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Forum Index : Microcontroller and PC projects : Raspberry Pi Compute Module
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psergiu Regular Member Joined: 09/02/2013 Location: United StatesPosts: 83 |
http://www.raspberrypi.org/raspberry-pi-compute Raspberry Pi in SO-DIMM factor, 512Mb RAM, 4Gb eMMC, all I/O pins accessible (46 available as GPIO), 2 CSI camera interfaces, 2 DSI display interfaces, HDMI & USB. + IO Board (reference implementation - exposing ALL pins) And all of them with open-source schematics, so you can build your own stuff. Looks nice, can't wait for a "cluster mother-board" - where you can plug multiple Pi DIMMs What do you think ? |
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Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Yeah, I have a Pi(the original unit, not the new SO-DIMM module). It IS very clever, and appeals to a lot of people for it abilities and it's cost, but I found that it was complicated to program in the supplied language, which I seem to remember was Python. Here is a clickable version of the link: Rasberry Pi Link HDMI output is a nice touch though, and I have seen this little thing used as a full-blown media player, so it certainly has it's pro's. However, I fell back on the MaxiMite in my case, as I did not need HDMI or fancy graphics, and it was really simple(the MM) to get going, and no need to load any kind of Linux to get it going. The Pi needs to boot up to a Linux of some sort before you can use it for anything, whereas the MM - you switch it on, and it is ready to rock and roll at the command prompt immediately. With my main code in the A: drive of the MM, from power up to system ready is 2 seconds, which is extremly good! In my chosen field(which is security systems), a nice fast recovery is always a good thing - you don't want to be waiting ages for a system recovery, during which someone COULD possibly break in, and the system would not alert anyone, as it was still chewing it's way through the boot-up! But I digress..... The Pi is a cute toy, and I probably WOULD have given it more attention, had it not been for the fact that the colour MM came along when it did, and I personally find MMBasic easier to program in then Python. ...only my 2c... However, the SO-DIMM module looks interesting - perhaps Geoff can port MMBasic to it? Smoke makes things work. When the smoke gets out, it stops! |
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mbramwel Regular Member Joined: 10/07/2013 Location: CanadaPosts: 42 |
The raspberry PI supplied language is not 'python'. Unlike the MM, the firmware is not atomic in nature. It is full Linux which means it includes python, c, c++, perl, php, bash, forth, fortran, basic, and about 200 other language systems and IDEs. Very insulting to call it a toy considering the specs of the board and the capabilities of the system, especially compared to the MM. I realize you were probably not serious and I am not trying to start a 'my computer is better than your computer' war. FYI: I believe Geoff already did a port last year. |
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Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
So noted. I would be interested in any link to a MMBasic port to the PI - would be worth checking out perhaps. "Very insulting"? My calling it a toy is a term of endearment, but lets not get too carried away about being easily insulted by an innocent enough comment. I think that perhaps there might be a colourful colloquialism barrier between us. Remember Bruce Willis in the first Die Hard movie, when he is told to use the touch-screen at reception? He says: "Cute toy." That was in the 80's, when touch-screens were the latest greatest new invention. But he was not being nasty about it. Smoke makes things work. When the smoke gets out, it stops! |
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mbramwel Regular Member Joined: 10/07/2013 Location: CanadaPosts: 42 |
sure - I'll accept all of that. Me? I was not insulted of course. Just want to make sure we all realize that these cheap ARM based wonder-boxes are encroaching upon the once unique micro-controller market. Even Intel recently announced a new max board (but I think Intel should give up in that market - too late, too little to offer) I am still enthralled over CP/M 80. It was the CP/M port that brought me to the MM. Unfortunately it was already a closed & forgotten project by the time my MM arrived. I use the PI and http://www.schorn.ch/altair.html to fix my addiction on REALLY OLD things (ok lets leave the missus out of it ) This might be interesting for you to check out: (long line to copy paste) http://www.thebackshed.com/forum/uploads/vk2sja/2013-07-25_2 35108_Linux_MMBasic_ReadMe.pdf |
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Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
The Pi is certainly NOT a "Toy" - that's just how I was referring to it, and I certainly am not bad-mouthing it. As I say - I DO have one myself - perhaps I should dig it out and have another play with it. The one I got was during that mad rush to get them, when they sold out so quick, so back then, there was not even a NOOB SD card - you had to compile you own Linux startup SD card, and that was out of my willingness or paitence, being a Windows guy - compiling kernels of Linux was not something I was willing to get into! I am guessing that has changed and become much less of a hassle then it was back then, by now....... Smoke makes things work. When the smoke gets out, it stops! |
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JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3816 |
