Ten pi-fect projects for your new Raspberry Pi There was an article a while back, in Scientific American I think, that posed the question: given a super-powerful computer, with infinite computing power shoe-horned into a coke can, what would you do with it?* The arrival of the Raspberry Pi (RPi) prompted a similar sort of question: given an (almost) disposable PC with late …
I have set up RasPBX on a Pi at home. I initially used the SPA3102 but could not get rid of the echo so I changed to an OBi110 which at about 35GBP is cheaper and much better. Now voicemails are attached to e-mails instead of hiding behind 1571, we can divert international calls straight to voicemail (as they are pretty much all nuisance sales calls) and with an additional Sipgate trunk and some Zopier soft phones we can have multiple simultaneous phone calls. Amazing for a little toy computer.
That answers a question I was going ask - the OBi110 with RasPBX. I have a, errmm, window of opportunity to muck around with this (couple of knackered DECT phones in the house). 35 quid for the OBi rather than 56 for the Cisco (on amazon at least) makes it easier to put the cost case to the CFO (wife...). Have an upvote, squire.
Running RasPBX here was well, though I managed to sort the echo out on the SPA3102 after some tweaking. Voicemails getting emailed, black lists, natty menuing system to filter blocked callers. No more junk calls!
Same Pi runs as an AirPrint/Cups server, and MRTG monitoring bandwidth, just for the heck of it.
I now need to buy at least one more Pi, probably two.
Also looking at the options to use them for exhibits at the local Aviation Museum (someone sits in a fighter jet, Pi senses it and plays audio, video etc)
At the moment, I'm working on a rPI intelligent thermostat. The rPI is going to be attached to the wall next to the boiler and will handle the mains switching to switch the boiler on and off.
The thermostat itself is an Arduino with an LCD display, telling you the temp and when it's next going to switch on, also the target temp. The temperature sensing is done with an LM35 temperature sensor, at the moment it's all hooked up with USB/Serial ports (and not to the boiler, yet) but will use xbee.
The rPi runs a mysql database and the system as a whole will allow rules based heating configured from web or the thermostat, such as:
On for an hour, on all day, off for a week, minimum house temperature (frost protection), daily scheduling etc. I'll be storing all the temperatures in a database and hoping to use this more intelligently in future...
This sounds neat.
In systems which have stored hot water it's possible to use two pumps and relay switching rather than the usual 3-port valve which tends to be prone to failure. The cost of an extra pump is similar to the cost of the valve, though non-return valves have to be included in each circuit and fairly careful design is needed to avoid unwanted thermal syphoning between the two loops when only one is in use.
Have a spare wireless thermostat/receiver that I'm cannibalising for actual switching. The transmitter is simple 3v pulse signal to an on or off pin (the actualy upload codez are all on the little daughter board thankfully).
USB thermometer currently in the post (£8 / ebay) and than it's all software - I'm hoping to persuade it to look up the outside temp & wind chill from the met office then reference a schedule of when the church hall is in use and calculate when to turn the heating on so it's suitably warm when needed. In winter, that can be 3am some weeks, despite having a boiler the size and power of the flying scotsman (probably about as efficient, too).
Thermonuclear boiler might be a suitable replacement, hence icon.
WRT Outside temperature - This is something that I'm going to be looking at, once the first stuff is in and running (my partner keeps on at me about "feature creep") but I'll be putting a sensor on the North side of the house, which should pick up temperature falls, you can then do pre-emptive heating which actually saves you a few hundred quid a year in gas.
What I didn't think is that I live pretty close to a Met Office site and a University where they have a weather station, also used by the Met Office, so all are probably online - it may well be worth looking to see if these are useable, and doing it in software rather than bodging together something else electronicy. That's got me thinking...
Switch to a one-wire bus with the DS18S20 temperature sensors and you'll be able to hook a lot of sensors up to it - I used to have them all over the top floor of my house, poking through holes in the ceiling with the bus in the loft. That way your thermostat can more inteligently decide when the heat is needed, and analysing the sensor logs will tell you which rooms are losing the most heat to the outside world.
I have been thinking about how to measure the temperature in all the rooms, I suspect that this will come under "feature creep", and I have been looking for an excuse to have a look at one-wire... The problem that I have is the house is a victorian terrace and it's not particularly easy to run cabling round the place, unseen at least.
