[MOD] Pogo Pin Charging for Verizon Car Dock

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ellesshoo

Senior Member
Jul 10, 2010
446
137
I posted this earlier in the long thread about the official car dock with pogo pins that has still not been released but I don't want to derail the main topic of that thread so here is a new one, with a bit more detail added.

I have the steps that I actually took to do this listed below. I think there is probably room for improvement and many ways to accomplish the same end result depending on whatever strong skills you may have or what tools you happen to have. Not every step has a picture associated with it because either I couldn't hold a camera and do it at the same time or it just wasn't worth it to photograph a mundane task like tracing a line.

Also, keep in mind I was doing this for a GSM nexus. I can test whether an LTE nexus (both standard & extended battery) will charge in the dock sometime on Tuesday or Wednesday.

Tools & materials used are described throughout. After the steps/pictures I have some concluding thoughts including some lessons learned, things I would do differently, and some alternate ideas others might wish to consider.

DISCLAIMER: Bad photography ahead.

Step 1: Grab a good beer, somehow these things always take longer than you expect.
p20900011024x768.jpg




Step 2: Tape the phone & dock where you will be measuring with a caliper or holding it in a vise. I used masking tape which turned out to have the extra benefit of being able to see the contact points through it. Take a lot of measurements. You end up drilling the dock blindly so your results all start in how carefully you measure things. Don't use the numbers on my caliper for your own use... Somewhere around the time of these pictures I accidently zeroed the caliper so I don't know which ones are showing correct values or not. I only realized this because I measured everything again and realized something wasn't right with the numbers.
p20900301024x768.jpg

p20900271024x768.jpg

p20900231024x768.jpg




Step 3: Double check your measurements, make sure everything is square... I want to say the following picture is over board on my part... but it really is a fine line between making contact b/w the pins and the phone 100% of the time, 50% of the time, or hardly ever.
p20900201024x768.jpg




Step 4: I used a pencil to trace a line from the contacts up the side of the phone, and onto the front glass. I then place the phone in the dock and put a new piece of tape from the edge of the phone around the edge of the dock and traced the line back over the dock so that I had a good reference for where to drill in the side-to-side dimension. The vertical dimension was purely based off my measurement from the face of the phone down to the contact points. Because the glass is curved, take separate measurements for each pin.
p20900181024x768.jpg




Step 5: At this point I used a 1/16" drill bit to make two holes and then pushed the pogo pins through. Before proceeding I hooked up 5V power using aligator clips to the pins and put the phone in the dock just to make sure everything was in the right place before I really made anything permanent. In this picture the pins are only held in place by friction. The dock is very rubbery at this location which is nice for holding the pins in place. You can see how well you lined up the holes by placing the phone in the dock and looking through the holes. You absolutely want to see the entire gold contact nicely centered in there. If not, fix things now before proceeding.
p20900371024x768.jpg




Step 6: I then took a car charger and cut the micro USB end off. There really isn't much to picture here. I happened to use a car charger with a permanently attached cord so there were no data wires. If you use a USB cord that contains 4 wires, usually red, green, white, and black, just tape off the green and white (date + & data -), and use the red (+ 5V DC) and black (ground). The pogo pin closest to the power button is the ground and the pin closest to the bottom is for 5V (I confirmed this for both the LTE & GSM models). Middle pin, assuming the same paradigm used for the nexus one, is for signaling the type of dock and the bluetooth id of the dock.



Step 7: I soldered the 5V and GND wires to the pins as described, sealed some exposed conductor with heat shrink, and used an epoxy to permanently seal them in place. You want to make sure you use an epoxy that bonds plastic and I would also recommend one that advertises some level of flex/gel. If it's too rigid or poorly bonded to plastic you could end up cracking off on the very first insertion. Make absolutely sure that the pogo pin plunger is the only part of the pogo pin that is on the inside of the dock. Even a small portion of the rigid part will cause you problems when you push the phone in and it pops the pins back out or damages the epoxy.
p21100611024x768.jpg





So, did it work...
p21100521024x768.jpg

p21100801024x768.jpg


After waiting enough time for the epoxy to set I got what I had hoped for.


