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Eben Upton Explains the Raspberry Pi Model A+'s Redesign 107

Posted by samzenpus from the straight-from-the-horses-mouth dept.
M-Saunders writes It's cheaper, it's smaller, and it's curvier: the new Raspberry Pi Model A+ is quite a change from its predecessor. But with Model Bs selling more in a month than Model As have done in the lifetime of the Pi, what's the point in releasing a new model? Eben Upton, a founder of the Raspberry Pi Foundation, explains all. "It gives people a really low-cost way to come and play with Linux and it gives people a low-cost way to get a Raspberry Pi. We still think most people are still going to buy B+s, but it gives people a way to come and join in for the cost of 4 Starbucks coffees."
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Eben Upton Explains the Raspberry Pi Model A+'s Redesign More

Eben Upton Explains the Raspberry Pi Model A+'s Redesign

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  • If they'd only make the thing faster with more RAM. It's pretty under powered for a modern single board computer. Sure, you can overclock, but why not just up the specs and call it a model C?

    • Re:Nice and all (Score:5, Insightful)

      by itamblyn ( 867415 ) on Monday November 10, 2014 @11:37AM (#48350761) Homepage
      Given the purpose of these devices, cheaper would be better than faster.

      • Re: (Score:2)

        by nwf ( 25607 )

        But faster wouldn't necessarily require being more expensive, or maybe add 15 cents to the price.

        • Faster would be nice, of course, but there are just scads of applications that don't require it. I use my pi B+ machines via SSH shell, not a desktop. In that environment, typically I have midnight commander up for both its editing capabilities and the simplification it provides for common operations; I write Python, which as one of the fastest scripting languages and really doesn't seem to be noticeably slow within the context of the B+. I drive relay boards (Sainsmart... the PiFace is a joke, severely lim

          • For lots of relays, two chips per 8 relays (Score:4, Informative)

            by raymorris ( 2726007 ) on Monday November 10, 2014 @02:40PM (#48352821) Journal

            > I drive relay boards
            > We have three here already, and I'm probably about to add a fourth.

            If you need to drive a lot of relays, you might consider a serial-to-parallel chip feeding a ULN2803 octal darlington array. That's about $2.50 of electronics per eight relays. With connectors and such, call it $0.50-$1 per relay. You can connect up to 256 addressable serial-to-parallel chips to a single IO on one Pi (or a PC, through a $2 level shifter). So for the price of another Pi, you can add 35-70 more relay outputs to your existing Pi.

            • Re: (Score:2)

              by fyngyrz ( 762201 )

              If you need to drive a lot of relays

              Thank you. No, I'm only driving four relays, so the SainSmart board [amazon.com] does just fine. Also, I'm a huge fan of opto-isolators.

              That's a great tip for other applications, though. :)

              In my setup as it stands now, two of the relays control the aeration and filtration pumps in my salt tank, and the other two let me turn an antenna rotor from anywhere on my LAN.

              For the salt tank, I tell the pi to knock the filtration pumps off for 45 minutes, which lets me clean the filter media w

        • More RAM is easy for A/A+, Faster is Hard (Score:4, Interesting)

          by billstewart ( 78916 ) on Monday November 10, 2014 @03:05PM (#48353239) Journal

          The Model A boards have 256MB, the Model B have 512MB. They could have put 512MB in the Model A, but it would have cost them a bit more and they were trying to make it cheaper. (I still wish they'd done it.)

          But one reason the board is so cheap is that it's using a System On A Chip that's designed for other applications, not custom for them, so making it faster, or using a newer ARM instruction set, or (apparently) putting more than 512MB on the board would be hard, requiring a major redesign and increasing costs. For instance, the BeagleBone Black costs about twice as much, and while it uses a faster CPU with a newer instruction set, the video processing part is slower, so it's not a total win.

          • Not sure where you're getting your Beaglebone Black's from, but over here in Aus they are about the same price as a Raspberry Pi from Element 14. I think my Pi's cost $35 for a bare board and the BBB cost maybe $45, but that came with a processor that's twice as fast and with 2GB of in-built memory. Once you added a memory card to the Pi they came to almost the same price - but the Pi ran about half as fast.

            I'd love a BBB with 1GB RAM, slightly faster CPU as well..but, for now, they're pretty good as is.

            • In the US, the Pi was $25 for the A (now $20 for A+), and $35 for the B (which is what I actually bought, but this discussion is mainly about the A/A+.) The Beaglebone currently runs $52-55 online, and has 4GB memory instead of 2GB (it was getting hard for them to find 2GB parts), and the processor's been updated a bit since last fall when I looked at it (it's also a newer ARM core than the Pi uses.) The catch is that if you want to do 1920x1280 video, you only get 24Hz, vs. 60 for the Pi, which affects us

            • That's fine if you plan on personal/small-scale use only. The BeagleBone folks expressly do not want people using their products as a part of other products-for-sale without discussing it with them first and, (presumably), getting their permission. So if you were to start ordering in production quantities you might find yourself suddenly without a supply of BBBs.