I'd like to get motorised TRVs, so that individual radiators can be turned on and off automatically. This way, if I'm working from home, the office can be warm and the rest of the house at a minimal temperature. I'm not sure if these even exist though...
Motorised TRV's definately exist - we got them put in at work initially from Honeywell (not my project) - £80 per valve and £150 for the control panel to set the target temperature (on a schedule).
When I did my heating at home recently I looked for something a little more sensible in price - Pegler make a TRV that is motorised/scheduled target temperature changes all in one for around £25. Each room is now turned up and down to a schedule as necessary (i.e. kids rooms off while they're at school, dining room turns right down in the evening & our bedroom doesn't start warming up until 9 or 10). They can be adjusted manually at any point, and revert to programmed temp at the next scheduled change.
There's a USB programming stick and remote available (600MHz). The programming only has s/w for windows at the moment, but it's just a USB/Serial interface from what I can tell so that's a project for later on.
Victorian terrace should be easy! It has floorboards? You can push your low-voltage low-bandwidth wiring into the cracks between the boards in ine direction, and pull wires through the space between the joists under the floorboards in the other. Modern flat with a solid concrete floor is harder, though if you have carpet you can also easily put wiring under the carpet.
Very thin copper wire or tape attached to a wall, wallpaper-glued down with tissue paper and painted over would probably also work. I once attached a multi-element FM antenna to a ceiling that way (antenna made of aluminium foil, then papered over and painted). Worked a lot better than a dangly wire, and a lot cheaper than getting a man to attach a proper antenna to the chimney. The room needed painting anyway.
Or with RPi at £30 ... go wireless?
Sounds really interesting, and I don't want to be a spoil-sport, but it might be a lot easier and better to use the programmable Danfoss Eco Living TRVs available for about £35 from say Plumbnation or elsewhere:
http://www.screwfix.com/p/danfoss-living-eco-trv-sensor-head/91907
Then you'll have a thermostatically-controlled TRV, with a fully programmable seven day timer and local manual override, in every room. In our five-bedroom Victorian house, the variation in room warmth and use is such that a single thermostat and control in the hall (or wherever) isn't much use. I've even set up the controller in our dining room to heat up the room for my daughter's piano lesson on a Saturday morning after she complained it was cold. The controller is also beautifully intelligent, so if you say you want the room at say 21 degrees at 6 a.m. it learns continuously what time it needs to switch on to achieve its objective.
Buy the Danfoss valves and fit and programme in half an hour for each radiator (the TRVs aren't too noisy either and don't lose their programming when you change the battery like some others - beware) and build a lovely MAME games table instead, which looks seriously cool.
If you store temperature data, on and off times (and external temperature) then calculate the cooling curve you can probably save a good amount on gas consumption. Especially if you had a daily heat pattern (i.e. cold overnight) not just on/off etc.. It's a nice project, if you can build some intelligent software it would be great, especially if you're able to use a web server for remote control (or SOAP).
The big problem with any project along these lines is that you'll have to use a complete monitor rather than just being able to use the bare LCD. Adds a lot of bulk and inefficiency to the whole mess.
The DSI on the Raspberry Pi might as well not be there, there's no way to configure it, all the drivers are closed/proprietary/embedded in the GPU with no public documentation or toolchain available. Afaik, nobody's managed to actually hook an LCD up to it in any reasonable way. I really wish they'd fix this mess, because there are so many cool projects you could do with the added bit of size reduction.
..is to get the SD card to stay in the frikking socket! Returned under warranty, replacement exactly as bad!
Already had to take a file to the RS-supplied case, having noticed the case's dimensions seem to have followed my ex-manager's engineering principle:
"Measure it with a micrometer, mark it in chalk, then hew it out with a blunt axe".
Bloody case looked on arrival like it's been chewed by rats!
(Then, it'll become my webserver).
"..is to get the SD card to stay in the frikking socket! Returned under warranty, replacement exactly as bad!"
You returned it because the card fell out? I have to say that doesn't seem to be in the Spirit of Pi (tm). What's wrong with a bit of electrical tape, blu tac, or for a more-permanent-than-time-itself solution, a dab of silicone mastic?
No, Leswinger, the card wouln't stay in. Furthermore, the tiny bits of gold (as a switch), to detect whether a card was connected or not were buckled. (I guess I could've just somehow twisted the two together, but I couldn't find my glasses.....