I also added an NFC tag to the inside that I'm using to turn on bluetooth, set car mode, etc, etc...

p21100731024x768.jpg


p21100721024x768.jpg


Here's a few extra pics:
p21100631024x768.jpg


p21100661024x768.jpg


p21100601024x768.jpg



It successfully charges my GSM nexus with both the standard and extended battery. It would appear to me that the dock holds the phone with the position of the front glass relative to the lip of the dock in a constant position. So I'm assuming my wife's LTE nexus will be able to charge on the dock as well (will test on Tuesday/Wednesday). That would be really good news for VZW people who aren't up to the modification but would like to buy the GSM dock if it ever comes to market. At this point at least, it can concluded that it's possible to make a dock that charges the GSM model with both the standard and extended battery with the pogo pins in a fixed position.

Now that it's been done once the thing that would make this an extremely fast and easy mod in my mind would be a drill guide jig. An L-shaped jig with drill guide holes that you simple place against a reference point on the dock and drill in the holes and never have to worry about all that measuring and how well you measure.

I also wish I hadn't soldered the pins to a fixed car charger. Now I'm tied to that thing unless I want to cut the cord and splice a new USB plug on the end. In hindsight I actually wish I had used a 2 conductor "boot" close to the pogo pins that would allow me change the cord easy and provide some level of emergency strain relief or break-free ability if the cord were to get yanked. On the topic of strain relief, this is why I recommend right angle leads off the pogo pins. It also might be a good idea to adhere the cord to a spot on the back of the part that holds the phone so that a snap tug on the cord pulls on that and not your pogo pin connection. It feels very durable and I don't expect any problems it's just something I would recommend.

As for the NFC tag, I would use the thin adhesive tags, you don't want anything thick enough to change the contact position. I used a 1K tag so that there was plenty of storage for long instructions/information that may be handy to write to it. Right now it just launches car home, maxes the media volume, starts bluetooth, turns off wifi, and sets a high brightness level.

Finally, I wish I had gone ahead and installed a middle pogo pin with a free hanging wire lead off of it. Just in case I felt up to going down that rabbit hole in the future. I wish I still had a nexus one dock around to see if the signal pin on those docks would communicate on the galaxy nexus middle pin. I know, different OEMs (HTC) but the code is Google's so I figure there's a 50/50 chance it actually would work.





Your move, Samsung.
 

Jewremy

Senior Member
Jul 16, 2007
242
65
Boston
Definitely going to try this. Where'd you get the pogo pins?

Also, the third pin ::should:: be shorted to ground to trigger car dock, if that's the purpose of it.

Keep in mind that the OEM GSM dock plays music through those 3 pins somehow, though it makes no sense to me whatsoever. Not enough pins.
 

tjhart85

Senior Member
May 13, 2009
349
12
Definitely going to try this. Where'd you get the pogo pins?

Also, the third pin ::should:: be shorted to ground to trigger car dock, if that's the purpose of it.

Keep in mind that the OEM GSM dock plays music through those 3 pins somehow, though it makes no sense to me whatsoever. Not enough pins.

The stock docks play the audio over bluetooth since it'll help alleviate any grounding issues/hiss that may occur. One of the reasons they cost so much.
 

ellesshoo

Senior Member
Jul 10, 2010
446
137
Definitely going to try this. Where'd you get the pogo pins?

Also, the third pin ::should:: be shorted to ground to trigger car dock, if that's the purpose of it.

Keep in mind that the OEM GSM dock plays music through those 3 pins somehow, though it makes no sense to me whatsoever. Not enough pins.

Shorting to the ground is definitely not how the dock pin worked for the nexus one. Audio is also definitely not over the pin, its by Bluetooth. I've seen the code somewhere that insinuates the dock identifies whether it is a car or desk dock and its Bluetooth MAC. Shorting to ground isn't going to do anything.
 

ellesshoo

Senior Member
Jul 10, 2010
446
137
Definitely going to try this. Where'd you get the pogo pins?

Also, the third pin ::should:: be shorted to ground to trigger car dock, if that's the purpose of it.

Keep in mind that the OEM GSM dock plays music through those 3 pins somehow, though it makes no sense to me whatsoever. Not enough pins.

Pogo pins were left over from some other project. Take a look at digikey or someplace like it. Might have to search for "spring contacts" or "pogo pins/contacts".. different vendors seem to use different terminology.
 
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veli69

Senior Member
Jan 13, 2008
131
14
Hmm i don't understand the north to south measurement couldn't you extend the marks around the tape to get the height and the all you need is the distance from the top... not sure if that makes sense
 

mcso619

New member
Jan 8, 2012
1
0
The NFC tag can be hidden behind the glossy cover for the mount attachment. It's only held on by two all adhesive strips that run along the long edges of it.