              The RPi has no such restriction.

      • Given the purpose of these devices, cheaper would be better than faster.

        Given the purpose of these devices, more energy-efficient would be better than faster. ;-)

        • This. B+ is really bad. They should work on really really low power states or something.

          • Re: (Score:2)

            by mspohr ( 589790 )

            They have... it's called the model A+

          • Re: (Score:2)

            by DamonHD ( 794830 )

            I have my RPi B+ running all my Internet facing services and running off-grid in gloomy London at under 2W, nearer 1.5W when I can fix some transient issues.

            http://www.earth.org.uk/off-gr... [earth.org.uk]

            And if I need something lower power I have Arduino-like boards that I run on microwatts, eg for battery-powered remote sensing.

            http://www.earth.org.uk/out/ho... [earth.org.uk]

            I see all the complaining about memory and speed but as someone who grew up with a Z80- and 6502- based set of home computers, then used Sun Workstations with a f

            • That's exactly my point. 700MHz/512MB is overkill for everything you might wanna do from such a portable device. The problem right now is that it draws too much current. I cant hook up a battery and carry it around in my pocket and expect more than 4-5 hours of uptime.

      • Re: (Score:2)

        by gweihir ( 88907 )

        Indeed. The Model A is something you use after you prototyped a design on the B. Unless your time is expensive in comparison to the deployment hardware (not always the case), you go do not production with the variant that has all the bells and whistles you do need for development and debugging, but not later on.

    • Re: (Score:2)

      by ssam ( 2723487 )

      They probably will at some point, but for now plenty of CPU and RAM for many tasks. There are plenty of other boards based around faster CPUs armv7 or x86 if that's what you need.

      • Re: (Score:2)

        by nwf ( 25607 )

        The three complaints I had were lack of IO pins, CPU speed and RAM. They did address the lack of IO pins, which was cool. Sure keeping them cheap is hard, but even phones have 1 GB of RAM now.

        • And of those 3 IO pins were trivial. It's Linux so your not going to bit bang an interface like an arduino the OS overhead is to touchy. You can add many i2c gpio with dirt cheap chips that still come in pdip format. You can not add more ram or cpu speed in a meaningful manner. If you need faster gpio SPI gpio chips are also plentiful and cheap.

        • Re: (Score:3)

          by psergiu ( 67614 )

          There are _NO_ 1Gb DDR1 chips in that form factor.
          If you can manage to persuade any memory factory to build a couple of million of them at a price simmilar to the existing 512Mb ones - the whole world will be thanful.
          All the 1Gb chips on the market now are DDR2 or faster - incompatible with RPi.
          Eben Upton & the Foundation has tried and failed - nobody wants to make so few 1Gb DDR1 chips for so cheap.

    • Here at work, people have built essentially the same project (USB control of relays) with three different platforms, an Arduino, an rPi, and an old Pentium with MBs of RAM. All three did the job.

      The Pi processor runs 44 times as fast as the Arduino, meaning it was 44 times as fast as needed for the purpose it was used for. The Pi has 512 MB of RAM, the Arduino accomplished the same task and has 2 Kb of RAM. The Pi has up to 16 GB of flash storage, the Arduino 32 KB.

      So they ALREADY did "up the specs" to a

      • Re: (Score:2)

        by itzly ( 3699663 )
        You mean: "44 times faster than needed, when all you want to do is USB control of relays"

        • As I mentioned, there is a large overlap between the applications people use Pis and Arduino for. That was one example I have recent personal experience with. If you want a computer with a few GB of RAM, there are several thousand options to choose from. We don't need one more 2-4GB computer.

    • Re:Nice and all (Score:4, Insightful)

      by LoRdTAW ( 99712 ) on Monday November 10, 2014 @12:33PM (#48351361)

      For most tasks, it has more than enough power. The pi isn't for people looking to use it as a PC replacement for productivity. It is a low cost board. The reason the RAM is always fixed at 512MB is because the cheap SoC (system on chip) is a PoP (package on package) design. Inside the chip you see on the Pi lives both the SoC and the RAM. There is no external memory bus so it is impossible to upgrade the RAM without redesigning the silicon and retooling an entire production line. That isn't going to happen because Broadcom isn't interested in upgrading an outdated (which is why it is cheap) chip.

      It's best use is an embedded controller that runs Linux. I have used one for a little home brew project and it works perfect. You don't need 700MHz for a control loop to turn relays on and off. But it does come in handy when you want to make a web based controller. I installed node.js and the cloud 9 IDE like the Beaglebone and I had a web page controlling relays in a matter of a few hours. Sure you can make a web based controller in a much smaller device like the Mbed but having Linux makes it much easier as you have a familiar development environment and tools. And you can write the software right on the Pi itself, no need for cross compilers, tool chains or a separate PC. Just a keyboard, mouse and monitor.

