I just noticed that there is a pair of contacts on the inside of battery cover and matching spring loaded contacts in the housing, next to the lower left and right corners of the battery. Anybody knows what are they for?
If they are really electrical, is it possible to detect from software if the bettery cover is removed? Not that this could be used for anything useful, but just curious if that's possible.
vponomarev said:
I just noticed that there is a pair of contacts on the inside of battery cover and matching spring loaded contacts in the housing, next to the lower left and right corners of the battery. Anybody knows what are they for?
If they are really electrical, is it possible to detect from software if the bettery cover is removed? Not that this could be used for anything useful, but just curious if that's possible.
Click to expand...
Click to collapse
I'm just guessing but I know that the first version of the car kit involved replacing the back cover....so...I'm guessing it relates to having the car kit plugged in and just putting the phone in the kit without needing to attach a cable in the phone each time.
Did I mention that I'm just guessing.
n11 - Good guess.
Thanks for the tip. So, from what I understand, these contacts are for power supply, correct?
vponomarev said:
Thanks for the tip. So, from what I understand, these contacts are for power supply, correct?
Click to expand...
Click to collapse
Well...since Mega Maniac has given such strong support to my guessing ability I'll answer this way: Yep, I guess the contacts are for the power supply.
The contacts are probably for proper grounding since the battery cover is metal. It would be bad to have a static charge differential build up on the cover take out the circuit board. Or it may be that the cove is the antenna. But I doubt that. Just my opinion.
I was thinking within the same line, but more like bettery cover being a shield to prevent any external radio interference. But power connector theory sounds more reasonable. I'm NOT going to verify this theory by applying 5V to these contacts.
vponomarev said:
I was thinking within the same line, but more like bettery cover being a shield to prevent any external radio interference. But power connector theory sounds more reasonable. I'm NOT going to verify this theory by applying 5V to these contacts.
Click to expand...
Click to collapse
I'm now guessing that you are a very smart person...grin.
Just for the record I dont have the HTC navigation car mount, but if you are talking about the teo connections either side of the back cover then I cant see what else it would be. Essentially my opinion is as much of a guess as n11, but I would bet my HD2 on it, because there is just about nothing else it could be.
I'd like to know for certain what these are for as well.
Grounding
These connectors are probably grounding, if you see on the cover the paint is striped away where the connectors meets the cover.
If this was in anyway connected to the battery for charging it would short out the battery since the cover is made of metal.
Just Checked With my multimeter and there is a direct connection between the two points, and also between the screws and the two points, so grounding it is.
I didn't buy the HTC extended battery but one from amazon sold by Karen Deals. Link is below
http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=0NVM3EA1B2VE9HN3AKMA
Battery
Model No: cs-ht8585xl
Part No: 35h000128-00m, ba s400
Rating: 3.7v 2400mah
Lithium Ion
Induction Unit
Palm Pixi charging back with Palm touchstone charging dock
Operating System
Shubcraft 1.4d
Video:
Images are attached below!
Induction charging has the same charging speed as plugging it into a wall outlet. Very fast!
Sidenote:
I tried using a multimeter with the 3 contacts located under the battery and could not get it to register anything (with and without the charger plugged in). I then tried shooting 5v through it using 6 different combination (2 plugs for 3 contacts) and still couldn't get anything. If anyone knows a way to use these 3 contacts for charging please leave feedback. Also if anyone can find a minature microusb male connection that'd be great.
Well done, it's a really nice mod!
The 2400 mAh is a bit too bulky for me, though the extended uptime must be awesome. I'd even consider something similar, were it not that you're using the microusb to charge. If only you could connect it straight to the battery, would be so much more convenient. It'd still work in for instance car kits and attached to a pc.
Never the less, well done.
Looks great, i would try this myself but i cant stand the bulk of extended batteries and the stock metal back would almost defiantly interfere with the current. Where did you get the decal from?
Angelusz said:
Well done, it's a really nice mod!
The 2400 mAh is a bit too bulky for me, though the extended uptime must be awesome. I'd even consider something similar, were it not that you're using the microusb to charge. If only you could connect it straight to the battery, would be so much more convenient. It'd still work in for instance car kits and attached to a pc.