Sent from my Galaxy Nexus using xda premium
 

ellesshoo

Senior Member
Jul 10, 2010
446
137
The NFC tag can be hidden behind the glossy cover for the mount attachment. It's only held on by two all adhesive strips that run along the long edges of it.

Sent from my Galaxy Nexus using xda premium

Good idea, I sort of like it exposed right now but I think I'll eventually do that.
 

ellesshoo

Senior Member
Jul 10, 2010
446
137
Hmm i don't understand the north to south measurement couldn't you extend the marks around the tape to get the height and the all you need is the distance from the top... not sure if that makes sense

Unfortunately I'm not sure I understand what you're describing. I'd like to know because I'm certain there are some clever and better ways then my own.
 

veli69

Senior Member
Jan 13, 2008
131
14
p20900181024x768.jpg

If you extend the holes with a pencil to top side of the phone on the tape when you put it in the doc you know their location, then all you need is your measurement from the top and you are all set.. I dont have a laser like yours though
 

ellesshoo

Senior Member
Jul 10, 2010
446
137

yea, that looks good. Actually looks shorter than the ones I used so I think it might be even better than the ones I used. Just did some searching on that site and found some that look similar to the ones I used http://search.digikey.com/us/en/products/829-22-003-20-001101/ED90504-ND/2416224. Looks like they come in a connector already but they're easy to remove from those kinds of connectors by just pushing the pins out. I like the style you found though. Ideally you don't want the lead part sticking out too far from the dock for a clean look so a pin that's just a hair bigger than the thickness of the side-wall of the dock is best. I say go with one of the style you posted over the ones that look similar to what I used.
 
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haleybob1228

Member
Dec 16, 2011
6
1
Would these work so you could have connectivity to all 3 pogo pins? I'd like to be able to play audio as well as charge the phone.

I *think* that might work. I grabbed a set of (older analog) calipers to measure the pogopins on my LTE GNex and found some estimates. It looks to me that the pogopins are spaced ~.112" apart (from center to center) and are ~.042" in diameter. The pins you found on digikey list the spacing between each pin to be ~.100" apart (from center to center) and ~.042" in diameter.
With those measurements in mind, there would be some slight overlap of the outer two pins onto the plastic casing but the pins would likely still strike the connector on the phone.
Keep in mind though that a number of users have noted that the center pin is not used for audio. I have no personal knowledge of this but I am passing the info along. Apparently audio is passed via bluetooth to a receiver in the mount which converts it to a line level output that is seen on the mount itself.

(Also, I guess I cannot include the hyperlink you had because I am too new to xda)

Update: I stand corrected, as noted later in this thread the spacing is .118" for the GNex pogopins. Apologies for the misinformation.
 
Last edited:
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rotus8

Member
Feb 6, 2012
23
10
The GN pogo pin spacing is 3mm (.118"). The All the Digi-Key pins mounted in strips seem to be .1" spacing which I think will be marginal, or at least make the position of the pins really critical.
 

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  • 34
    I posted this earlier in the long thread about the official car dock with pogo pins that has still not been released but I don't want to derail the main topic of that thread so here is a new one, with a bit more detail added.

    I have the steps that I actually took to do this listed below. I think there is probably room for improvement and many ways to accomplish the same end result depending on whatever strong skills you may have or what tools you happen to have. Not every step has a picture associated with it because either I couldn't hold a camera and do it at the same time or it just wasn't worth it to photograph a mundane task like tracing a line.

    Also, keep in mind I was doing this for a GSM nexus. I can test whether an LTE nexus (both standard & extended battery) will charge in the dock sometime on Tuesday or Wednesday.

    Tools & materials used are described throughout. After the steps/pictures I have some concluding thoughts including some lessons learned, things I would do differently, and some alternate ideas others might wish to consider.

    DISCLAIMER: Bad photography ahead.

    Step 1: Grab a good beer, somehow these things always take longer than you expect.
    p20900011024x768.jpg




    Step 2: Tape the phone & dock where you will be measuring with a caliper or holding it in a vise. I used masking tape which turned out to have the extra benefit of being able to see the contact points through it. Take a lot of measurements. You end up drilling the dock blindly so your results all start in how carefully you measure things. Don't use the numbers on my caliper for your own use... Somewhere around the time of these pictures I accidently zeroed the caliper so I don't know which ones are showing correct values or not. I only realized this because I measured everything again and realized something wasn't right with the numbers.
    p20900301024x768.jpg

    p20900271024x768.jpg

    p20900231024x768.jpg




    Step 3: Double check your measurements, make sure everything is square... I want to say the following picture is over board on my part... but it really is a fine line between making contact b/w the pins and the phone 100% of the time, 50% of the time, or hardly ever.
    p20900201024x768.jpg




