Thursday, December 27, 2007

First Ardunio Program

I have finally received my Arduino and have been able to write a few simple programs for it. For my thermostat program I am interested in being able to read several analog sensors (temperature and humidity). I also need to be able to poll specific sensor values from the computer using the serial interface so I can log their values in 5 minute intervals. I don't have all the electronic components yet to build my thermostat so I wanted to write up some test sketches. I based my sketches on a todbot blog entry that I found very useful.

I was originally going to use the C code that todbot wrote to test communication with the Arduino but I soon realized the limitations. What I ended up doing is using "screen" to open a terminal connection to the serial port so I could send and receive data to/from the Arduino. In the future I will have to write a daemon that will run on my linux box that will constantly poll the Arduino for data but thats another story. For now screen will work.

Download serial_tty.pde for the source code.


Using Screen


On my Mac all I had to type to communicate with my Arduino running the above sketch was:


screen /dev/cu.usbserial 9600

To "kill" your screen session you have to type: ctrl+a k


Hope you enjoy. I'm out.

Tuesday, December 18, 2007

Arduino shipped!

I love ordering things in the mail. It's the waiting I don't like. I ordered my Arduino along with a temperature/humidity sensor from Robotshop on Friday afternoon and they shipped it yesterday. Not a bad turn around time at all. According to the Canada Post website it is currently in Quebec somewhere. Now all I have to do is wait for it. I know it's a crazy time of year so we'll see how Canada Post is handling it.

Now all I have to do is find some time to goto Active Electronics and buy a prototyping board and a bunch of misc parts. I can't wait!

I should go do some work... I'm out.

Wednesday, December 12, 2007

Thermostat project (take 2)

Yes I am still on the thermostat kick. I just got my new humidifier installed today which is probably why I am still looking at my thermostat project. After some consideration I have decided that I'm going to scrap the whole gumstix idea. The reason I'm doing this is simply because I don't need that much computing power bolted to my wall. I've decided that the thermostat itself should be an Arduino using I2C to talk to a Temperature and Humidity sensor. Then I would have to design the circuit that would turn the furnace on and off. I have found some good documentation of how a regular thermostat works so it shouldn't be much of an issue getting that going. The Arduino would control the furnace and air conditioner, fan and humidifier. One added feature (the whole point of the project) would be to use the USB interface on the Arduino to connect to a LAMP server that would log all temperature and humidity levels and send commands to the Arduino. I just have to figure out how far the USB cable can actually be before I pursue this option any further. I may have to use some other communication methods.

I'm tired... out.

Monday, December 10, 2007

Thermostat project

It's that time of year again. Winter has hit full force here. I've been on an Arduino kick lately and came up with an idea for a project to battle the cold weather. A thermostat connected to your home network!! Why would you want to do that you ask? The answer is simple, I want to be able to control the temperature of my house from anywhere! If security is a concern then you could limit control to your local network (but that's another discussion).

Hardware:
First you would start with a gumstix connex 200xm along with a rs232 expansion board and an ethernet expansion board with a microSD interface for more storage. You could also go WiFi if you so desire. You will also need a temperature and humidity sensor with a serial interface.

Software:
The software system would be as simple as running a LAMP (Linux, Apache, Mysql, PHP) server. Of course I would have to develop some software to get the temperature readings from from the sensors and for controlling the furnace. The Mysql server would be used to log temperature/humidity levels and when the furnace and AC are firing. The Apache server would allow you to control the furnace remotely. You could also automate the temperature in your house. The possibilities are endless :)

The major problem would be to somehow control the furnace/AC. I have to figure out exactly how a furnace works yet before I can design that circuit. I might have to re-think the hardware required and add a robostix to the mix. We'll see.

In the end you would have a completely automated thermostat for your house! Perhaps you could also add X10 capabilities. Very cool.

Until next time. I'm out.

Monday, December 3, 2007

Audio Projects

My last post had to do with making a robot that made parts for itself. It's time to shift gears and talk about making audio components. I've always wanted to put together a guitar amplifier from scratch but I've never been able to find a really good explanation on how to do it until I found this website. It's a fairly comprehensive look at how to build a JCM800 head. If you've ever been interested in putting together your own tube amplifier it's a great place to start. He has a lot of great ideas and insightful things to say about building tube amps.

What about effects? I found a really nice website online with a bunch of information on building your own effect pedals. It's called Super-Freq. He has a bunch of schematics and circuit board layouts on there. Check it out for yourself. I'm sure there are other websites out there with effect pedal layouts. Let me know if you find any!

While I was writing this post I also stumbled across Geofex website. They also have a bunch of information and links for good places to start looking for information on building tube amplifiers and effects.

That's it for now. I'm out.

Friday, November 30, 2007

Reprap part 2

I'm back... with the second post about the Reprap robot. I did warn you that this blog would be full of geeky things didn't I? They actually renamed the Reprap robot to Repstrap. You can check out part 2 here.

It truly is an amazing idea. The mechanics and electronics that go behind these robots have always baffled me. Even now when you watch the video it looks really complicated. At work I take care of and administer something very similar to this robot called a tape silo (IBM 3584). It operates on the same principle as the Repstrap robot does. There is a robot arm that moves along an X and Y axis to move tapes around. The difference is the Repstrap robot is a 3 axis robot. When you look at the tape silo the mechanics behind it are actually quite simple. A rail for the X axis and a screw for the Y axis.

The more research I do on these type of robots the more I realize what a simple concept they really are. Whats really cool is you can use the same concept as the Repstrap robot to make a 3 axis milling machine or CNC Router. I might in fact build one of these things one day. I just need to somehow find some more time. Right now I have too many other projects on the go. Don't worry, I'll talk about them in my blog sometime in the future.

That's enough for now. I'm out.

Tuesday, November 27, 2007

Standard boring post... with a twist!

I've been waiting for something interesting to post but have found out that I don't really have anything interesting to really say. I've been reading Ali's blog and I have to say that I'm rolling on the floor laughing every time he posts something new. Ali's blog is great for people who know the guy. I'm not sure how people who don't know him would react to reading it. But, I'm digressing. My point is that Ali always has something to say. I on the other hand do not. Judging by this post I have probably bored all one of you to tears sooo from now on I'm going to post cool things.

Cool things (and probably geeky) things like Making a Reprap Robot. What is a Reprap robot you ask? Simply put it is a self-replicating rapid-prototyping robot! Okay maybe not so self-replicating but the whole point of the robot is able to make it's own parts. Cool huh? Go check it out. I'm really thinking about building one. Oh so many projects... so little time.

Friday, November 2, 2007

I dont know

Yeah, I dont know what to say. This is my first post..... SO yeah.. take that.

Peace to your hommies.

Twittering from the linux command line using curl

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