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Raspberry Pi Model B laptop

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Hey Ben, I wanted to know if you can show me the best way to go about building a raspberry Pi Model B laptop, I need something light, simple and possibly good for someone with limited equipment. The idea is you have the raspberry Pi and you install the main things that makes a laptop well a laptop which in my book is a monitor, a mouse pad, a keybored, USB ports, WIFI, and battery system, I made up some blueprints but due to my limited software at the time of this idea it was made using a simple paint clone (Linux User). I found a image of something similar to what I want yet I was something bigger, more like a 13 inch or something, please Ben try it out or atleast tell me what would be a good alternative.

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  • The Motorola Atrix lapdock makes for a pretty good Raspberry Pi laptop.  One challenge would be to create a mounting enclosure for the Pi that maintains the atheistic of the lapdock.  Also, this teardown might be interesting: http://www.engadget.com/2011/03/05/motorola-atrix-docks-literally-and-figuratively-torn-apart-hack/

  • in reply to fustini

    That Atrix is awesome! We hacked a Pi into it a few months back and stole power off the USB.

     

    That did work, but if you plugged basically anything else into it, it browned out.

     

    Still very cool and certainly worth $90 if you can find one.

  • in reply to benheck

    Ben, I'm still looking for a schematic for the daughter boards from your 'retro' video.. Specificly, the level transition chip used..  Would a 74LS24574LS245 TTL chip work? or is there something more stable going back<-->forth from the 3.3V to 5.0V signals?  The only thing I can't figure, is would I have to change the 245's VCC to 3.3V for transition from a TTL level to the Pi's 3.3?

     

    Stephen

  • in reply to e14 Contributor

    I think I know which chip you're talking about, what project was it for?

     

    I've use level chips for AVR-to-SD since SD is 3.3 volts.

  • in reply to e14 Contributor

    gelfling6 wrote:

     

    Ben, I'm still looking for a schematic for the daughter boards from your 'retro' video.. Specificly, the level transition chip used..  Would a Re: Raspberry Pi Model B laptop74LS245 TTL chip work? or is there something more stable going back<-->forth from the 3.3V to 5.0V signals?  The only thing I can't figure, is would I have to change the 245's VCC to 3.3V for transition from a TTL level to the Pi's 3.3?

    A 74LS24574LS245 is a 5V part and needs 4.5V to 5.5V to operate properly.  With a 5V supply, outputs typically reach 4V which is too high for RasPi.

     

    What converter circuit you need depends on which way the signals are going.  For example, if you're trying to convert a 5V output to a 3.3V input, you can get away with a resistive voltage divider, such as in this thread chez RasPi: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=45&t=22841 

     

    If you want bidirectional 5V protection, I like using an FET bus switch such as the IDT QS3245.  Here's an IDT app note on the subject: http://www.idt.com/document/11-5v-and-3v-conversion-zero-delay

     

    There's been lots of discussion on this topic at raspberrypi.org.  I recommend entering "5V level converter" in the Google search box on the top page and see if you can find something that matches your needs.

  • in reply to benheck

    Benjamin Heckendorn wrote:

     

    I think I know which chip you're talking about, what project was it for?

     

    I've use level chips for AVR-to-SD since SD is 3.3 volts.

     

    Hi Ben, This was in reguards to the Retro desktop using the Pi. (like the BBC micro)..  I was looking for the schematic, or at least a parts list for the daughter boards you were plugging in..  My main worry, is frying the GPIO of the Pi.. (and, as John Beetem just replied, Yeah.. scratch the idea of the 74LS24574LS245 as a buffer backward from 5V down to 3.3..

     

    John Beetem wrote:

     

    A 74LS24574LS245 is a 5V part and needs 4.5V to 5.5V to operate properly.  With a 5V supply, outputs typically reach 4V which is too high for RasPi.

     

    What converter circuit you need depends on which way the signals are going.  For example, if you're trying to convert a 5V output to a 3.3V input, you can get away with a resistive voltage divider, such as in this thread chez RasPi: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=45&t=22841 

     

    If you want bidirectional 5V protection, I like using an FET bus switch such as the IDT QS3245.  Here's an IDT app note on the subject: http://www.idt.com/document/11-5v-and-3v-conversion-zero-delay

     

    There's been lots of discussion on this topic at raspberrypi.org.  I recommend entering "5V level converter" in the Google search box on the top page and see if you can find something that matches your needs.

     

    The 74LS24574LS245 circuit is what I came up from, with the google search.. But, it still struck me as begging for trouble if you tried returning the signal, but not reducing the VCC voltage. 

     

    There doesn't seem to be much in the way of DIP chips (Sorry, I'm still back at the Breadboard experimenter level..)  for this putpose, except specialty chips..  I saw something about the TI sn74lvc8t245 , but can't find suppliers..  (and at present, on a zero income/purchase budget. So, trying to obtain a free sample, without a Company name, kinda defeats the purpose).. (I'm just a shade-tree hobbyist/experimenter/tinker.)

  • in reply to e14 Contributor

    Most MCU hobbyist stuff uses a buffer as level translation.

     

    You power the buffer with the target voltage (usually 3.3 volts) so it outputs at that level.

     

    Some 3.3v stuff is 5 volt tolerant, but the Raspberry Pi isn't. So you'd want to knock 5 down to 3.3 before letting it into the Pi.

     

    However, 3.3v coming out of the Pi is enough to trigger 5 volt logic, so you don't need a buffer in that direction.

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  • in reply to e14 Contributor

    Most MCU hobbyist stuff uses a buffer as level translation.

     

    You power the buffer with the target voltage (usually 3.3 volts) so it outputs at that level.

     

    Some 3.3v stuff is 5 volt tolerant, but the Raspberry Pi isn't. So you'd want to knock 5 down to 3.3 before letting it into the Pi.

     

    However, 3.3v coming out of the Pi is enough to trigger 5 volt logic, so you don't need a buffer in that direction.

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