    Step 4: I used a pencil to trace a line from the contacts up the side of the phone, and onto the front glass. I then place the phone in the dock and put a new piece of tape from the edge of the phone around the edge of the dock and traced the line back over the dock so that I had a good reference for where to drill in the side-to-side dimension. The vertical dimension was purely based off my measurement from the face of the phone down to the contact points. Because the glass is curved, take separate measurements for each pin.
    p20900181024x768.jpg




    Step 5: At this point I used a 1/16" drill bit to make two holes and then pushed the pogo pins through. Before proceeding I hooked up 5V power using aligator clips to the pins and put the phone in the dock just to make sure everything was in the right place before I really made anything permanent. In this picture the pins are only held in place by friction. The dock is very rubbery at this location which is nice for holding the pins in place. You can see how well you lined up the holes by placing the phone in the dock and looking through the holes. You absolutely want to see the entire gold contact nicely centered in there. If not, fix things now before proceeding.
    p20900371024x768.jpg




    Step 6: I then took a car charger and cut the micro USB end off. There really isn't much to picture here. I happened to use a car charger with a permanently attached cord so there were no data wires. If you use a USB cord that contains 4 wires, usually red, green, white, and black, just tape off the green and white (date + & data -), and use the red (+ 5V DC) and black (ground). The pogo pin closest to the power button is the ground and the pin closest to the bottom is for 5V (I confirmed this for both the LTE & GSM models). Middle pin, assuming the same paradigm used for the nexus one, is for signaling the type of dock and the bluetooth id of the dock.



    Step 7: I soldered the 5V and GND wires to the pins as described, sealed some exposed conductor with heat shrink, and used an epoxy to permanently seal them in place. You want to make sure you use an epoxy that bonds plastic and I would also recommend one that advertises some level of flex/gel. If it's too rigid or poorly bonded to plastic you could end up cracking off on the very first insertion. Make absolutely sure that the pogo pin plunger is the only part of the pogo pin that is on the inside of the dock. Even a small portion of the rigid part will cause you problems when you push the phone in and it pops the pins back out or damages the epoxy.
    p21100611024x768.jpg





    So, did it work...
    p21100521024x768.jpg

    p21100801024x768.jpg


    After waiting enough time for the epoxy to set I got what I had hoped for.


    I also added an NFC tag to the inside that I'm using to turn on bluetooth, set car mode, etc, etc...

    p21100731024x768.jpg


    p21100721024x768.jpg


    Here's a few extra pics:
    p21100631024x768.jpg


    p21100661024x768.jpg


    p21100601024x768.jpg



    It successfully charges my GSM nexus with both the standard and extended battery. It would appear to me that the dock holds the phone with the position of the front glass relative to the lip of the dock in a constant position. So I'm assuming my wife's LTE nexus will be able to charge on the dock as well (will test on Tuesday/Wednesday). That would be really good news for VZW people who aren't up to the modification but would like to buy the GSM dock if it ever comes to market. At this point at least, it can concluded that it's possible to make a dock that charges the GSM model with both the standard and extended battery with the pogo pins in a fixed position.

    Now that it's been done once the thing that would make this an extremely fast and easy mod in my mind would be a drill guide jig. An L-shaped jig with drill guide holes that you simple place against a reference point on the dock and drill in the holes and never have to worry about all that measuring and how well you measure.

    I also wish I hadn't soldered the pins to a fixed car charger. Now I'm tied to that thing unless I want to cut the cord and splice a new USB plug on the end. In hindsight I actually wish I had used a 2 conductor "boot" close to the pogo pins that would allow me change the cord easy and provide some level of emergency strain relief or break-free ability if the cord were to get yanked. On the topic of strain relief, this is why I recommend right angle leads off the pogo pins. It also might be a good idea to adhere the cord to a spot on the back of the part that holds the phone so that a snap tug on the cord pulls on that and not your pogo pin connection. It feels very durable and I don't expect any problems it's just something I would recommend.

    As for the NFC tag, I would use the thin adhesive tags, you don't want anything thick enough to change the contact position. I used a 1K tag so that there was plenty of storage for long instructions/information that may be handy to write to it. Right now it just launches car home, maxes the media volume, starts bluetooth, turns off wifi, and sets a high brightness level.