Never the less, well done.
Click to expand...
Click to collapse
You can't plug in directly to the battery since the battery doesn't have a balancer board on it and it would explode if it were to be overcharged without one.
JJbdoggg said:
Looks great, i would try this myself but i cant stand the bulk of extended batteries and the stock metal back would almost defiantly interfere with the current. Where did you get the decal from?
Click to expand...
Click to collapse
I got the decal in the automotive section of Walmart. It came with 2 big/4small stickers for 7usd
UPDATE: Made the microusb head smaller! Letting liquid electrical tape dry then I'll post pics.
this is a really nice mod. what about the possiblly of going via the nav panel connectors instead of micro usb. this would as far as i know leave the usb port free and also not have the disadvantage of having a usb connector attached which can be easily damged.
Personalyu i wouldnt do this mod as i use my phone to tether a hell of a lot so it seems pointless to me, but being able to just sit your phone down and have it charge is awesome.
Great work!!!!
veda_sticks said:
this is a really nice mod. what about the possiblly of going via the nav panel connectors instead of micro usb. this would as far as i know leave the usb port free and also not have the disadvantage of having a usb connector attached which can be easily damged.
Personalyu i wouldnt do this mod as i use my phone to tether a hell of a lot so it seems pointless to me, but being able to just sit your phone down and have it charge is awesome.
Great work!!!!
Click to expand...
Click to collapse
I tired the navpanel connections with no success. If anyone has a multimeter please try to do it to theirs (with charger plugged in).
that is really odd....only think i can think of is manye theres something that needs to happen with the middle pin.
nice work i think that decal are very cute indeed!
PPL this is knowed from a long time! This pins are used for example with Car Kit like CU s400: http://www.slashgear.com/htc-hd2-cu-s400-car-kit-gets-priced-detailed-coming-december-1360143/
This car kit is in two versions: like this on 1st photo - use other battery cover which use this "mysterious" pins to run NaviPanel and charging battery and 2nd version with charging via microUSB port.
I hope this helps a bit.
veda_sticks said:
that is really odd....only think i can think of is manye theres something that needs to happen with the middle pin.
Click to expand...
Click to collapse
This "odd" middle pin you can find in every phone battery too. If you depart any battery you can find there a little electronic circuit.
I think, that this pin is used to metering battery charge, but i can be wrong - im not advanced in electornics.
I'm well aware of the existance of these products but cannot figure out what the three contacts below the batteries are.
Maybe some users having one. In that case he/she can make photos of all connectors or better - check it with multimeter which connector is +, - and this middle one.
Maybe some service manuals can tell something more abt this. I searched for it and i did'nt find nothing useful.
FRANQ_23_PL said:
Maybe some users having one. In that case he/she can make photos of all connectors or better - check it with multimeter which connector is +, - and this middle one.
Maybe some service manuals can tell something more abt this. I searched for it and i did'nt find nothing useful.
Click to expand...
Click to collapse
I also did a search on google and xda but with no luck. I don't think it inputs 5v into the machine since I did shoot 5v into the 3 connectors using different combination.
Hi all,
The contact closest to the center of the phone (looking along the longest axis of the phone) is the +5V, the one furthest from the +5V is the ground, and there's a small voltage on the center contact, positive to ground. These +5V voltage shows up (on my phone) only when the mini-USB charger is plugged in.
I've got the +5V terminal of the Pre plate attached to the +5V contact on the phone, and the other one attached to the GND contact. Inductive charging works at 341ma (as measure by the hardware and read by BattClock) at maximum, which is probably not coincidentally also the limit set on USB charging, at least from my laptop.
I tried hooking the Touchstone up to a Apple ~1" cubed charger, didn't get any charge. I haven't read the USB power specifications, but according to the people at the Palm forums you have to have a USB spec power-capable charger to initialize the Touchstone, and the USB ICs signal this by connecting the two data lines. This can be approximated by clipping a USB cable and twisting the data lines together on the Touchstone side of the cable. This allowed the Apple charger to power the Touchstone.
