Introduction: Charging Nexus One Dock
After my previous Instructable, I wanted to make a dock that was more widely manufacturable, and was capable of actually charging the unit while docked.
This dock is made from thin wood (lauan, .140" thick) and one small piece of 1/2" wood. Although I used my CNC Zenbot machine to cut the parts, the parts could easily be made using a dremel or even an exacto, with the lauan wood or maybe even some chipboard or cardboard.
It uses some readily available spring pins to provide the connection points for the charging. Currently, it does not activate the 'dock' mode, mainly because it appears to require a complicated information transfer with the third pin. When smarter people than me figure out how to activate the dock mode with the third pin, I'll be sure to attempt to include it in this design.
Step 1: Parts Required
I'm sure there are a lot of variations that are possible here, but I will list what I specifically used.
Approximately letter sized sheet of lauan wood, approx .140" thick (1/8"-3/16")
(Alternate materials are definitely possible, and I'll discuss what to do if the thickness is different)
3" long stick of 1/2" x 1/2" wood
(Again, this can be changed, but the material needs to hold the connection pins snug)
2 connector pins PRT-09174 from sparkfun
USB cord (or other 5V <1000mA source wiring)
Tool to cut the wood: either exacto, coping saw, scroll saw, or CNC router
3/64" Drill bit
Wire stripper (optional, or an exacto and band-aids)
Solder gun and soldier
Step 2: Cutout
Using the attached files, either cut out or CNC out the shapes.
To do the internal holes, a dremel could be used to drill in, or a drill bit and a coping saw could also be used. If the material is more like chipboard, an exacto would work perfectly.
If the material thickness is different, you will have to make the slots in the two side pieces to match the thickness of the material. The pdf indicates which slots.
Step 3: Drill Connection Pin Holes
For the connection pins, the holes have to be placed accurately.
Using the attached pdf as a guide for locations, drill the 3/64" holes. I recommend that you verify the hole locations with your phone prior to drilling, just in case there is variation in the cradled shape of this part. Also, the holes must be drilled in both the phone support and the cross member below. If you drill both parts at the same time, they will line up nicely. You could use tape to keep them aligned during the drilling.
The middle hole is optional, as I currently don't know how to use this pin connection with the phone, but I am placing it here now for the future.
Step 4: Assembly
Now to insert the pieces into the side parts.
Some trimming may be required, depending on how the internal holes were made. For myself, the router left all the slots with rounded edges, so I round all the edges of the parts that get inserted into the slots.
The fit up is a little tricky, as you have to get four pieces to slide into the two side parts at the same time. Fit each part together as a trial first, to make sure you don't have any individual fit up problems. Then, assemble all parts together. The parts should be snug.
Insert the pins in their locations. Pins should rise maybe 3/16" beyond the support. They will fully retract when the weight of the phone is placed on the dock. NOTE: we just drilled thru the cross member, so if you put the phone on at this point, the pins will probably get pushed down and through the cross member. We will fix this when making the wired connections. But its a good idea to verify the pins match the phone dock points.
Step 5: USB Connection
I made two holes to thread the usb cord through, which keeps it tight and prevents pulling on the soldered connections during normal use.
In this case, the red wire was the +5V source when plugged into the computer USB. The black was GND. I encourage you to verify this yourself with whatever cord you are using. Be careful and double check your work! I take no responsibility for anything you fry for any reason!
Solder the corresponding wires to the spring pins. Use heat to get a good bold between solder and pin. Use the soldered wire connection as the feature to prevent the pins from slipping through hole.
Step 6: Charge!
Once the pins are in place, plug the unit into a usb power source and double check the wiring. Once you are satisfied the +5V is going to the leftmost pin, looking at the screen, you should be good to give it a try!
If you have trouble getting the unit to charge, you may need to fiddle with the orientation of the pins somewhat. One way to accomplish this is to shift the phone support and the cross member relative to each other to get the pin orientation just right.