In an earlier post, I wrote about my personal tech road map, and the first milestone on that was to build the Raspberry Pi Laptop out of my Motorola Atrix 4G Laptop Dock and Raspberry Pi.
I can’t take credit for this, as the project idea and implementation has been around for at least 2 years. However, I did make some changes to the steps I followed, and modified my Raspberry Pi case to make the circuit board a little safer.
The Source Information
Back in March, my friend [wizard] sent me a link to a blog post about how to make a Raspberry Pi Laptop out of the Atrix 4G Laptop Dock (which I had purchased, and ended up being disappointed with its limited functionality).
I ordered the parts from the blog (which I have a modified list below) and waited 2 months for everything to get in from China. When I put it all together, I found there was not enough power from the HDMI cable/coupler/connector chain to activate the laptop dock. After checking out this forum thread, I realized I could ditch the extension cable and coupler, and just go with the micro-to-normal HDMI converter directly into the Pi board.
The [actually used] Parts List
This is taken directly from the blog post mentioned above, with my formatting:
- 1 x Raspberry Pi Revision 2 ( 004 ) ( although I hear a revision 003 may work )
- 1 x Motorola Atrix LapDock (UK , US)
- 1 x Female USB Micro to Male USB A connector (UK , US)
- 1 x Micro USB Female to Male extension cable (UK , US)
- 1 x Female Micro HDMI to HDMI Male connector (UK , US)
1 x HDMI coupler (UK , US)
1 x 30cm HDMI cable (UK , US)
1 x SKPang Raspberry Pi Starter Kit ( Optional )
1 x Self Adhesive Velcro for attaching the SKPang Breadboard area ( Optional )
- 1 x Edimax EW-7811UN Wireless 802.11 b/g/n USb Adaptor ( Optional ) (UK , US)
I didn’t have a need for Velcro or the breadboard components (he never described their purpose, and I didn’t bother investigating it). I also ended up not using the HDMI coupler or the HDMI cable, as mentioned before. I used a TP-Link Wireless adapter instead of the Edimax simply because I already had one. However the TP-Link Wireless adapter comes with its own headache of installing drivers. So go with the Edimax one if you have a choice.
The build process is pretty straight forward, as he describes in his post. The only change being Step 5.
In Step 5, instead of connecting all the HDMI components together, you’ve only purchased the one HDMI connector.
- Plug in the Micro USB Female to Male extension cable to the laptop dock’s Micro USB port first.
- Plug the Female USB Micro to Male USB A connector into the Pi’s USB port, but don’t connect the cable to the adapter yet
- Plug in the Female Micro HDMI to HDMI Male connector into the laptop dock’s Micro HDMI port next (because of the connector’s width and shaving, it makes it easier to do it in this order).
- Carefully slide the Pi board onto the HDMI Male connector.
- Plug the USB cable into the USB connector.
- Your Raspberry Pi should then start its boot sequence, flickering the ACT light after a few seconds, and the laptop dock’s screen should show your usual boot sequence.
The Caveats of the Raspberry Pi Laptop
One thing I found, by accident, was that closing the lid sends a power surge/signal to the Raspberry Pi board, and it causes it to power cycle. The same thing happens when you open it.
Now, as an owner of the Atrix 4G phone, I can tell you that this signal/surge causes the phone to come out of docked mode (where the screen functions differently on the phone) and that makes the phone go back to normal. Unfortunately, the dock doesn’t know it’s connected to the Pi, and not the phone.
So, don’t close your lid until you’re ready to power down. Once you do close it, disconnect the USB cable from the USB adapter…this saves wear & tear on the USB ports for your Pi and Dock (the adapter is cheap enough to replace).
I’ll have another post in a couple of days describing the modifications I made to my Raspberry Pi case to make the cable management better and circuitry a little more protected.