The HTC stock charger works fine, as does an 800ma Verizon charger I had laying around. I tried hooking the Touchstone up to both a [email protected] switching charger and a 5V 8A supply, the Touchstone still charged at 341ma. I'm guessing this is software, firmware or hardware limited, just like the computer USB connection. I would speculate that if you shorted the middle pin to the ground pin, it might remove this restriction. Or fry your phone, I didn't try it.
There's a guy on the Pre forums who got the Touchstone to consume about 1.02A (http://forums.precentral.net/palm-p...b-adapters-touchstone-dock-2.html#post2020491) so the thing can, apparently transfer some power. I don't know how long it would last at those wattages, but I'm going to read a bit on the USB power spec and see if the 341ma limit can be lifted.
It's kind of nice to use the internal connector, because it leaves the microUSB port open. If anyone has any questions feel free to ask. With the relevant portion of the Pre cover stuck to the back of my phone, there are no wires out of the chassis and the added part doesn't add any considerable bulk to the phone. It protrudes less than the camera.
Anyways, hope this isn't a thread-jack or too long, but I figured it might help anyone that's going to take the time to do this.
Thanks to the community here.
Did you dremel and hotglue the plastic case to the metal case? Interweb highfive from me to you!
Can you post pictures of the inside wiring please?
I did. I basically cut out a square from the HD2 back large enough to hold the coiled length of wire that is needed to allow the back to be removed and articulated. Then I used Super Glue to fix the section of the Pre back containing the inductive coil and circuitry to the HD2 back.
If you're trying to maintain your warranty I might suggest DigiKey part number 478-4687-1-ND, it's from the AVX "MOBO Spring Contact Interconnect Solutions" catalog under battery connectors (I can send you a .pdf copy of the catalog, it's too big to upload to forum). This is a 3mm pitch connector that should mate well with the internal connector - but - I don't have calipers so I would measure before ordering. I just soldered the wires to my HD2.
I'll post some pictures soonish.
And yeah, high five for sure. Thanks for pioneering this. My last phone was retired when the power connector became flaky, so it's nice not to have to worry about the contact wearing out.
Ur mod is on a dutch popular website!
http://tweakers.net/nieuws/69360/mod-maakt-draadloos-laden-mogelijk-op-htc-hd2.html
Right angle micro-usb
I'm looking to do the same thing with my Vibrant and have been searching for a similar connector. I just did a quick google search and found these angled connectors:
http://www.usbfirewire.com/u_microb_cables_angled.html
I tried soldering it your way with no sucess
Soldering pins are as shown
(If viewing vertically with top up)
(leftside of hd2) negative x positive (center of hd2)
bumping an old thread to see if you've taken pictures of the contact points yet.
Sorry it took me so long to reply. Two pictures, the first is the terminal with the wires soldered in, the second shows how I got the cables from the Palm coil/board through the cover. The terminals as you look along the longest axis of the phone with the microUSB plug closest to you are GND, something, and +5v.
So from left to right: 1 GND / 2 ? / 3 +5v.
Ok guys, so nuclear war stroke the planet, your brand new tv and pc got busted in the initial attack and you're left with your precious HD2 running some custom rom and about 16-32gb of storage. Hope you don't get borred, there won't be many apps on marketplace, or even a marketplace (servers got busted by the nuke )
Now to get more seriously i can't figure out why i would need a phone able to be powered on 24/24. But i guess at least it could be useful on camping trips or stuff like this.
This is the start of a project, are goals are something like this:
1. reverse engineer the charge algorithm used by HD2 (in involves at least 2 charging modes each with 2 stages, as i know so far)
2. assemble or buy a 5-10W solar panel (only the panel and a Schottky type fast diode)
3. get myself some old laptop batteries and strip them down for cells and controllers.
4. design and assemble a cell pack as a buffer between the solar panel and phone
5. design a switching mode voltage stabilizer and make a custom usb hub in order to also have usb host functionality if i feel geeky and need linux
6. design a charge controller for the cell pack when using solar power.
7. put all things together and test
The goal is simple. Although there are solar batteries that provide some extra juice to laptops or pda's they function somewhat like 2-3 hours discharge, about one day in full sun to recharge.
