sundh.com » electronics

Small Ehternet access just got smaller

Ellen — Thu, 12 Jan 2012 21:08:37 +0000

The Arduino Ethernet shield has been around for some time now. It’s a great solution for cutting out the middle man of the computer when check things online from the Arduino. In order to build smaller cases I stumbled upon EtherTen from Freetronics. It’s a fully Arduino-compatible board that runs Arduino code AND connects to internet with Ethernet.

Lets make a list of the pros:
- Smaller than Arduino board with Ethernet shield on top
- Runs Arduino Ethernet library
- Power of Ethernet, no power supply needed (!!!!)
- Micro SD card holder
- And sexy round corners (rounder than the Ethernet Shield)
- Neat mini USB socket

When it arrived I simply ran the TwitterClient file by Tom Igoe in Ethernet examples of the Arduino IDE and it was up and running. To call my custom php file was a bit harder though. Example code to be posted on my Arduino Circuit Blog shortly.

My Arduino circuit blog

Ellen — Mon, 31 Oct 2011 10:45:36 +0000

Whenever I make a circuit I try to document it and take photos. With the Fritzing software it gets even better. To share code and circuits I gathered my Arduino circuits on this new blog: Ellen Sundh’s Arduino Circuit Blog

Geek Girl Arduino Workshop

Ellen — Wed, 12 Oct 2011 10:15:14 +0000

During the Arduino Workshop with Geek Girls Meetup we went through a number of sensors. A full list will be posted here soon. Here are some images from the workshop:

The dirty robot

Ellen — Sat, 01 Oct 2011 16:55:25 +0000

Some robots only reacts on very dirty words. It’s a struggle but what could you do. This robot reacts on Swedish dirty words (genitals and poo related words).

Turn on lamp with iPhone 0.3

Ellen — Tue, 24 May 2011 20:58:14 +0000

My first test of controlling the Arduino outputs from an iPhone app. I use the firmware for Arduino and a Processing script checking if the light is on or off and sending the info to the Arduino board and the lamp. Code will soon see the light here.

Flex sensor meets Wave Shield 1.0

Ellen — Sun, 15 May 2011 13:15:06 +0000

I soldered together a Wave Shield 1.0 to be fit on the Arudino. There is a version 1.1 so if you follow the solering instructions make sure you look at the right one. Version 1.1 differs in components and placement of them. The Wave Shield can play Wave files stored on the SD card. The SD card needs to be in FAT16 format. The Wave files must be saved in mono, 22KHz, 16-bit. Audacity is a very nifty and free audio software for Mac, Linux and Windows to convert and record sounds in mono.

There are several libraries build to support the shield. The example below is using the older AF_Wave library while there is a newer library called WaveHC.

The following code prints out the sensor value in Serial Monitor and plays a sound if the value of the flex sensor is less than 600:

void loop() { 

   flexSensor = analogRead(0); 

   Serial.println(flexSensor);

   if(flexSensor < 600) {

      playSound("ERROR.WAV");

   }  

   delay(1000);

}

You can view the enitre Arudino source code here

Get Processing and Arduino to talk

Ellen — Fri, 13 May 2011 14:58:48 +0000

I want to use the muscles of Processing to get my Arduino do really cool stuff. In order to do this I want both of the softwares to talk to each other. It proves to be a bumpy road depending on versions of you Arduino board and processing. My set up is a Mac OS X 10.6.7, Arduino board Duemilanove with Atmega328. If you already have the Arduino and Processing software installed do the following:

1. Download the Processing library, unzip it.
2. Put the folder “arduino” inside a folder that you call “libraries” within your Processing Sketchbook folder.
3. Connect your Arduino board and open up the Arduino software, upload the sketch StandardFirmata from Examples/Firmata. Close Arduino software.
4. Add a LED diod to pins Ground and 13 on the Arduino board and run the following code in Processing:

import processing.serial.*;
import cc.arduino.*;
Arduino arduino;

int ledPin = 13;
void setup()

{

//println(Arduino.list());

arduino = new Arduino(this, Arduino.list()[0], 57600);

arduino.pinMode(ledPin, Arduino.OUTPUT);

}
void draw()

{

arduino.digitalWrite(ledPin, Arduino.HIGH);

delay(1000);

arduino.digitalWrite(ledPin, Arduino.LOW);

delay(1000);

}

Whoohooo!!!! You should now see your LED blinking on and off.

Troubleshooting

Mismatch of RXTX libraries
When running your Processing sketch the following error can occur:

WARNING:  RXTX Version mismatch

Jar version            = RXTX-2.2pre1

native lib Version  = RXTX-2.2pre2

1. Download the latest RXTX library from http://rxtx.qbang.org/

2. Find the files librxtxSerial.jnilib and RXTXcomm.jar in the unzipped folder structure: MACOSX_IDE/ForPackageMaker/Install/Java/Extensions

3. Copy the 2 files into the folder: Harddrive/Library/Java/Extensions

4. Close down Processing and right-click on the application in the “Applications”-folder and select “Show Package Contents”. Go to folder “Contents/Resources/Java/modes/java/libraries/serial/library”. Replace the old RXTXcomm.jar with the new file in this folder.

5. Replace the file librxtxSerial.jnilib with the new file in the “macosx” folder “Contents/Resources/Java/modes/java/libraries/serial/library/macosx”.

6. In order for this to work properly also follow these steps taken from here:

1. Under Finder click on the “Go” Menu
2. Select “Go to Folder…”
3. Type “/var/”
4. Finder will open var folder.
5. Right click on folder named “lock” and select “Get info”
6. Open drop arrow titled “Sharing & Permissions”
7. I set all privileges to: “Read & Write”
8. Close Info
9. Go to the Var folder on the finder and open the “spool” folder
10. Right click on folder named “uucp” and select “Get info”
11. Open drop arrow titled “Sharing & Permissions”
12. I set all privileges to: “Read & Write”
13. Close Info
14. DONE

7. Restart your computer and Processing. The output you should see is:

Stable Library

=========================================

Native lib Version = RXTX-2.1-7

Java lib Version   = RXTX-2.1-7

RXTX Warning
If you got this warning. Make sure you went trough the entire step 6 in the previous block and that the user you are logged in as have the permissions to read & write on these files.

RXTX Warning:  Removing stale lock file. /var/spool/lock/LK.255.000.134

Getting values from a flex sensor

Ellen — Thu, 05 May 2011 13:08:37 +0000

First step in my project:

Depressed shoe shelf in action

Ellen — Tue, 25 May 2010 11:09:04 +0000

Read more about the process on making The depressed shoe shelf.

Your pulse as an input

Ellen — Mon, 03 May 2010 11:26:10 +0000

Maria Paz is exploring the field of mood inputs by using your pulse as an input to control your environment. The sensor is sending out light that is reflected in the finger and back to the light sensitive sensor. As blood is pumping and flowing in the finger the amount of light received back alters. The output gives you the pulse of your body. Follow her progress in working on her final project Mood Tunnel on http://themoodtunnel.posterous.com/

Nintendo Wii introduced the Vitality sensor a few months ago, working as an input to measure your health and can be used in games.

LEDs translating human pulse from Maria Paz on Vimeo.