By Bajdi on December 26, 2011
Now that I have 2 Arduinos I need something to power them. Easiest is to power the Arduino with the USB cable that you also use to upload a sketch. If you’re going to use it without a pc you will need another solution. One solution is to buy connectors that fit on 9V 6LR61 batteries on one side and have a 2.1mm plug on the other.

To power the Arduino from a wall socket I bought an adapter. More information on what kind of adapter you need can be found on the Arduino website. At the local electronics shop I found a regulated universal voltage adapter.

It has a switch to set the voltage from 1,5 to 12V and comes with a bunch of different connectors that can be easily changed, the Arduino needs a 2.1mm plug. At 9V it can output 1100mA and at 12V 1000mA. More then enough juice to power an Arduino and some leds and sensors.
The uber cheap solution to power your Arduino is to simply buy an USB charger. One of these cheap Chinese made adapters came with my made in China Android smartphone. These things are really cheap, but not the most reliable. The one that originally came with my smartphone died after a couple of days. I ordered a couple of new ones on ebay, you can easily find these for a couple of euro’s shipping included. The ones I have give 5,4V and can deliver 500mA. That should be enough to power an Arduino.

USB adapter
For things that need a lot of amps like for example a stepper motor you need to provide a separate power supply direct to the motor or driver board. Since the I/O pins of an Arduino Uno can only switch 40mA. Luckily I still have a big old lab power supply, cost me quite a bit of money a long time ago and I haven’t used it in years. The voltage can be regulated between 3 and 15V and it can provide 25A. It’s an excellent device to release smoke from electronic components 🙂 I do my best to not use this function to often.

EP925 power supply
Posted in Buying parts |
By Bajdi on December 26, 2011
After spending some time on the Arduino forum I found a link to the Arduino-direct webshop. It’s a Chinese webshop, and that means they have very competitive prices. Of course shipping and potential import duty and VAT makes it less interesting. I ordered a couple of hundred dollars of parts and had it shipped over by DHL. The package was delivered in less then a week, and that was just before Christmas. The customs people were probably to busy to have a look at it so I was very lucky and didn’t need to pay anything. Thank you DHL 🙂
I bought an Arduino Uno, Mega 2560, ethernet card, breadboard, lots of cables, little stepper motor, IR remote, a whole bunch of sensors and electronic components. This should be sufficient to keep me busy the next couple of weeks.

Posted in Buying parts |
By Bajdi on December 26, 2011
Rant:
Installing Arduino on Gentoo is a b*tch. For Arduino you need the avr gcc toolchain, this you can install through a portage overlay. But because of some bugs in avr gcc this won’t compile correct code for the Mega 2560. After googling for hours and reading dozens of forum and blog posts I got nowhere. I thought about installing a fresh gcc in a chroot environment but this seemed pretty complex. Luckily I found some interesting threads on the avr freaks forum. Someone has made .deb packages of the avr gcc toolchain, you can download them here. To install them you just untar them and extract the files to your hard drive. Then you only need to add the path so you can compile stuff with avr gcc. That was really easy 🙂
Arduino itself I just downloaded from the official site, I’m not using the latest 1.0 version. I quickly found out that some libraries don’t work with the 1.0 release so I stuck to the older 0023 version.
Posted in Gentoo |