When I've got money, I'll fire the bugger up with 16G card. THEN, i'll persuade the bugger with 16 Gig up its jaksy! That'll make its eyes water!
(That's the problem. I wanna change the card. Duct-tape, etc OK once I get the thing to boot, I'll use a memory stick. Until then however...)
@Ledswinger:
Bad as that. Put card into socket without case, card dropped straight out - vertically, not horizontally. So used a bit of tape, placed it in case. Micro-usb and HDMI sockets obscured by the case itself. Oh, and without a lot of cutting and filing of the SD hole, because it wouldn't sit in the case. Frick it, either it goes back to RS, or I buy and load a 32 gig. card, araldite it into position, drill the case to buggery, thus voiding any warranty I'd hoped for. Or, I solder in a better-quality holder. Warranty void again.I want to be able to change the SD, as-an-when I need to (they don't last forever). Now, again, extra time and expense to return it, and wait another month...Serious e-mail to RS going out today.
I didn't like the idea of the SD card sticking out of the case, so I bought a pIO adaptor from ModMyPi and used a MicroSD card instead:
https://www.modmypi.com/sd-cards-and-adaptors/raspberry-pi-micro-sd-card-adaptor
This doesn't stick out of the case, but you have to open the case up to change the card.
Sparkfun sell something they call the Pi Tin. I used it on four machines so far with no problems. Snap fit, securely closed yet easy to open if needed.
Only problem if you can call it that is that there is no blanking plug for the GPIO access port.
Cheapest case I've found, too. It would cost me more than $7 to build one from Lego.
Build your own Raspberry Pi rover: http://www.homofaciens.de/technics-robots-R3-construction_en_navion.htm
Watch the introduction video http://www.youtube.com/watch?v=tzfjiD4UI9g this will enable you to become a member of the IRDA, Interplanetary Rover Driver Association, then proceed to operate rovers operating inside distant universe. R3 control center on planet earth for the Curiosity Pi rover: http://www.homofaciens.de/technics-robots-R3-control_en_navion.htm
Earth needs more rovers!
Having a handy webserver you can upload files to from a browser and download from again is a good idea. I set one up myself. Not using a Pi - it runs on my home server/router. Just apache, some .htaccess files and one rather small perl script. You really need very little to make it work.
It is quite weak isn't it; no more than you will find people doing with other hacked together PC boards. There are advantages to the Pi - low power, compact footprint - but it is sometimes hard to see how it's really any better than a second hand laptop or PC costing £5 for the projects built around it.
What would be nice to see are projects which could not be done except with a Pi. Projects where the Pi brings something to the table, rather than just being a smaller version than how it would have been done before. There must be wearable projects it is being used in, applications for aiding disabilities, and things like that, something interesting, unusual, exciting, but all we seem to see are reinventions of the past.
The Kindle as a display is more a Kindle project than anything else. PC in a table, PC as a server, PC in a suitcase, PC connects to projector, PC connects to weather station, PC as another server wearing a "cloud" badge, PC connects to load sensors, PC running Asterisk. Yawn. Replace PC with Pi and it's still yawn.
Coming soon; bleeding edge experimenter connects keyboard, mouse and monitor to Pi to create a working computer.
I get the impression you are a glass half empty type of guy. If you had spent more than 3 seconds thinking about this, you would have realised that these are just some of the projects you can do. It's not an exhaustive list! Yes, you probably could do some of them using a cheap PC, but GPIO would be a problem, as would power consumption and size.
I suggest Google, and some thought.
PCs are typically small or cheap but not both. The PI takes both to a new level. It's like an AppleTV or Roku in this regard. You can try to make PCs smaller but then you end up with a $1000 Steam Box or a Mac Mini. It's also nice that the PI achieves it's cheapness without being some ancient thing you retrieved from a dumpster.
Who wants their cool project to fail because it's made of parts that finally decided to die of old age?
"You can try to make PCs smaller but then you end up with a $1000 Steam Box or a Mac Mini."
Though note that MicroATX form boards are commonplace, and there are plenty of small-size PC boxes. Not that I disagree with the gist of your post - in particular, these weren't around (or at least, not common) in the 1990s, so any £5 PC he finds from that era is going to be big. But there's a lot more choice than those two options.