    Finally, I wish I had gone ahead and installed a middle pogo pin with a free hanging wire lead off of it. Just in case I felt up to going down that rabbit hole in the future. I wish I still had a nexus one dock around to see if the signal pin on those docks would communicate on the galaxy nexus middle pin. I know, different OEMs (HTC) but the code is Google's so I figure there's a 50/50 chance it actually would work.





    Your move, Samsung.
    10
    middle pin spdif verification

    I found this forum yesterday and was really interested. I also happened to be sitting in an Electrical Engineering lab so when people were asking if anyone had an oscilloscope to check out the middle pin I got right to it.
    I have to say it was a pain to keep bare wires in contact with the pins on my Galaxy Nexus (Verizon) but here is how I managed it.
    IMG_20120412_134441.jpg

    It may be hard to see but there are some small exposed wires in the bread board to make contact with the pins
    IMG_20120412_134448.jpg

    Zoomed out a little, red is +5V, black is ground, and white is the elusive middle pin.
    Setup.jpg

    There it is all together, the box was to weigh down the phone to keep contact on the pins.

    It took some work but I finally got a signal on the middle pin using an oscilloscope here is the result of that
    scope_3.bmp


    This didn't mean much to me until I looked up the spdif standard on Wikipedia
    I was able to decode the signal and find I caught a 32-bit subframe in that image
    the pattern 11100100 is the "W" preamble which means this subframe has information for the right channel, following that pattern is
    0000-Auxiliary-audio-databits
    00000010100011011111-the sampled audio
    0- Validity(error-flag)
    0- subcode-data
    0- channel-status-information
    1- parity bit (not including preamble)

    In the end the conclusion is that the middle pin does indeed send audio out through spdif. The only I can think to make use of it besides building your own spdif to analog converter would be to take the $90 Samsung dock apart and use that one in the car dock.
    3
    I received the usb cords last night and promptly put them in. I used a shorter 12 inch extension cable to run the female connector from the base to the pogo pins. I still haven't received the pins yet so I am still waiting on those.

    6964787123_821d30d855.jpg


    6818667044_ba0dc75155_b.jpg


    6818667248_97ca848509_b.jpg

    I had to remove the support rib to make room for the usb wire. I then drilled a hole to pass the wire through the back toward the phone. For the life of me I cannot figure out how they wired the OEM charger by samsung that has never come out.

    6964787747_e28c42dd14_b.jpg


    6964787935_76c114b858_b.jpg

    I had to remove this little support rib as well to make way for the female connector so it would sit flush with the bottom.

    6818668108_a76586a67b_b.jpg

    I modified the housing for the female connector so it would sit flush with the outside wall of the car dock.

    6964788585_bc991a84c1_b.jpg

    I measured and cut a small hole in the dock for the female connector to fit through.

    I started with my exacto knife to start a small hole and then used my drill to drill holes close to one another.

    I then cut out the small pieces in between the holes and smoothed the rough edges out with my exacto knife again.

    After that, I used epoxy once I made sure it would fit good. Here is a pic with the male connector plugged in.

    6964788845_586504516b_b.jpg


    6818668868_92cb7f33ab_b.jpg

    Here the case is back together and the wire is ready to be attached to the pogo pins (which haven't come in yet)

    6964789325_fd2a57e5aa_b.jpg

    All closed up and ready for pogo pins.

    6818669288_a5cb8b6894_b.jpg


    I added my NFC tag and it works fine on the back of the black plastic piece that says samsung on it. Now I am just waiting on the pogo pins to arrive so I can get this thing in my car.

    BTW all pics taken with my GN:D
    2
    Dunno if you guys saw this, but that shiny panel pops right off...uploadfromtaptalk1330392058279.jpg

    Sent from my Galaxy Nexus using Tapatalk
    2
    Another Pogo Pin part#

    Measuring the thickness of the dock surface that the pogo pins will have to be mounted through, I get ~ 3.63mm. This is approximate because the inner lining of the dock is a softer, rubbery material, so its hard to say whether or not im compressing that lining any with my calipers.

    With that measurement in mind, check out this pogo pin model on DigiKey:
    DigiKey Part Number: ED8182-ND
    MM Part Number: 0906-2-15-20-75-14-11-0

    From my best guess, it looks like these pogo pins will be just the right height to mate well with the phone, with about 1mm of pogo compression. I have some on order and I think they will work beautifully. I'll post my experience when they get here, but I judging from the OP's pics, these should be very similar to the ones he used in this mod.