I want a system that can power a full load working hd2 (worst scenario) non stop (day and night) including cloudy days, nuclear winter or whatever. The system must also be able to power about 3-4 usb devices and sustain a full 500mA drain on each port while still being able to power the hd2 non stop. Aaah, yes, the thing must be portable, plug&play, reliable and maintenance free. At most, it should have the size of a regular 15 inch laptop and about 2kg weight (all things included).
Stage 1 completed
So i figured out how hd2 charges it's battery. It's pretty simple actually.
Charging is made in the same way for either wall charger or usb charging. Same pins are used. However, when the wall charger is used, charging current can be as high as 800-900mA. This will decrease to some 20-30mA when the battery will be almost 100% charged.
If you however connect the usb data pins to hd2 and to something (computer, hub etc) hd2 will change the charging mode to usb. This feature ensures that when connected to a pc, the phone will never try to get 8-900mA from a 500mA usb port pretty neat. Instead, maximum charge current is limited to about 400mA.
If you get access to the usb wires inside the cable you can trigger either mode by simply disconnecting or reconnecting the data pins (green+white on standard usb cables). This is useful because i can devise some means of redirecting the charge current to either external battery (let's say after a night of use for the hd2) or to the hd2 if .. for some reason it's internal battery is discharged.
A usb enabled pic microcontroller (say 18f2550) can be used to control the charging process of either internal or external battery by simulating a pc connection, thus enabling hd2 to switch to low current charge. However if i'm guessing right, a simple usb hub could also do the job as it also contains a microcontoller that "knows" the usb protocol. So because i will use an external powered hub for linux, I'll try to use it also for switching between charging modes. Besides is more easier this way and i (or others) will be spared the time needed to program a microcontroller, or fabricate a pcb for it and it's corresponding components. And.. in case of nuclear attack there won't be any radio shack or electronics store where you could buy microcontrollers
Stage 2 completed:
Well i got myself some time ago a cheap 10watt polycrystaline solar panel for use with a robot i'm building. It was about $50 here in Romania. I guess i'll be using this one, even if it's quite big (something like a 16 inch laptop). Anyway i could also power other things with it. Will do some tests, and if it's suited for the job, it will be used. It arrived completely assembled so it also spares me the trouble and time of connecting individual cells into to form a solar panel.
Update : completed, will use the spare 10watt panel, until a new one arrives.
Stage 3 completed:
Got some 5-6 old laptop batteries. Stripped them down and got some ~30 cells. I'll test them out and sort about 4-6 of them.
Stage 4 completed: I'm currently sorting out some cells. As far as design goes, the capacity of the "extended battery" will be 14400mAh (single charge, using no solar power). That could easily power a full 15 inch laptop for about 4 hours, so i guess hd2 will have no problems staying alive for one night until next day and the sunrise to kick in for the solar charging to take place
Stage 5+6 completed:
There won't be any linear voltage stabilizer design for the buffer between the battery and hd2. They are quite inefficient with 30-40% power lost in the form of heat. Switching mode stabilizers+converters will be the way for this design. Found a ready made voltage stabilizer (converter) that's suited for the job , Saved some good hours that would otherwise have been spent on designing one from available parts.
Stage 7: yep, i'm now building the damn thing. I've simplified the design as much as i could, while keeping it safe for the phone, i guess the project will be possible to make by anyone with basic soldering skills.
apr. 13 - update: construction delayed due to one cell failure (the difference in internal resistance between the cells was greater then i expected). Will now search for a replacement, recalibrate the battery pack and recharge. However I expect that the battery module should be ready by the end of this day or tomorrow.
ok then.. it was built, it was tested and i'm already using it or at least.. trying to figure out a use for it
Anyway, if you're the camping type, if you feel geeky or wanna make a eco-friendly charger for the hd2 (or other usb charging enabled things) here's how to build one
You'll need the following materials:
- patience, this is a long post, try not to get bored while reading it
- some basic electronics skills, basic understanding of components, measurements and circuit troubleshooting (this is not a beginner project i guess, as hard as i tried to make it, if done improperly... well of course, you risk killing the poor phone in the process).
- some second hand laptop batteries, 3-4 would be ideal, they can be kind of old, but must be functional to some degree.
