My Blog

Controlling circuits with the arduino over the internet

Sat, 19 Jan 2008 17:32:01 +1100

Lately I have been experimenting with serial communication with the Arduino. The Arduino in this project is just acting us a dumb device doing what it’s told. It waits in a loop till it can receive two bytes through the serial interface. The first byte is the pin to set, the second byte is an instruction (either on or off.)

I then wrote a small Python script to run over the Common Gateway Interface (CGI). The diagram below shows how I’ve used my computer and the arduino to have circuits able to be turned on or off anywhere over the internet. (see videos below)

PWM & Interrupts

Wed, 26 Dec 2007 18:41:50 +1100

I've been using the same rig I've had set up to play with the features of the arduino now and have been having a bit of fun with Pulse width modulation. This way, I can adjust the brightness of the LED's connected to the arduino.

We Have Power

Wed, 26 Dec 2007 18:36:08 +1100

After finding a few resistors I could use for the LED's, I then hooked up my Arduino to the LED's and wrote a quick program to turn outputs 0-4 on. I was soon angered and puzzled by the two LED's that were blinking, my first thought was loose connectors. After having checked all the connectors, my next thought was that my Arduino might have faulty legs in it (this got me very angry) After having swapped a few LED's around, I was pleasantly surprised to learn about the existence of flashing LED's. I didn't ask for it, the docket didn't show it, but I have a few blinking LED's :D

Sorting, sorting, sorting

Wed, 26 Dec 2007 18:25:33 +1100

Today was a fun, fun day! I know it's hard to tell over the internet, but I'm being sarcastic.

Today, I picked up a 0.25 Wall 300 piece resistor pack (CAT RR-1680, $6.70 from Jaycar) I'm now posting as 12:30AM in the morning after I've been spending the night time sorting through my 300 piece resistor pack (see pictures below.) This is a very slow, long, painful task... that I'm sure a multimeter would have come in handy

First Circuit

Wed, 26 Dec 2007 18:16:18 +1100

I had a bit of a play with my first circuit today. The parts you see below is my Arduino (as shown before in the previous post.) I have also bought standard breadboard wires (note, they are not twisted on the ends) so I could hook it up to a breadbord.

the Breadboard I got was a standard expandable breadboard that you can clip together if you run out of room. This cost $18.50 from Jarcar (I didn't want to spend $41 for the bigger one.) The wires cost me $5.10 in total (for two packets) although, if I ever run out, I'll just buy the big rolls and cut my own. Shown is a few RED and Yellow LED's (costing me $1 for 8.)

My fatal mistake has been the resistors. I bought 0.5W 2K resistors, however I only needed 0.25W 200ohm resistors apparently. This means to see the faintest glow in the LED, I've hooked up 7 of the resistors (pack of 8 cost $0.38) in a series to increase the current to the LED. At least that's what I think I'm doing.

As you can gather after looking at my first circuit below, I've got a really steep learning curve ahead of me, considering I know next to nothing about electronics and electrical components. I am hoping that I will start to pick it up rather quickly though :)

Until I pick up a big pack of resistors, I'm afraid my first circuit (other then the blinking LED on the arduino) is rather limited with 2 LED's because of this flaw of mine. I don't imagine my next post to be until I get a few more LED's to play with.

Got my Arduino

Fri, 23 Nov 2007 18:47:45 +1100

After having ordered my Arduino on my birthday (last wednesday) I was very happy when it came yesterday in the mail. For those of you who don't know me, I live in western Sydney, Australia. I ordered my Arduino over the internet through Little Bird Electronics. The Arduino cost AU$37, but by the time tax and postage costs were factored in, it ended up costing me around about AU$50. After there being a mix up with the post office and being sent to the wrong place, I came home with my Arduino.

The arduino is a microcontroller that is programmed in a C++ like language. For more information on this, please see the arduino's web site.

First impressions when receiving the package was that you don't get much for $50. I've not even opened it yet, but you can see it's not overly big when compared to something like my mobile phone.

 