1. darrenf's Avatar


    This is the third phone I've installed a Touchstone mod on, the earlier two being the Epic 4G Touch and Nexus S 4G. I think this is a little easier than either of those mods. As for longevity of a Touchstone mod, all three phones are still being used in my household and touchstone charging is still working on all three.

    To summarize the usual disclaimers: if you can't afford to damage your phone or void the warranty, you probably shouldn't open it and chop on it.

    That said, if you've ever used a Palm Pre with Touchstone charging you would probably agree with me that it can be to go back to charging by wire. I continue to be impressed by how easy it is to add touchstone charging to phones but I wish manufacturers would start implementing this out of the box.

    To start, you need a Samsung Galaxy Note (the GSM version is shown here) and a Palm Pre or Pixi battery door with inductive charging coil:



    Peel the charging coil out of the Pre/Pixi back and trim off the plastic backing behind the charging circuit (noted by the arrows):



    Place the Galaxy Note battery cover on the Touchstone and put the charging coil on top of it, letting the metal studs around the coil align with the magnets in the Touchstone:



    It is at this point that you should choose how you want the Note to line up with the Touchstone. In my case, to get good clearance between the table and the bottom of the Note, I placed the coil below the center-line of the back which means that it can't practically be rotated into the landscape position. If this is a problem, you can try centering the coil on the back and elevating the Touchstone with a shim instead. You can look at the finished product by resting the phone on top of the back:



    Using a knife edge, scribe an outline around the charging circuit to mark it's location, then remove the coil:



    Cut out along the scribe lines:



    Remove the charging coil and circuit from the plastic and foil that they are adhered to and place them on the inside of the Note battery door:



    [to be cont'd...]
    01-28-2012 10:51 PM
  2. darrenf's Avatar
    [cont'd from previous post...]

    Now remove the foil and metal studs from the plastic of the charging back and place them on the inside of the Note battery door:



    [Note: In this photo, I had trimmed the edges of the foil backing covering the coil. I did this previously in my Epic 4G Touch mod to reduce interference with the radio antennas on the sides of the phone. In this case, however, I later realized that I had trimmed them too much, resulting in inefficient charging. I also realized that the Note's antennas would not be affected by a wide piece of foil so I came back and replaced this with an untrimmed foil cover from another back (not shown in these photos). The moral of this is: don't trim the foil.]

    Next, place the Note battery door on a Touchstone (not shown) so that the magnets move the metal studs into the right locations and adhere them with a couple drops of Gorilla Glue Super Glue. Having tried CA cement in the past I was worried that flexing of the back would allow the studs to come free but I can testify (having tried to replace them later) that the Gorilla Glue Super Glue makes a permanent bond. I had to cut out plastic to remove the studs later when I was experimenting by moving the studs around. Hold the foil in place with electrical tape. This tape will be replaced later:



    Turning our attention back to the Note, separate the plastic surrounding the battery from the screen/frame/circuitry. I didn't document this step but it's easy. Remove six or so visible screws, none of them covered with warranty-void stickers (kudos Samsung) and then use a spudger or guitar pick to pry the two halves apart. There may have been some press-fit connectors that had to be disconnected, but they will be obvious and pry off easily:



    Now, remove the speaker/mic box from the screen/frame, again by removing a few obvious screws:



    Here is the USB port revealed:



    Looking at the reverse side of the speaker/mic box, you will see that there is a gasket surrounding the USB port:



    I didn't want wires to violate that seal, so I had to find a spot elsewhere on the circuit card to attach my charging wires. As it turns out, right behind the USB port is a surface-mount component that I can only guess is a capacitor to equalize surges in charging current. Fortunately for us, it's easy to solder to and connect to the positive supply on one side and the ground plane on the other:





    I don't know what gauge wire I used. I've heard others say that 30gauge will work. Given the short distance it will carry current, physics is on your side and you can use pretty light wire. Mine was taken from a USB charging cable so it was more than adequate. I chose it primarily because it had good insulation (required in the next step).

    Route the wires right beside the contact pins for the speaker (or mic - I don't know which). If your wires aren't well insulated you should put some fine heat-shrink tubing on them or something else to prevent shorthing them to the spring contacts:



    Because the speaker/mic box fits snugly to this circuit card, you will need to file down the area where the wires pass:



    [Admittedly not my prettiest work but it got the job done.] Reattach the speaker/mic box to the screen/frame. As you do, test to make sure that it's not pinching the wires and if it is, file down a little more.

    [to be cont'd...]
    01-28-2012 10:51 PM
  3. darrenf's Avatar
    [cont'd from previous post...]