- a cheap usb charger used for cars, the one that plugs into the cigarette jack OR some good electronics skills to design a switching power supply. Guess most of people will go with the first option, in order to be more helpful i also designed this circuit using this option. You should buy the cheapest adapter, the cheaper the better. That's because the expensive ones have a feature that enables them to stop working if the voltage of the car battery drops to a certain point. That's supposed to be some sort of protection not to allow the car battery to discharge and thus preventing you to start your car. We don't want this protection, we want to be cheap asses, we want dirt cheap. However the adapter you want to buy must deliver 5V at around 1-1.5Amps minimum. 5Volts at 500mA is to little, it will simply kill itself when you start the thing once it's completed.
- a standard usb hub, any will do. This is if you want usb host functionality or use linux.
- a 5-10W solar panel. The bigger the better - it will allow to recharge the buffer battery (the one you'll be building) at a faster rate. This is the single most expensive part of this build. If you simply want an external battery for the hd2 you can skip the panel, if you want solar charging.. this is .. of course, a must.
- one fast rectifier diode or a schottky diode, you should buy it if you use a solar panel, the supplier of solar panel could also recommend one to use with that specific panel. We have to use one, this will make sure the current goes from the panel to the battery, not the other way around.
- bunch of wires, a multimeter and a soldering tool witch you're not afraid to use.
- a variable power supply, either it be a wall charger with variable output voltage, a laboratory power supply, or some charger that can output anywhere from 3.6 to 4.5 volts at anywhere from 300mA to 1A. Any combination will do. This is required only once in order to precharge the cells to a specific voltage.
- one switch or something similar in order to ... switch the thing on and off.
- spare time/understanding wife/coffee etc
1. Ok, first of all you need to get those laptop batteries open. Use some sharp tool, your karate skills or whatever necessary to crack those batteries open and expose the individual cells inside. Be careful not to damage the cells in the process, at least if you use some sharp tools. Once exposed, the cells will be linked to each other, you need to separate them by cutting the wires or metal bands that links them. Once done sort them out, if you have multiple batteries, sort the cells from each battery in a different case or basket or whatever you want, the idea is not to mix them.
Here's mine:
2. You now need to measure up individual cells with a multimeter. You're looking for the voltage rating of each cell. If you find cells with 0 volts, they're dead. If you place the multimeter in continuity testing mode and the 0 volts cells are showing continuity across their leads, yep.. they're really dead. Never use these. Good cells have anywhere from 1volt to 3-4volts.
Once you selected your good cells start forming a pack. The idea is simple. The more cells you put, the longer the thing will last. Standard laptop cells are rated to a minimum of 3.7Volts and 2400mAh. Each of them is almost double the capacity of the standard battery that comes with the HD2. However since you're going to use second-hand ones, they will have sign of usage, a smaller capacity then that of a new one. Still they will perform at least the same as hd2 battery in terms of battery life. Minimum configuration starts with 2 cells, i recommend 4 cells as a decent start but you can go and add more cells if you like. The more cells the longer battery life but at the expense of added weight. My choice was 6 cells. If you had 2 laptop batteries and each of them had 6 cells, you can make your pack on anywhere from 2 to 12 cells.
Let's say you choose 6 cells (always an even number). If 6 is you choice, you will need to divide that number by 2. So you get 3. You need 3 working cells from the same laptop battery to form a pair. Go back to the place you kept the cells and select 3 cells, NEVER mix cells from different batteries. These 3 cells you have (first pair) will need to be linked in parallel connection. The negative ( - ) of each cell is linked to the negative of the other and the positive to the other 2 cell's positive. We'll get there, but at a future step. Now we need the second pair of 3 cells. Again look in your cell basket and try to find 3 more cells from the same battery. This battery may be different then that first one you selected cells for the first pair. Yet again, the 3 cells must come from a single battery, no mixes. And.... again, these 3 cells must be placed in parallel. So if we already imagine them connected, we would have 2 pairs, each of them with 3 cells linked in parallel. The 2 pairs must be linked in series, so the minus of one pair will go to the plus (positive pins) of the other. The unconnected pins of each pairs (one minus one plus) will be used for voltage supply - you'll get the combined voltage of the cell pack here. If i were to draw this things for you to better understand.. it would look something like this.
