is actually working again. Go figure! I won’t trust it in mission-critical use, but I can certainly use it for prototyping or making stuff that’s not, you know, directly wired into my friggin home.

Yep, once again all is right with the world.

Chronodot Library for Arduino

Posted 2011.04.09 22.44 in Computers/Internet/Technology by Stephanie

When I was working on my Thermostat project, I came across the Chronodot RTC (real time clock) and decided it would be the perfect choice. Not just because it’s incredibly accurate, but because it provided both time and temperature readings in a single package. I could have used another RTC such as the DS1307 which is less expensive, but then I would have had to use something else for reading the temperature.

The only thing about using the Chronodot to get temperature readings was that there wasn’t an Arduino library that could get me that information. The Chronodot communicates using the i2c protocol, and as I hadn’t used it before I was hoping to find some examples and a usable library. Fortunately it’s compatible with the DS1307, but of course that library has no reference to temperature as the ‘1307 doesn’t read the temp.

So using the ‘1307 library as a starting point, I expanded it by adding two new readings to it: temperature, in both farenheit and celcius.

The library includes an example sketch. If you’re familiar with using the DS1307 with an Arduino then the Chronodot library will be an easy drop-in replacement. The time features are unchanged, I’ve just added the two temperature readings so they’re available within your sketch.

Click here to download the library: Chronodot_Library.zip

Thermostataliciousness

Posted 2010.12.23 9.43 in Computers/Internet/Technology by Stephanie

Last night I got the bluetooth wireless module hooked up and tested it out. It works! My prototype thermostat can be wirelessly queried and controlled!

The bluetooth module is the little red thing at the left edge of the breadboard. It talks serial to the microcontroller and talks wireless to the computer. As far as the computer is concerned, it’s just a standard tty serial port. It’s fairly seamless!

In the above screenshot you can see some debugging info that comes over every 15 seconds, plus I sent the ‘run program’ command (rp) and the DIY Thermostat responded accordingly!

Geeky techy stuff below the fold.

Read more »

The Humble Thermostat

Posted 2010.12.12 12.46 in Computers/Internet/Technology by Stephanie

I’m a big fan of the Thermostat. They’re clever, and all they want is for us to be comfortable.

Even the simplest mechanical ones are really little robots, whos only goal in life is to keep you comfortable. You tell them what you want the temperature to be, and they dutifully turn the furnace (or A/C) on and off all day and night so that your house remains in your comfort-zone.

The programmable ones of course take this to the next level – with a programmable, you don’t even have to tell the thermostat what your desired temperature is. Or rather, you tell it once, what temperatures you prefer throughout the day and the week, and from that point on, it keeps you comfortable. It’s like magic.

What else in the home works so hard to keep us comfortable, yet asks for nothing in return? The only thing that I can think of that comes close, is a chair or a sofa.

Despite all this, however, I’ve been starting to want more, from my thermostat…

The first seeds were planted several years ago. I saw a programmable thermostat that came with two remote controls. It was outrageously expensive, but there is an undeniable appeal to the thought of being able to crank up the heat without getting out of bed, on a cold winter night. The cost, however, was beyond my means at the time. And by the time I could afford it, that unit was no longer available.

Then last year, the local utility company sent out offers to get a thermostat that you could program over the internet. It sounded like a good idea, but at the time, I did not persue it. They sent the offer again this  year however, so I did investigate.

Their unit is a normal programmable thermostat, that has an RF receiver in it – basically a numeric pager unit. This allows one-way communication, so you can send commands to the unit but not retrieve any information. It’s free, but you have to give up some control: they’ll give it to you, if you agree to let them turn off your air conditioner if the demands on the power grid are too high.

Still, it looked hackable so I filled out the application. They never got back to me; I figure its because I use so little power that they’d never recoup their costs of giving it to me.

Finally, last week I spotted a thermostat at Canadian Tire that came with a remote control. It wasn’t too costly so I grabbed it, with the intent of hacking it. It was a Noma model, which I think is CT’s house brand? Whatever. Let’s look inside!

Aside from the generally poor construction, here’s some things to note: The unit uses RF communications, at the 915MHz band. Comms are one way only, with data going from the remote to the base. This allows the base to display the temperature info from wherever the remote is, but the remote cannot display the temperature, mode, current function, or anything else, from the base. The remote allows you to override the base to a maximum of +/- 6 degF (3degC). Finally, both the remote and the base use a cheap thermistor to determine temperature.

So, it’s not perfect. The one-way comms is a real limitation I think. An additional pisser is that you can easily hack into the comms on the base (since the RF is on a daugher board) but on the remote, it would be much harder as none of the communication lines are accessable (damn those black blobs.) So anything you hack in, is easiest to add at the base, meaning you lose the remote aspect – or have to roll your own remote anyways.

Indeed, when I tried to use it as it was intended, it didn’t really work well anyways. It’s a novelty, but not really a very good thermostat. Verdict: Fail.

So what is it that I really want?

Putting together all the various ideas, I want a thermostat that is programmable and runs fine as a stand-alone unit. I also want it to be able to be accessable via remote control, but with two-way communications, so that a remote unit can at least display everything that the base unit can display, plus the remote should be able to alter the temp, maybe switch modes to hold / run, that sort of thing. Finally, it would be really nifty if it could be wired into my home network, so I could access the data and control through my computer, laptop, iPhone, etc.

The solution, then, is to build my own thermostat, from scratch!

Stay tuned, this story is not over.