Raspberry Pi – any thoughts?

I’ve got an old “CherryPal” kicking around somewhere if anyone wants it?

You can’t expect secondary school teachers to be up to scratch with the very latest hardware and software, even universities struggle to get staff who follow the latest trends and teach the latest stuff as there’s so few people who can afford to time to learn all the new stuff AND do what they get paid for primarily. At degree level we’re often approached by uprocessor companies asking us to help them disseminate their new hardware to students, which we do, but generally it takes a few years to identify how to fit it into teaching, where it’s actually needed etc. You have to bear in mind that currently “average” students in an engineering degree will have very limited skills with embedded hardware even in their 2nd or 3rd year, because such skills come from real projects and their access to those is limited by other things such as knowledge in related fields. I was having this discussion earlier today as we have a 1st year course that operates with PIC micros programmed in basic (PICAXE’s) – the students enter with zero programming skills and leave having set up and programmed a 40 pin PIC to do a fairly complex task in 8 weeks. There was some concern that we were not teaching C and the processors are horrifically slow as it’s an interpreted language, but my argument is that this isn’t helpful at this stage – the students have no C knowledge and teaching C should be done in a course specifically for that so as not to introduce poor habits. Instead, we use the course to teach the basics of IO, memory and variables, program flow and branching methods – fundamentals. The next year they get C tuition. And the processor speed rarely affects anything, but those things that it does affect it highlights the requirement for interrupts rather than polling, so promotes good practice.

Ho Hum.

coffeeking has a good point – I think schools shoudl be teaching principles and techniques as much as possible.

It’s no good training 200,000 kids in how to program in VB if the world’s moved on but if you teach them how to strat to structure code and to understand why they’re doing stuff then that’s good.

Don’t forget, a GCSE is only about 60-80 hours actual teaching time – how much could you learn in a fortnight at work froma standing start?

Would make a great XBMC device by the look of it

Exactly what I was thinking. Signed up and ready to order

there’s so few people who can afford to time to learn all the new stuff AND do what they get paid for primarily.

True in industry also – the marketing and Gartner work 10x quicker than the actual usage in most places.

I’ll but buying a model B as soon as they are released, to add to all my other micro boards that sit about the place in varying states of completion. Pi has plenty of GPIO and the opportunity to expand the IO nicely – no reason why it couldn’t replace the arduino, that I see on first glance.

It can do much of what an arduino does, but where it is likely to not replace it is quite simple projects that don’t need the processing power. The big two reasons:

1)Battery life – running all the toys that it has on board is likely to mean a lot higher power consumption – they’re talking about using a 700ma supply, whereas you can just about scrape running an arduino off a 50ma supply, less if you use a more bare-bones board without the serial converter.
2)Simplicity – the raspberry PI is a proper computer, running a whole operating system – this means things like real-time stuff are less exact because lots of different bits of code are running. Whereas the arduino just runs your code and not much else, which makes things very simple to conceptualise.
3)Fast boot up – the arduino boot up time is about 10ms, so you just turn the switch on and it is working. I doubt a linux based computer is going to be this quick?

I’ve done stuff with Gumstix, which are fancy teeny tiny linux boxes a bit like Raspberry PI (not as neat and way more expensive), and replacing them with arduino was a real breath of fresh air, no complicated setup of boot-loaders, and changing programs is much quicker. But I’ve also done stuff with arduino where we could really have done with video output and a faster processor. So they both have their place.

Tempted by one of these for a play, might make nice replacements for some wireless sensor stuff I do…save me from the horrors of TinyOS* if anyone’s familiar!

*and intel x-scale processor manuals. *shudder*

@joemarshall I find the arduino something of a confusion though. It really is just a micro dev board (which are available) and some easy to access software. Programming a PIC in C is barely any more work, has the potential for even lower power use, smaller packaging etc while maintaining the RT capabilities. I have no more trouble teaching students how to use a PIC in C than I do teaching them to use an arduino, so I’m not really sure where it gains it’s popularity.

Pi does seem, on the surface, to be more software based and does have the added complexities of running an OS, but I’m not sure that’ll be a problem.

If you look at the bulk of the arduino uses, advanced users laugh at the fact that THAT is overkill for what it’s used for – you could do the same task with analogue components or some basic discrete logic. I don’t see many people using the Pi to do much more complex work, meaning it’s super-overkill, but at least based around an OS people may have had some contact with.

Hard to decide. The market will answer I’m sure.

Quite excited by this…will be buying a couple to teach my kids stuff.

@joemarshall I find the arduino something of a confusion though. It really is just a micro dev board (which are available) and some easy to access software. Programming a PIC in C is barely any more work, has the potential for even lower power use, smaller packaging etc while maintaining the RT capabilities. I have no more trouble teaching students how to use a PIC in C than I do teaching them to use an arduino, so I’m not really sure where it gains it’s popularity.

The big thing about the arduino is the community that they’ve built around it and the standardisation – the standard format, libraries for everything, a library of easy to attach hardware made by a multitude of people to do most things you want.

Yes it’s possible to do similar things on the PIC, but first you have to choose your development board from all the 6 million that are available, (which are often more expensive than an arduino board), then say you want to interface with a GSM modem, you have to find a GSM modem chip, hope someone has built a breakout board for it, or design your own circuit board, work out how to connect the modem board to your PIC development board, work out how to talk to the modem over serial etc. To do the same on arduino, you buy an arduino, buy the GSM shield (from anyone who happens to make one), plug it on top, and use the standard library to talk to it.

The same is true with the software, you just install one program, and plug the arduino in, and as if by magic you have a full development system, complete with a bunch of libraries for useful things built in, and many more available.

Another bonus of the arduino development boards is that they are open source hardware – this is great if you’re making anything real, because if you make something, then some point later, you decide you want to make another one, chances are someone will still be making the board, whereas with your PIC board, it is quite likely you’ll end up having to buy something slightly different (at least I can’t find the particular PIC dev board I’ve previously seen for sale anywhere now).

It also integrates very nicely into the eco-system of ‘Processing’ or Max/MSP on a computer + arduino for the hardware end of things, which arty types seem to like.

Oh and if you get stuck with something, there is a big community of people who will quite likely have done it on Arduino. So you can find example code / circuits etc. very easily.

You also don’t have to solder to do most Arduino things – even quite advanced things like GSM modems, GPS connection etc. can be done without any soldering. That might not be an issue for an electronics type, but a lot of people are really quite scared of soldering.