I wired it all up and did the USB data splice so the lapdock would recognize the RPI, but it won't boot. When I push power on the lapdock, the RPI turns on for a bit like it's starting up, then it turns off for about 30 seconds, and then the lights on both it and the lapdock flash as if something is happening, but then it all turns off. I edited the config.txt file for the RPi to have suitable parameters but I don't know why it won't start up.
I got the lapdock today. I looked up on youtube how to tear it down, and it turns out there's 4 screws on the back and 9 under the keyboard, which is a little tricky to pop out.
The Motorola Lapdock 100 is surprisingly small, but that's not really such a bad thing for a portable system. Inside there seems to be enough empty space for a RasPi A+ with the full sized HDMI port and USB port, or a RasPi 2B with the taller through-hole connectors removed, AND at least 2 USB drives for internal storage. All it looks like I'll have to do is dremel out some bits of plastic that are in the way, splice and solder a bunch of USB and HDMI, and maybe add a heat sink through the bottom of the case or put in a cooling fan. The cooling issue is a reason that the RasPi A+ may be better, even though it does not perform as well. However, the 2B doesn't generate much heat, so I'll try to make that work.
Additionally, there's a 10.8 V / 2200mAh / 23.76 Wh battery, which can be charged from a 19 V DC external supply and can be used to power the RasPi via USB. USB should be easy enough to splice 4 or 5 wires (usually isn't it just 2 signal wires and 2 power wires?... is #5 GND?), but HDMI (with 19 pins) will require continuity testing and pinout documentation to make it work, so maybe I'll look for a small adapter instead. The screen is very reflective which could be a problem for outdoor use; I may look for an anti-glare coating or film to apply to the screen. The HDMI should carry the sound to the lapdock from the RPi; if not, I'll wire audio output to speakers. I might add a stereo jack to allow the use of headphones.
priority to do list:
Remove plastic that's in the way with pliers and knife and/or dremel: done
Remove and re-wire RPi 2B through-hole connectors which are too tall. Two USB ports and the ethernet port will be moved to the large socket that originally held the usb/hdmi connector end, and then they'll be epoxied into place. One USB port will be used for an internal drive (although there's space for at least two), and the last one will be used to connect to the lapdock. This gives us ethernet and 4 external USB ports; one of the external ports can be used for wifi.
- A 11.6" motorola lapdock (droid bionic or atrix 4G models) will cost about $50
- A 10.1" motorola lapdock ("100" model) will cost about $40 (but it's soooo fugly!!!!)
So, I'll probably get one of these models soon when I find a decent deal.
However, I can get a working, complete, 5-15 yr old laptop (variety of models) almost gratis (the computer costs about the price of shipping it) on ebay or at a thrift store. (e.g., pre-lenovo IBM thinkpads... seriously, fuck lenovo)
- the main advantages of using the pi over a cheap used laptop with linux on it are the superior documentation / user support / community, and the GPIO
- a laptop will be hard to hack with the raspberry pi. I would need drivers and adapters for the LCD. SATA compatibility could be done but why bother. Instead I could replace the motherboard in a laptop with an UDOO, CubieBoard, BananaPi, etc, which have LVDS output!
I did some online research on what parts would be the most cost effective.
It seems that it could be significantly easier and cheaper to find a Motorola Lapdock and hack that, rather than get a separate battery, LVDS LCD display, VGA to LDVS driver board, HDMI to VGA converter, 3D printed case, etc......
In fact, I think it will be MUCH cheaper and easier to use a lapdock. I think now I should aim for under $100, not $150. However, I could still use a 3D-printed case/shell to attach the RPi securely to the bottom of the lapdock so no cables are exposed and so that everything is all in one streamlined unit that can be slid into a backpack without catching on things and ripping itself apart.
Since I'll be changing the list of parts, here's the current list for future reference:
1×Raspberry Pi 2 Model B - adafruit$40 + S&H
1×full size (11-12") keyboard with touchpad - amazon$25 shipped; hack to move touchpad below keyboard from the side
1×USB wifi stick - amazon$10 shipped
1×Acuvar Power Bank 13000mAh Dual-Port Portable Charger With LED Battery Life Indicator - amazon$15 shipped
1×4GB microSD card - class 10, with SD card adapter - amazon$6 shipped
1×13" LVDS LCD - ebay and MT6820-B LVDS driver board - ebayabout $30 + S&H and $10 shipped
1×active HDMI to VGA adapter - amazon or otherabout $10 shipped
1×powered USB 2 hub - dealextreme$6 shipped
1×3D printed caseabout $10 of filament??
1×screws & hinges + misc. wire, hot glue, solder + S&Habout $10 including adafruit + ebay S&H
lol, I started out looking at 6V 1.4 ah batteries that are $8 each... but that would be so heavy. and they are .95" thick