    • Newsflash! RPi is not the only kid in town!
      Quit whining and start exploring the market for a board that suits your needs. Sheesh.
    • Plenty of other smallish single board computers with more horsepower out there. It's not like you're forced to buy a RPi...

    • Re: (Score:2)

      by fisted ( 2295862 )
      I'd rather want it to be slower and use less power as a result. No, underclocking doesn't cut it.
  • I actually really like the redesign. One reason I didn't buy the previous Model A was that I already had a Model B in the same form factor. This one is nicely squared, will fit in a project box nicely, and is definitely fast enough for some of the project I have in my head. Plug a cheap wifi dongle in and you've got a great IoT platform to play with. It's on par for price with the CC3200 from TI, and while it doesn't have PWM it'll still do quite a lot and is significantly faster than the CC3200.

  • please for the love of all things holy... (Score:1)

    by Anonymous Coward

    Stop "incrementing" a model designation when there are serious changes to form-factor, pinouts, layouts, etc.
    This causes lots of breakage, e.g., B cases will not fit B+, due to multiple changes in form-factor and connector layout.
    B+ should have been called C, etc.

    • The model numbers are a nod to the BBC Micro, which came in models A and B, and later B+. Acorn Computers, which made the BBC Micro, later begat Advanced RISC Machines, better known as ARM. The Pi is the spiritual descendent of the original BBC Micro. Nice, eh?

  • How long until number of Starbucks coffees becomes the global cost basis across currencies?

  • Watch out Pi (Score:4, Informative)

    by LoRdTAW ( 99712 ) on Monday November 10, 2014 @12:51PM (#48351563)

    While the Pi is good for most of its intended tasks, it is lacking in many areas. The Beaglebone is a good upgrade but it too has shortcomings. But if you need more power, the Beagle team has another board in the pipeline.

    If you want some serious power for an embedded project look no further than the Beagleboard X15 [elinux.org]. This thing is going to be a beast:
    Dual core A15 ARM @ 1.5GHz
    2GB DDR3L RAM
    Dual core GPU (unfortunately PowerVR SGX, not open source friendly)
    2D accelerator and Video accelerator
    Dual C66x DSP processors
    Dual Cortex M4 Image processors (only one is user programmable)
    Dual PRU-ICSS ( programmable cpu accelerator to offload ethernet packet processing for industrial protocols like Ethercat, Profinet, etc.)
    eSATA
    USB 2.0 and 3.0
    Dual PCIe ports, Gen 2, one x1 and one x2 (Yes they will be routed to ports)
    Appears to have some type of video in, probably a camera port.
    And more...

    Rumored to cost about $150. Yes it costs much more than the Pi but you get what you pay for; a boat load of processing power and memory.

    • Re: (Score:2)

      by LoRdTAW ( 99712 )

      Also forgot to add dual gigabit Ethernet.

      • This seems like it is much more for embedded style applications. In this regards, it does just fine.

        If you really want a powerful Raspberry Pi, then the Banana Pi or Beagle Bone Black are some alternatives to look at.

    • Why not buy a cheap android phone and use that as your embedded controller? That would be cheaper and you'd get a much more efficient device.

      • And that's one of the three R's. [wikipedia.org]

      • Re: (Score:2)

        by LoRdTAW ( 99712 )

        Horses for courses. A phone is a crappy choice for a controller because the only I/O it might have is USB OTG. So you still need an Arduino or some type of USB I/O device. And you might wind up having to root the device, install 3rd party images and a whole bunch of other crap. In the end, the phone is a poor choice for more complex applications and is more than likely part of a proprietary walled garden. Plus you are stuck with Android, ick.

        Better off selling the phone or giving it away to someone who need

    • $150 to replace a a fried unit? You miss the #1 selling point of the RPi: it's easy to replace. Never mind the on-board features. It's the price. Any "competition" that can't approach that, is in a different market niche, and isn't really competition.

      • Re: (Score:2)

        by LoRdTAW ( 99712 )

        Perhaps you misunderstand. The Pi is cheap and can cover many basic applications. But it does not fit every niche. And it suffers from very poor performance in areas that some find unacceptable (USB ethernet, slow, inefficient ARM v6, limited GPIO, etc).