    Turning our attention to the plastic back, cut a notch at the base of the battery bay for the wires to pass through:



    Attach the plastic back to the screen/frame, routing the wires through the newly created hole in the battery compartment:



    Install the battery to make sure that the wires will fit past it (no modification to the battery is required) and then solder the wires to the contact points on the charging coil circuit card. The wires are long at this point for easy testing -- we'll shorten them up before completing the project:



    For those who haven't worked with a Touchstone coil before, the wiring is quite simple. The charging circuit outputs +5VDC and ground to two large contacts:



    Scuff the contacts up with the tip of a soldering iron and they will accept solder tinning, after which they are easy to solder and de-solder wires to.

    Place a piece of electrical tape over the hole in the back cover/battery door that receives the charging circuit (not shown here). Place the battery door onto an energized Touchstone and confirm that the Note is charging:



    If everything looks good, de-solder the wires from the charging circuit, shorten them to the finished length (very short) and solder them back. Tip: after first soldering the wires into place as shown here, I discovered that having the wires run across the charging circuit caused the circuit card to protrude slightly from the back of the phone. To remedy this, I later de-soldered and re-soldered the wires. coming in from the other direction (across the plastic of the battery door). This let the back of the charging circuit sit flush with the back of the phone.

    Cover the foil, charging coil and charging circuit with electrical tape to prevent contact with the conductive-looking wrapper on the battery (not pictured).

    Snap the battery cover back onto the phone, paying close attention to the charging wires so that they don't cross (crossing them will introduce a small bulge in the back of the phone). Once the back is on, you're done!



    It's hard to photograph the thickness of the phone but here are a couple of attempts. Note: In addition to the tape covering the charging circuit, I put a wider piece of electrical tape further up on the back. This was just to provide some friction when it's in contact with the slick Touchstone:





    Virtually no impact on the thickness of the phone -- fantastic!

    I later went back and replaced the strips of electrical tape on the back cover with a decal. This has the added benefit of giving some traction when holding the phone by my fingertips:



    To see my other mods like a touchstone car dock and an easy-to-remove stylus, check out this thread on XDA:

    My SGN Hardware Mods [Photo heavy]

    -darren
    01-28-2012 10:53 PM
  4. bandit1091's Avatar
    I spoke with you a little bit on xda thank you for your help I did the mod on an old evo I had and am happy with it I'm going to do my note once I get the materials but I had one question I had planned on using this as a car dock I don't think the magnets would be strong enough to hold the note would putting stronger magnets in the back cover of the phone possible ly damage it?
    05-24-2012 10:14 PM
  5. darrenf's Avatar
    Good work on the EVO. I'm glad the mod went smoothly. To answer your question from the XDA thread, I don't know whether the AT&T Note has the same point to solder off as the Int'l Note, but I would bet that it does. It appears to be a capacitor which would be in place to stabilize irregularities in the current coming into the phone and that would be on any phone.

    That said, the disassembly video of the AT&T Note shows two surface-mount components at that location instead of three, so who knows. You should be able to test it out with a continuity tester. Be aware that the speaker/vibrate motor enclosure also appears to have antenna wires embedded into it on the AT&T Note which will be one more thing to watch out for.

    Regarding your question about magnets, I am using a touchstone in the car, with the phone mounted almost vertically. I added some Sugru around the outside of the Touchstone to make a larger, tackier contact surface. It's not perfect but it works well enough. You can see photos of it here:

    My SGN Hardware Mods [Photo heavy] - xda-developers

    If you look at other Touchstone mods, you'll see that some people are replacing the metal studs in the phone with true magnets to get extra stick. I would expect that it affects the compass, but other than that you should be OK.

    Good luck in your mod. Post lots of photos!

    -darren
    05-25-2012 02:16 AM
  6. legzez's Avatar
    Hi Darren
    Thank you for an excellent work and discription, i want to do the same to my SGN international version, can i run wires from the charging circuit directly to the battery to minimize soldring and cutting?
    thanks
    06-21-2012 03:01 PM
  7. darrenf's Avatar
    Hi Darren
    Thank you for an excellent work and discription, i want to do the same to my SGN international version, can i run wires from the charging circuit directly to the battery to minimize soldring and cutting?
    thanks
    Unfortunately no. Voltage and charge state information flow back and forth between the phone and the battery as usage changes from charging to discharging and in response to charge level and heat.

    The great thing about the USB port is that the phone is expecting a constant 5vdc feed from the port and allows for variability in current and, to some degree, even voltage, so we can feed it crude DC from the coil and the phone will tolerate it just as it would tolerate variances cause by different USB charging sources.

    If you move ahead with your project despite this, good luck and post with your progress!

    -darren

    Sent from my GT-N7000 using Tapatalk 2
    06-22-2012 12:56 AM
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