We are a gruop of students who want to make a kiosk system with embedded linux boards. We are now in selection phase but we could not decide which one fits to our requirements. Could you please help us?
- Minimum power consumption, since the kiosk will be powered with solar power and battery.
- CAN interface is a must, Rasperry Pi doesn’t have such an interface but it can be easily makeable at cost of power consumption (a seperate converter for CAN to uart or i2c will be needed.)
- No need for graphical outputs such as HDMI, Video out or so. The connection to the board will be over SSH.
- The grapics and text will be displayed on an monochrome LCD or e-paper to reduce the power consumption.
Thanks for helps.
BBB is a clear winner. Lower power consumption, more I/O, easier to do CAN, more reliable, more software options.
I think the BBB is the better choice as well, but you'll likely want to
measure real-world power consumption.
Neither board is really designed as a mobile platform, but the Pi is at
heart a set-top box (powered by AC), while the BeagleBone has it's roots
in tablet-like processors and has fine-grained control over powering
up/down different parts of the chip, CPU speed, etc. I'm not sure on
the Pi if you can disable it's probably power-hungry GPU that is
actually in control of the system (the ARM core is actually a secondary
CPU, the black-box GPU runs the show).
There are also likely some tweaks to be made with the BBB that will
reduce power consumption, specifically putting the HDMI Tx chip in a
power-down state. The on-board eMMC will also probably help with power
consumption, or at least help a bit with reliability (no uSD connector
to cause problems).
Finally, the BBB is actually engineered to be able to run off battery,
which is very similar to what you want to do, while I don't know if the
Pi has a means to work with multiple power sources.
Anyway, best of luck, and ask here if you go with the 'Bone and run into
According to what I have read you can not disable the GPU on the rPI, but you can minimize how much RAM it uses ( down to around 16MB it seems ) I would however wager if you’re not using the GPU, its power signature would be minimal.
rPI A seems to use up to around 300mA( but no onboard networking ), while the rPI B can use up to around 700mA.
I can vouch that the BBB can run from a computers USB port, so less than 500mA. Running from USB, I have boot from an external USB drive, with ethernet enabled., while loading the CPU at 99% load ( software test I wrote in C ) Minimal to no GPIO running. Aside from this however, I have not checked to see how much power the BBB draws. But I did run the above test for several hours. I meant to stress the board for the sole purpose of determining stability. It did not crash or glitch once.
From all the reading I have done the only real advantage the rPI has over the BBB, is a much stronger GPU. Power usage seems to be reasonably comparable where I’d bet the BBB has the overall advantage ( no hand on proof though ). Also, the rPI has the slight advantage of software maturity . . . But personally I like where the BBB sits software wise right now.
I have no love for the rPI personally, but I could see your project working on either. One thing to note however. If you’re going to be running solar to charge batteries . . .the BBB has the right peripherals and enough of them to act as a charge controller( with proper isolation and power mosfets of course ) . . . with plenty to spare. Something that is rather trivial to implement in C.
Thanks for replies. I have read somewhere (http://www.daveakerman.com/?page_id=1294) that the GPU of RPi can be deactivated but it saves only 20mA of power, which is not a big deal. Our system will consist of some other hardwares as well i.e. solar power control, RFID reader, CAN bus connection, 3G or GPRS connection, LCD, Keyboard etc. We decided to get a BBB as soon as possible
Mubin, how many kiosks do you plan to assemble?
For video player ,RPI win
We plan only 3 or 4 kiosks and there will be no video playing on the screeen. It will read RFID cards (maybe magnetic card or smart card) of some users and will ask for user passwords and then it will do some certain jobs. If unused it will be switched to sleep mode to reduce power consumption.
May my company donate you these commercial products for the kiosks?
Thank you very much for your offer. Of course your company may donate those products to us. I will contact you then.
Thanks a lot to everyone.
Will the power for the Canbus be supplied independently, and will the BBB need to control or manage that in any way? Depending on what is on the Canbus it may be more demanding of power than the BBB.