Raspberry Pi

[jlandells]

Originally Posted by whisper

So I better get with the kids

They have a special programming language called Scratch, that's aimed at teaching kids how to program by building their own simple games.

[jlandells]

Originally Posted by willk

"Unbelievable!"

Are you questioning my ability, sir???

[whisper]

Originally Posted by jlandells

They have a special programming language called Scratch, that's aimed at teaching kids how to program by building their own simple games.

I should fit in fine then

[jlandells]

Dad points: http://youtu.be/j6zseFi070E

[Poly]

I have one. What age is your son? I'd say that a normal under 8 isn't going to make any useful progress with it, although they could be guided through doing stuff with it step by step they wouldn't really understand. 8-10 they might be able to do some very basic stuff, 10+ and they can start to make real progress, but as JK says you don't need a RPi to do this. Much of this is just their ability to understand basic mathematical type concepts, read tutorials / information, and accurately type. This will mostly be copying or tweaking other people's stuff.

Probably need to be 12+ to really build anything meaningful by themselves. The earlier they start the quicker they will get there if they are interested.

As JK says though you can learn programming without one. The two main "languages" they use on RPi are Python and Scratch. Both can be downloaded (free) for virtually any computer. Scratch is a project from MIT and is really useful for learning with kids. Python is very powerful, easy to learn language used in a wide range of professional and scientific applications, which also provided a good foundation of learning other object-oriented languages.

Oh and there's a little "misselling" involved. The board (which can run 'headless') is < £30 (depending on version) but you'll need a memory card, a keyboard, a mouse, a display (or at least cables for your TV), a power supply, probably a wee box (or lego), a wifi card etc you could easily rack up £100 unless you've got spare bits lying around, and then it would be easy to add the £50+ on add ons like cameras etc. I'm not knocking the RPi project - I think its great, but its somehow been mispositioned as really low cost and a magic tool for programming when actually everyone with virtually any old PC could use both the main programming tools free of charge - its only when you want to add hardward/electronics or have headless boxes that the Pi gets exciting.

[ShinyShoe]

Originally Posted by Poly

Oh and there's a little "misselling" involved. The board (which can run 'headless') is < £30 (depending on version) but you'll need a memory card, a keyboard, a mouse, a display (or at least cables for your TV), a power supply, probably a wee box (or lego), a wifi card etc you could easily rack up £100 unless you've got spare bits lying around, and then it would be easy to add the £50+ on add ons like cameras etc. I'm not knocking the RPi project - I think its great, but its somehow been mispositioned as really low cost and a magic tool for programming when actually everyone with virtually any old PC could use both the main programming tools free of charge - its only when you want to add hardward/electronics or have headless boxes that the Pi gets exciting.

Well I think it depends what you want to program. If you want to program like we used to on a ZX spectrum and enter 1000 lines of code to make a union flag appear on the screen then I agree just download python or scratch or whatever and run it on a PC.

However if you want to be able to read data from peripheral sensors or output data to peripherals then they are a majorly easy solution. Reading the voltage from a circuit would require a £20 card usually anyway. The GPIO header is one of the major selling factors.

I agree you could spend a fortune creating some really snazzy stuff. You can do some really powerful stuff by creating Pi Farms with 20 of them all interconnected etc. But if you are happy to have a 5v circuit unprotected you need a 1amp USB Micro charger - most of us have one lying round these days. You probably need a network connection (you can wifi but it needs a card). You may want a keyboard, mouse and HDMI cable to put it on a screen. Bet you have a 4gb standard SD card lying round that will do fine. And you can use putty to remotely connect and just use it as a dumb terminal. If you were wanting to do something robotic it has major potential. They suck a fair amount of power so running on battery and solar power doesn't seem hugely realistic.

I'm about to replace a dodgy linux embedded router that feeds the weather station at my sailing club with one. It will need the Pi (£25), a SD card(£4) and a box (£7) and power (£4). Its hard wired to ethernet. We are debating installing some battery backup (hard wired to the GPIO) which at cheapest will be about £7, or maybe £25 if we go for something that can shut system down safely. Doing all that with a PC would consume far more power and if not using second hand would cost c.£200 without a UPS.

So all depends what you want to do. I'd suggest if its pure software and no need for a lightweight machine that you use a PC. If its to control things or sense things the Pi has a place. If its lightweight its one of a number of options. There are also a number of competitors which are more expensive (Beagle - higher powered) or more dedicated (arduino) to things like micro electronics.

[whisper]

Bugger me!

We better get these nav lights working or this might be another lobster pot thread

But seriously, if you were going to put a board in a rib, then how would the power supply work and what casing would be required, would cooling be required???

[HughN]

Originally Posted by ShinyShoe

Well I think it depends what you want to program. If you want to program like we used to on a ZX spectrum and enter 1000 lines of code to make a union flag appear on the screen then I agree just download python or scratch or whatever and run it on a PC.

Don't you mean 'enter 400 lines of code, knock the power lead and start again' or 'enter 1000 lines of code from a magazine, get really angry at it not working and then find they'd made a mistake in the code' (= learning)?

10 PRINT "HELLO "
20 GOTO 10

[Poly]

Originally Posted by whisper

But seriously, if you were going to put a board in a rib, then how would the power supply work and what casing would be required, would cooling be required???