Most people don't need a dedicated graphics card these days, meaning the days of PC cards are gone, similarly one can do away with the DVD drives.
I have a collection of old PCs in the loft and I use them mostly as a dumping ground. I often thought about leaving one on so I could connect to it remotely but could never justify it down to the cost of the electricity (even though it's not a huge amount) and the fact that I can hear the fans when I'm lying in bed.
The Pi has allowed me to do just this. It has a couple of 2.5" external drives connected, giving me 1.5 TB of storage, and I can always wake the others with a magic packet if I need to. I've got one port open to the outside world which is for openvpn, so I can usually only get in from my laptop, although I've set a friend's PC up to connect automatically too, so I can log on there to help him out (he's not a techie). His files are also backed up on the Pi.
I have an ftp server too, which I enable if I need to and it also has qbittorrent so I can download torrents when I want, wherever I am in the world.
The drives sit idle most of the time, as does the CPU. It's silent and consumes hardly any power. In short, it does exactly what I wanted my PCs to do, and it takes up very little space. I can't bring myself to throw the PCs out because I'm an electronics hoarder, and it's useful to have native i386/amd64 boxes every now and again. I wouldn't buy an old PC to do the job though. Not when the Pi is so cheap.
The marketing guys would call this set-up a cloud probably.
"but it is sometimes hard to see how it's really any better than a second hand laptop or PC costing £5"
Honest question - how easy it is to get such a £5 PC? Typically second hand PC prices tend to have a lower limit that's much higher than that, even if they don't seem worth it. And anything worth less than that is likely to be thrown out, so it's a matter of luck as to whether you know someone with some old hardware to give away. Admittedly Freecycle may help - but I can see the point that, just because a 1990s PC ought to cost £5, doesn't mean I can easily get hold of one, when most of them are now lost, collecting dust, faulty or thrown out.
A cheap web cam placed to capture visitors at the door, along with a similarly cheap microphone to capture the conversation all activated by the user pushing a button as they answer the door to a stranger. or even automated to recognise the door bell / knock.
The image and sound uploaded to a dedicated site where volunteers can quickly assess the situation and call the police if necessary to avoid another £5000 roof tile / spare tarmac / give us all your savings scam.
Or voip to a concerned relatives mobile where with the addition of a speaker to the system could talk directly to the "salesman" proffering some useful if not flowery advice.
I think the RPi would handle this and therefore bring the whole system in well under £100, which is nothing compared to the peace of mind it provides, then again I would bow to the wisdom of those here, who unlike me, are already engaging with this remarkable device.
Be careful with this. One issue they have had with the Pi is USB compatibility. My external drives used to be problematic but they fixed that with a firmware update. The cheapo USB camera I bought still has issues though.
There are some cams that do work, and they are working on the USB issues. Just bear it in mind.
Fairly challenging, but a case of open-source development once, fix hundreds of thousands of people's problem.
It ought to be possible to connect an Rpi, a solar panel, a battery, a weatherproof box, a USB hub, some USB wireless thingies and some directional antennae, to make a goes-anywhere wireless access point. Stick that on a pole in a field somewhere, with line of sight to another pole, and another, and another ... chain them together from a location that can get broadband, to a village or hamlet that can't.
Software that auto-assembles a network, so apart from configuring the broadband end the future problem abounts to errecting poles, screwing a box onto the top, and pointing the antennae in appropriate directions.
It's a cheap somewhat limited implementation of something that the military are playing with for battlefield communications, and disaster relief agencies for getting communications up again after a natural disaster.
It's not a new idea at all. Years ago I read about the installation of a working telephone booth at the Burning Man festival, using a chain of off-the-shelf routers strung across the Nevada desert. It's just that it's getting more affordable, and the RPi lets you integrate things like battery and power management to a greater degree. There are also quite a few routers that one can "jail-break" and convert into small fully programmable Linux boxes. (OpenWRT, etc.)
A related idea would be just to use a pair of solar-powered RPIs (or OpenWRT boxes) to wirelessly bridge a road. This is useful, because while you might persuade a few landowners to let you string a fibre across their land, just try getting permission to take a fibre over or even under a public highway. So, don't try. Just put a solar-powered fibre-to-wireless router on each side. You wouldn't even need directional antennae (which may not be entirely legal).
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