Intro: Linkit One Antenna Mounts & Upgrades
I was happy to see the Linkit One kit included all the necessary parts to get going except an SD or sim card....
This made it so easy to jump into the tutorials and get it working. Even testing the Flash File routines was easy using the internal 10Mb flash.
The hairy part was those antennas flopping around.
Step 1: Using the Stock Antennas
My first thought was to mount it on a plate. I had a couple of dozen of these Turtle bot plates I got from I Heart Engineering. According to their site:
The adapter is made of 1/4" thick Acrylic featuring 16 Brass Heated Inserts for 4 different hole patterns that comfortably accommodates the Beagle Bone, Raspberry Pi, and Arduino suite of Boards. It comes ready with Board Adapter Plate, (4) M3 1/4" spacers, (2) M2.5 1/4" spacers, (6) 10mm M3 socket head screws, (2) 10mm M2.5 socket head screws, and (4) 10mm M4 thumbscrews.
I don't work for them or know them well but they are a local Brooklyn company with really nice staff.
These are really cool mounting plates to have around. There is enough room under the linkit to hide the battery too. I gave a demo at a library where I had over two dozen different boards mounted to an easel using these. Any plate will do, even old piece of Pergo flooring...
I mounted the Linkit to the plate easily since it has the standard Arduino hole pattern. I was a little concerned about the two screws that go through the RF shield plate but when I peeked under that plate I saw two nylon spacers! I used some velcro to attach each antenna to the board. Not bad way to start.. But thats too easy.
Step 2: Making Something Better
Well I can never leave anything alone so I though about moving the Linkit One to a larger plate.. Then I could print this really simple antenna cover to keep all them completely safe.
I never got to print it because I had a better idea before I got to the workroom.
Here's the Scad source and an STL file if you want to try it.
I may redo this to cover the Linkit itself but my intent is to have as much visible as possible.
Step 3: GPS Antenna Mount
The 3D printed cover was a good idea but I only needed the GPS antenna. I had other plans for the rest.
I made this simple cover. My original plan was to mount the Linkit to the underside of a project box lid and and drill 5 holes in the pattern of the 5 face on a die right near the GPS connector. This way the outer 4 holes are for the mounting screws and the center hole for the antenna lead.
Right after I printed the part I decided to make a cover for the box. This way it could be used with my proto plate. I added a relief for the cable and this made a perfect little block.
Just use a little foam rubber to keep it from rattling around in the box. Luckily I had the soft side of the velcro already on it. Don't worry that black velcro is not conductive. I checked it to be sure.....
I used standard PC case screws to hold the lid on.
I used a little double sided tape to mount it off to one side. In the first picture you'll notice a plexi mount that would have had it mounted centered on the plate. I changed my mind about that when I decided to mount it to one side to make room for an antenna connector bracket.
Step 4: GSM and WiFi
Now with the GPS Antenna done I opened the Zigbee drawer and grabbed these U.fl connectors.
I also had a bunch of different sized WiFi antenna;s from old scrapped access points.
Wifi antennas use what's called a reverse polarity SMA connector. All that means is that the center pin is on the opposite side from the standard SMA connector.
I got these GSM antennas from eBay. They use standard SMA connectors so I had to get a couple of matching antenna cables too.
The nice part is you can't plug the wrong antenna into the wrong jack outside board.
As long as you don't confuse them at the board itself your good.
I also got a full sized mobile phone antenna and it too has an SMA connector. This will be nice for an automotive tracker project.
Step 5: Mounting the Antennas
If you just plan to use one of the antennas I get these little "L" brackets at the hardware store. Since I wanted to have both I grabbed a piece of aluminum angle about 1" on each side. i cut a piece 2" long and then trimmed about 3/8 off one side.
I used a couple of existing holes on the plate. If you're using a bare wood plate space these out a bit.
I tucked the wires under the GPS Antenna and now have a pretty sturdy development platform.
Step 6: The Finished Product
I found a bunch of different antennas and they all seem to follow the standard of Wifi - RP-SMA and Cell - SMA.
It came out so well this is the board I will use at the next demo I give.