Powersupply is essentially just a mobile phone / tablet charger (of appropriate ampage) so should be easy to wire in to the 12V, with the right bits.

Technically you don't need any casing, but practically you do. I'm not convinced there is any great benefit to using one on a RIB (its just another thing to go wrong - for what is pretty simple); unless you are trying to make a sophisticated "automatic survey 'logger'" and do clever stuff with it. You need to start with a problem to solve and work backwards not put it on a boat and try to find things for it to do.

It can essentially go in any waterproof case and needs no cooling.

[jlandells]

Originally Posted by whisper

But seriously, if you were going to put a board in a rib, then how would the power supply work and what casing would be required, would cooling be required???

You'll need a mobile phone power supply that can deliver 700-1000mW and a waterproof housing for the boat. Whilst the Pi doesn't necessarily need any cooling (as long as you're not overclocking it) I would be tempted to at least fit a heat sink of som description if it's going to be living in a sealed box. Also, if you're going to be controlling other on-board electrics with it, you'll either need space to add the additional components in the same box (and consider any potential heat that could be generated, depending on currents) or you might consider a second box alongside the main box for this purpose.

[ShinyShoe]

WAFIs have used them to provide wireless routing (pick up the marina Wifi and share it, use 3g if no wifi that sort of thing) plus provide some home moniotring - battery state, bilge level, bilge pump use, GPS location etc.

In theory you can run Open Charting Software on it. But then you need a screen which will cost you as much as a tablet but not have the portability to bring it home and play etc.

I'd suggest the Pi is useful for something headless (i.e. it sends data to another PC) or something that might output to a 16 x 2 LCD panel which can be done from a Pi for about £10.

But I agree (OMG) with Poly - find the problem then the solution. If the solution is a Pi thats great. But some of the WAFI guys say the Pi is overkill for some solutions and at 800mA of 5V power is eating 20 x what a Arduino could draw for the same task.

Just to note the power draw is up to 1A at 5V - so I think the power supply mentioned in mW above might have been meant to be mA. If I was putting this on a boat I'd pick one of 2 things:

- A 4 port USB socket something like this:
New DC 12V 24V 40V to 5V 4 USB Step Down USB Step-down Power Supply Module | eBay
to give me some extra USB charging ports for phones etc. or even:
12V Dual Car Cigarette Lighter Socket Charger Power Adapter USB Splitter 1A 2.1A | eBay

Both with a USB standard to USB mini onto the Pi power socket.

OR if I knew i had a permenant fix I'd just use something like this:

2014 New Waterproof DC Converter 12V Step Down to 5V 3A 15W Power Supply Module | eBay

(or a non encased version within the PI case) - connected directly to the PI GPIO

You might need to watch what happens with all of these when the engine is starting - the available voltage may drop to < 9V causing the PI voltage to drop out momentarily. There are means and ways round this using capacitors etc - if it was an issue the Pi community would soon find you a suitable circuit!

[ShinyShoe]

Another way to identify the problem might be to think... "what would I want to use a £300+ laptop for" on my boat and then see if a Pi can do it...

[HughN]

Originally Posted by ShinyShoe

...what a Arduino could...

Other microcontrollers are available...

[jlandells]

Originally Posted by ShinyShoe

Just to note the power draw is up to 1A at 5V - so I think the power supply mentioned in mW above might have been meant to be mA.

Yup! Fat fingers - small phone!

[whisper]

Went to Maplins and they only sell the kits with everything in so I'm going to look on line for one

A few of us might be getting together one evening to chat about it

I'll order one tomorrow

[ShinyShoe]

In that case you need to decide if you want an A, B, A+ or B+. A has 256Mb B has 512Mb. If you don't know the application got to be a B or you may find it under powered. BUT B consumes more power. B+ has extra USB ports which if you are putting a head on it will be very handy for the Wifi, Mouse, Keyboard etc. Not sussed out the A+ advantage. I have a B, bought a B+ for the headless weatherstation but may well actually put the B in that box and keep the B+ for my toy.

[whisper]

I want to build something for biffs sun seeker, doesn't matter if he doesn't end up using it though...

Biff has done so much for us so we could return the favour?

I think it needs to be controlled via an iPhone, he does have led lights fitted in two different colours and lots of other stuff going on.

I'm up for any ideas???

[ShinyShoe]

Mmmm... So now you need WiFi, a web page on the pi to do stuff. But u still don't know what stuff is...

[whisper]

OK, I think Biff has an iphone 4? (don't think a 4 has siri)

On Sunny he has 2 x led circuits, one is red to light the cockpit while night driving and the other is white to light the cockpit while moored up. There may be another set if he has underwater transom lights...

How it works...

Assuming the iphone can connect direct to the Pi using wifi and not the internet? (sorry i don't know how this bit works) It would need to work while walking to and from the boat.

So on the iphone there should be six commands:

White lights on
White lights off
Red lights on
Red lights off
*Blue lights on
*Blue lights off

*Assuming transom lights are fitted.

The Pi receives the signals and energises the required relay that is run in parallel to each led on/off switch.

How does that sound?? Probably completely wrong

[Bigmuz7]

Originally Posted by jlandells

Dad points: Making Fun: Mission Control Desk - YouTube

Holy sh*T ...... what a nerd ... but I kinda like it