Thursday, February 5, 2009

Accelerometer ADXL330

Today I pulled out the ADXL 330 I had ordered last winter. You can see I am soldering pins to it so I can put it on a breadboard. This I did and ran the Accelerometer Reader from chapter 8. The accelerometer in chapter 8 is a ADXL 320, which is not a 3.3v device and is wired 5v. If I learned 2 things it is 1. don't wire anything to higher voltages than specified, and 2. read the data sheet before wiring.
Another thing that is different is that the ADXL 320 appears to not need the ST pin connected to ground. I dicovered that the ADXL 330 wont work unless the ST is connected to ground. This is after much fussing around, and some wondering if I had overheated it during soldering, etc.

It turns out it worked fine.

Wednesday, April 16, 2008

Arduino + Altoids Tin

Small easy, and awfully unorigional. But, useful and free. Now I can bring my arduino with me in my laptop bag and goof around with it at lunch time at work or wherever. I am thinking I would put a breadboard in another tin of some sort and put a battery pack inside to run any projects I might feel inclined to proto.

I wonder how many altoids have sold just for the tin.

Your basic Altoids tin.

Crudely drill holes to accept 4-40 screws. Line with electrical tape, I liked blue.

Drill holes to allow the use of a sheetmetal nibbler (I got mine at radio shack) The cover interferes a little with the connections but they still connect, and I think I will usually use the arduino with the cover open.

Arduino screwed in with 2 4-40 screws and hex nuts.

Monday, April 7, 2008

Polar Heart Rate Monitor

I have been off my projects for a while. I have been itching to get back onto some projects, one of which as been to make something to take in the signal from my polar fitness heart rate monitor and put out some sort of visual or sound indicator of my heart rate. Maybe a led meter across my head. Something interesting but also data log my heart rate and associate it with some other data like that from a GPS. There are products out there that do this but I already have a lot of the components to do this.

One element that I had just started thinking about is how would I read the signal from the heart rate monitor. Sparkfun just began offering a OEM polar fitness receiver module. How easy does that get? It is $14.95 which is in my price range so I am ordering one. It does require a addtional 32khz crystal.

Another item that caught my interest is they are carrying UV leds. There are warnings about using eye protection. Also interesting is that the stated applications are for insecticide. At $.95 each, a few won't break the bank.

Saturday, February 2, 2008

RFID Parallax Order Snafu

January 5th ish, I decided I needed to order the RFID kit from Parallax. It was in stock and so I did the order for the "kit" which included the reader and 5 RFID tags.

Being very cost conscious I selected the 70cent standard shipping option. After a week of so I started wondering where the RFID kit was, and checked my paypal account and there was an "expired" charge, which means they didn't debit my account. I looked back in my email for a shipping confirmation and after rereading it now, misread their order confirmed email and assumed they had canceled the order because of my selecting the 70cent shipping. I went back to the RFID page on the Parallax site and found the RFID kit out of stock.

This week I was on the verge of ordering the Parallax RFID kit from trossenrobics, thinking that the Parallax order was cancelled. The only thing stopping me was that the shipping would be $10+ and they charge 5% on Paypal orders. I use paypal alot because it is so easy to keep tabs on the account and I don't have to worry about someone stealing my credit card number.

So today I get a box from Parallax with the RFID kit. It has 5 RFID tags, including a key fob, "world tag", disc sticker, card, and a glass RFID tag ("not for implanted use", their words not mine). I just found out it is discontinued on the Parallax site.

I think I am going to skip ahead and try the RFID project.

Sunday, January 20, 2008

Webcam ,Email and Internet Hosting

Started in on web hosting I do (okay lame joke, but I hope you got it!) . Had the lesson in sending email from the Microsoft command line (pg92-93). (Go to START, click RUN, and type CMD then enter to get to the old DOS window) Had fun (no mischief) with sending out emails directly from the command line by telnet to the stmp mail server. The mail server is funny with it's conversational dialog. You telnet in and say Hello (HELO) and it replies "Hello, nice to meet you" when you type QUIT it says bye. I forgot to type HELO when I started in with the MAIL FROM: and it says "Polite people say HELO first". Pretty funny.

Figured out that a subdomain is where you plunk a word with a period in front of the domain. Domain being the web page name. So a sub domain named "subdomain" of would be That was new, though I had seen that before. Just didn't know what sub domain meant.

Mostly simple stuff but lots of it. Neat stuff to poke around with.

Went through my pile of old web cams, and chose a logitech spherical one and got the driver off the logitech site. Downloaded the webcam freeware program fwink. All installed.

All works and here it is:

That was fun!

Wednesday, January 16, 2008

Web Hosting

Okay, I have activated my web hosting. I have a Domain, I think that is what it is??? This is new to me, but it has been fairly easy going, just new, and fun exploring.

Got web hosting with
Used their wiki a bunch to set up SSH and PHP. (really easy)
Used PuttySSH to ??? get onto the hosting directory that I have and do the Chapter 1 stuff on PHP (scripting language to do things on the web site) and the basic tour of command line stuff on the web server. (I am not even sure what to call it;-)

Used the command line text editor nano to write a small php script to put text up when you got to my site ( Not a lot there right now. Just a test message so I could verify that I was in the correct directory with the index.php file.

That all for now.

Saturday, January 12, 2008


I just received the book, "Processing: A Programming Handbook for Visual Designers and Artists" by Casey Reas, Ben Fry, and John Maeda

I got really enthused with Processing from doing the projects in Making Things Talk. (even the Arduino interface is based on Processing) So I bought the book. I bought the MTT book with Pete and he has it now. I found out that I could not do without it so I ordered my own copy, and ordered "Physical Computing: Sensing and Controlling the Physical World with Computers" by Tom Igoe and Dan O'Sullivan. I didn't know it existed until I was on Amazon and started searching around for other books by Tom Igoe. Looking at the Amazon "Search inside this book" feature it looks good. The first section of the book is Basics, so if you are new to electronics it may be worth looking at, the second section is "Advanced Methods" and is most interesting to me as it is a treatment by types "activities" (ie sensing movement, making movement, controlling light and sound etc.) I am hoping it will complement Making Things Talk.

I should get the MTT, and Physical World with Computers book early next week and be back to doing projects. I plan on using the projects as a platform for doing some youtube videos, and try to make them interesting.