Beginning of this month I entered Seeedstudios give-away, and I won an EL-shield You can find more information about the give-away on the Seeedstudio blog. I received the package this week only 2 weeks after it had been shipped. Not bad for a package that was sent all the way from China to Belgium.
This is the EL-shield:
It is of course compatible with the Arduino Duemilanove/Uno/Mega boards. The shield comes with 4 wires, one end connects to the shield and the other end goes to the EL-wire or EL-tape.
El wire is an electroluminescent wire that glows when you connect it to an AC voltage. The Arduino works with DC voltage so you need an inverter to convert the 5V of the Arduino to 110V AC. The EL shield does not include an inverter, you need to buy it separately. Seeedstudio sells a robust EL inverter that comes with the right connectors to hook up to the shield. The connector with the red and black wire is the input (5V) of the inverter, the connector with the black wires is the output.
To test the shield I plugged it on an Arduino Duemilanove and connected the inverter and some EL wire and EL tape. Seeedstudio has made a wiki page of the shield where you can find a simple sketch to test it. So I uploaded that sketch to the Arduino. Here is a video of the result:
The El shield has 4 connectors to connect EL wire or tape. These connectors can be controlled by writing the pins 4,5,6 and 7 of the Arduino high or low. El wire can not be dimmed with the EL shield, only turned on or of. Dimming EL wire is not so simple you would need to change the frequency/voltage of the inverter. The inverter makes a high pitched sound, this is normal for these high frequency electronics. Another downside of these inverters is that they generate lots of electrical noise. The 5V input of the inverter is fed from a switch mode regulator on the EL shield, it takes it input from the Vin pin or power jack of the Arduino. That way the 5V regulator on the Arduino isn’t overloaded. I have measured the current the inverter draws with 6 meter of EL wire and tape attached to the output and the inverter was drawing 700mA. When you power the Arduino through the USB connector the regulator on the EL shield is not used so the inverter gets 5V directly from USB. I would not recommend connecting lots of EL wire to the shield when you power the Arduino from USB, USB ports can only give 500mA. I hooked up my oscilloscope to the 5V of the Arduino when powering it from USB and the 5V line immediately dropped below 4V with lots of noise. So I strongly recommend to not power the Arduino from USB when using the shield with lots of EL wire. Use a strong battery and connect it to the power jack or Vin pin of the Arduino instead. In the video I used a 2S Lipo battery connected to the power jack using my Lipo to Arduino cable.
The EL shield is the easiest way to control EL wire or tape with an Arduino. The shield is very well made, the high voltage electronics are nicely shielded of with a thick piece of acrylic. When powering the Arduino/EL shield through the power jack the shield generates 5V for the inverter through its own voltage regulator so you don’t need to worry about blowing up your Arduino. The shield and inverter are capable of driving 15 meter of EL wire or tape, that’s a lot :p
I have been working on my hexapod the last couple weeks. So I thought it would be a good idea to add some EL wire to my hexapod. I strapped 3 meters of blue EL wire around it. I programmed it so that I can turn on and of the EL wire with a button on my remote. I’ve made a video of it 😀