        Sure people have gotten the board to do basic image processing using OpenCV but imagine the potential power to be unlocked from the two C66x DSP's in the X15 SoC. Nevermind the fact that the A15 is over 3x more powerful than the ageing ARM v6 CPU in the Pi

    • Re: (Score:2)

      by Ichijo ( 607641 )

      A good middle ground for 45 Euros (about USD$56) is the OLinuXino LIME2 [olimex.com]:

      • Dual core Cortex-A7 ARM @ 1GHz
      • 1GB DDR3 RAM
      • Dual core Mali 400 GPU (open source friendly)
      • 2D accelerator and Video accelerator
      • SATA
      • USB 2.0
      • Gigabit Ethernet
      • HDMI (1080p)
      • LCD connector
      • MicroSD connector
      • 160 GPIOs

      • Re: (Score:2)

        by LoRdTAW ( 99712 )

        Yes, I have seen that board before. It is good to see an Open GPU on this board.

        The only big drawback to the Beagleborad X15 is the Lack of an open GPU. This is the same crap GPU that made the Intel Atom Cedarview and Pineview based systems utterly useless for running Linux. I still dont get what Imagination needs to keep locked up for their little GPU's. They can go jump off a cliff along with Nvidia. And why do companies insist on using PowerVR when Mali is quite capable, designed by ARM and more end user

    • Rumored to cost about $150. Yes it costs much more than the Pi but you get what you pay for; a boat load of processing power and memory.

      If you don't treat it as a computer like most people who don't use them then you already get way more than you pay for.

      The vast majority of the projects the RPi are being used for could be done by a microcontroller. So when you compare them against other devices used in the same application then for the same cost of an Arduino you get 15x the speed, 100x the RAM, and Ethernet, and OS with a complete TCP/IP stack ready to go.

      Anyone who really complains about the price of the RPi is expecting it to be somethi

      • Re: (Score:3)

        by LoRdTAW ( 99712 )

        The vast majority of the projects the RPi are being used for could be done by a microcontroller. So when you compare them against other devices used in the same application then for the same cost of an Arduino you get 15x the speed, 100x the RAM, and Ethernet, and OS with a complete TCP/IP stack ready to go.

        There certainly are a lot of overpowered Pi projects out there. Though, the biggest benefit is a full Debian Linux OS running on the board. You can easily create a really nice web based interface and run

        • No one complains about the Pi's price. In fact, it is its greatest selling point.

          I would provide citations for you but all you really need to do is scroll up. There's a lot of moaning about how the Pi isn't all that good and there are better boards out there for the price (then those same people are strangely quiet when asked to show one).

          I think the biggest problem is that people want the Pi to be more like the Beagleboards but don't want to pay for it, and don't want to lose the large community behind the Pi. The Pi didn't have a first mover advantage as much as a big advertising push

          • Re: (Score:3)

            by LoRdTAW ( 99712 )

            Okay, I see you point. Your original statement confused me as you stated "Anyone who really complains about the price of the RPi is expecting it to be something it's not." That made it sound as if the price was the problem, not the performance. Yea, performance wise it does suck but for most basic maker projects it is plenty. Most of those projects turns lights on and off or move an RC servo. Trivial stuff that an old 8051 could handle.

            The only device in the price range is the BBB. But it suffers from poor

            • If I were developing a board I would ensure:
              Tutorial for programming the board in several of the most popular languages: C, C++, Python and Java.
              Example code for access each of the I/O features, digital, analog, PWM, I2C, SPI etc.
              Thorough documentation on I/O access for writing libraries for other languages e.g. Rust, Haskell, Ada, D, Go, etc.
              Arduino C library for ease of application development and porting.
              Wiki wrapping all of this together so a user from novice to embedded superstar can waltz in and start writing code after a few minutes of browsing.

              Now that would be a Kickstarter I could get behind :-)

  • I am using mine as a web, email, storage and proxy server which works surprisingly well. Uptime is in excess of 60 days, although I have seen others reaching way more(I do patch my kernels after all).
    One thing I have noticed is that WordPress is an extreme hog when it comes to wasting resources, hence static sites help out a lot(as well as a PHP cache).

    Not really practical compared to a VPS but nothing beats having this warm fuzzy feeling of having your own underpowered hardware surviving against a hord
    • Consider adding "print server" to your list. Mine does pretty good with my Brother HL-1240 on the USB.
    • I use mine primarily as a wireless router, but also as a Transmission bit-torrent client, and there's also Apache and NodeJS running albeit not dealing with much traffic. Oh, and it's doing DNS duties too. My record uptime is almost 200 days... I decided to power it down before going on holiday!

      Funny the things you notice running slow though - for me, it's how slow PHP syntax highlighting is in Vim. JS is fine, but with PHP you really notice it lagging.
  • I'm doing an embedded project using the B+. The main reason why I like the B+ is that I'm using all the new GPIO pins from that model. The A+ has the same GPIO pins which is awesome on a lower price device.
  • Thank you for posting such a great article! I found your website perfect for my needs. It contains wonderful and helpful posts. Keep up the good work.Pulau Tidung [opiektidung.com]

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