There are now multiple different OSes available as well as versions of Linux (distros), partly because they've sold 2.5 million now. You don't have to run an OS on it - on reset it can load your own app right away - but not that many people actually want to do that on a board that is clearly intended and advertised as running an OS. John |
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Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
WOW! Did not know they had sold that many - that is very impressive. I think I will have to revisit this thing, just to see what is new since I last played with mine - I think I have a 256MB version, but I understand that the SoC chip they are using now has 512MB... Smoke makes things work. When the smoke gets out, it stops! |
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JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3816 |
Yes, started with 256MB and fairly soon moved to 512MB at the same price. 512MB is better for a modern OS like Linux where the tendency is to just run lots of stuff that isn't necessarily needed but is nice to have or which the typical person really can't be bothered to select out. You can run Linux in a few MB but you want to be thinking which features you want. Which is exactly what an engineer probably is comfortable to do (but may not want to take the time to understand Linux and how to do this). So... people tend to grab an off-the-shelf (well, off a web site) copy and go. Many of the people making those are software developers. Well, they stick in all the things THEY want (compilers and wizzy editors and ...). Which is why 512MB is better than 256MB! Now, a lot of people only really know Windows. They don't realise that Linux can have no GUI or a choice of GUI, mainly because Windows comes as MS want, regardless of what users want. An embedded Linux probably doesn't want a GUI, so is much smaller and faster (boots much faster, too). When you want a GUI but don't need a hugely fully-featured one, the good news is you can have that. But people tend not to realise that's true or which one(s) to choose and what the trade-offs are. The info is on the net but if you don't even know these things are possible and fairly easy then naturally who'd go looking for the info? Another thing people tend not to realise is that it's very easy on Linux to do things like: - run the GUI on one machine (maybe your PC) even though the app is on another (so, you might run a GUI app on a poverty-spec system with all the I/O on the PC) - cross-develop (such as compiling and linking an ARM app for the RPi on your much faster PC with its much bigger hard drive) The challenge with a board with so many possibilities, like the RPi, is to figure out what you'd like to do and then the best way to go about it. Sometimes it's to run with no OS. Or an RTOS. Or Linux. Horses for courses. John |
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MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Which minimal Linux (terminal only) would be best to use? What programming language would be best to use when you want the Pi to respond to interrupts? Can i control servos, lcd, keypad? Any libraries available? I am a noob what the Pi (and linux) concerns so having a starting point to study more about it would be really helpful. Microblocks. Build with logic. |
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JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3816 |
Those are just the things to read about or ask in the RPi forum(s). You're not the only person with such interests. An obvious issue to explore is would you want to use Linux at all if you want to be in charge of interrupts and so on? If you would, then why. (I'm not saying don't use it, but have reasons for/against.) Again, others have debated/decided such things and their thoughts can be very helpful. If you rely on building your own boards, or having them built to your own design, the new RPi compute module will be a huge help I think. The existing boards arguably didn't bring enough I/Os out. I've wondered about the idea of a umite connected to an RPi, using the RPi as an overall controller (with internet, SATA, etc) and the umite just to handle the lower level I/Os. John |
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mbramwel Regular Member Joined: 10/07/2013 Location: CanadaPosts: 42 |
I seems the OS that has the most support is RASPBIAN. It is debian Linux recompiled for ARM. It also has the raspberry centric drivers and support for the unique hardware on the raspberry pi. The rpi has a huge following and a nice *free* monthly magazine downloadable as a PDF. Since the sample programs are teaching Linux, most of the mag is a good read for anyone wanting to use any version of Linux. Another nice free source of info is the 'Linux Circle Magazine'. I use almost everything. I have raspberry, beaglebones, arduinos, MM and a bizarre set of other boards. They all have their pluses and minuses depending on the end use. I see the rpi and beaglebones as small computers with GPIO and not large micro-controllers that run full O/S (eg: http://gizmo.rootsgate.ca/ ) Excluding the 'Linux Circle Magazine' and 'Magpi' magazines, any other freely available magazines on the net? Links: http://fullcirclemagazine.org/ http://www.themagpi.com/ |
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JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3816 |
linuxcnc may be something of interest. I'm not sure if Xen is available for RPi. g-code is one way I know some people like to control steppers etc. John |
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