After my two children grow a little, I have some spare time to play with RaspberryPi. I have bought a Raspberry Pi 2 Model B, a very neat and compact machine with 1GB of RAM, and a quad-core ARM chip on it.
Hardware disclaimer: specification are a lie…sometimes
I was skeptical because RaspberryPi was based on a SoC architecture, anyway its ARM 900Mhz quadocore processor wins over me. There are some caveats: for instance the Ethernet port bandwidth is shared with the USB port; graphic capabilities are fair (like XBox1) anyway.
Also using an SD Card as hard disk is a smart choice for a classroom pc, but the cost at Gigabyte and performance are horrible. Even worst, SD Card tend to broke soon if you do not employ some smart setup
Said that, I paid 3000€ in 2000 for a Pismo PowerBook with 64MB of RAM, composite video and a 400Mhz PowerPc. And today for 100€ you can bring home two RaspberryPi for a total of 8 core, XBox1-like graphic capabilities, dual display and 2GB of RAM: not bad!
Hardware disclaimer 2: do not compare with micro controllers, please
RaspberryPI vs Arduino comparison is a huge mistake. Arduino is a neat microcontroller with huge support behind. Arduino is an open source hardware project, whereas some part ofr RaspberryPI are propietary. Raspberry has less I/O pins then Ardunino, but can be programmed with more ease. So they share similarities, but in opposite directions.
A Linux Box very well configured
RaspberryPI 2 is a Quad Core ARM with the following software on board:
- Customized Debian Kernel (no ubuntuzed, yeah)
- Python 2 / Python 3
- Mathematica (for no-profit only but a nice shot for studing)
So you can program I/O pins (GPIO) easily in python or even in Mathematica.
We have found also a nice .NET example.
Erlang 17 can be compiled in less then an hour (use make -j 4 for better performance).
Can Drain power from other usb devices
The RaspberryPi can be powered by USB if you regret adding USB disks and/or other stuff which drain power (a keyboard and a mouse are ok).
You can easily break your RaspberryPi board if you provide more power:
For example: 4xAA rechargeable batteries would provide 4.8v on a full charge. 4.8v would technically be just within the range of tolerance for the Raspberry Pi, but the system would quickly become unstable as the batteries lost their full charge. Conversely, using 4xAA Alkaline (non-rechargeable) batteries will result in 6v. 6v is outside the acceptable tolerance range and would potentially damage or, in the worst-case scenario, destroy your Raspberry Pi.
On the opposite you Arduino UNO will be happy with 4xAA batteries, and have voltage regulator to manage it (last but not least the Arduino ATMega chip can be replaced easily for 2/3 € bucks)
Perfect for Makers newbie
RaspberryPi Model 2 is a good companion for developing on the ride, and also for simple maker prototype.
Compared to other similar projects (like OLPC) RaspberryPi seems more humble and more cost-effective.
We also like a lot the fact there is no an heavy customization of the operating system, so the “average” Linux user can have a fast start.