green is one cell pair, orange the other. The black things are wires. This are the connections for a 6 cell pack. If you have 8 cells, you will make pairs from 4 cells (2 pairs). If you have 4 cells - the pairs will have 2 cells. A charged cell will have something like 4 volts. A pair made up of several cells in parallel will still have 4 volts across it's leads, but the overall current capacity of the pair is increased by the number of cells it contains. So if you have 3 cells each with 4v and 2200mAh, the pair will have 4 volts but with 6600mAh. If you place 2 pairs in series like on that drawing, you increase the voltage of the group by the number of pairs you add while still having the same current capacity. So if you get 2 pairs of 4 volts and 6600mAh, you will have 1 group, 8 volts and still 6600mAh. That's the total output of your pack. Because hd2 needs 5V (not 8 !!) we need something to decrease the voltage from 8 to 5 volts. That's why we need that car usb charger. It normally uses the 12V available at the cigarette jack to output 5v your phone can use. Cheaper ones, can use 8 volts, or 7 volts (lower voltages) because they don't have a circuit to prevent deep discharging the car battery like expensive one have. We need one without this circuit, because our battery pack only outputs 8V. So the car usb charger will take the 8 volts at it's input and give us 5volts at output.
3. before linking cells to each other, you need to charge them to the same voltage. Use a charger/power supply etc. I used a lab. variable power supply, if i had none, my weapon of choice would be a nokia standard wall charger (or another brand), older ones, i would cut off it's jack, expose the wires and connect them to my cells, it outputs 3.7 volts, enough to charge each cell. So charge each cell to about 3.7 volts. You will need to connect the multimeter in parallel to the cell and monitor the charging process. When a cell reaches 3.7 V disconnect it and charge another one, until all of them have 3.7 V. After this, leave the cells for one day. Next day you will be measuring each cell again. If one of them drops charge by it's own and you find.. let's say 3 V, you got a defective one, back to step 1&2 and select other cell pairs. If all cells still have the same aprox. level (somewhere around 3.5 to 3.7 volts) you're good to go.
Here's one cell linked to my voltage supply.
4. start thinking of either a case of something to contain your build. I used copper plated pcb (from electronics stores, radio shack etc). I will be connecting my cells to this thing, kind of like a pcb assembly. You may use some plastic housing and connect the cells with wires and secure them with some glue. If you have experience working with pcb, etching the copper layer and such things, feel free to try using pcb.
Here's my blank pcb for this job - i've already cut it to required dimensions. It's the orange metallic thing in the center. Beside it you can see my hub and the usb car adapter i will use.
5. disassemble (i repeat disassemble.. no more karate skills) your hub (if you're going to use one) and your car usb adapter. My usb adapter looks something like this.
The hub interior will look different, we'll get on that on a later step. Anyway, speaking of the usb car adapter, i'll be needing that small pcb with the components, so i'll remove it from there. The board contains the switching mode voltage converter, yummy yummy, i want that. It basically has 1 chip that generates a pulse signal that is feed to the input of a power transistor which pulses the input voltage across a coil. By autoinduction the coil produces another current, other components rectify and filter it so the second smaller current, produced by the coil, it's basically what powers on the devices connected at the output. In simple terms .. that's how it works. Again.. we need this, don't break it
Mine has a funny oval shaped form, so i'll be cutting my pcb in order to insert it inside.
There are 2 wires coming out of the small board inside. That's were the cigarette jack was connected. We will connect our cell pack to that, so you might wanna remember their position. The red one will be the positive one, black being negative. In a cigarette jack, the center pin is always positive, so if your wires have other colors, the one that's linked to the center pin will be the positive one.
6. Look for a way to place the cells inside your casing or on your pcb. Since i will do a pcb with them, i'm trying to find a possible placement for them.
this was one way, but i figured it was easier for me to simply place each pair on a line and form 2 single lines of cells instead of 3. Once done, i begun drawing the pcb with some paint marker. I will then etch the pcb, so only the paint covered areas will remain.
here's the pcb after etching, i'm connecting various wires to complete the cell pack circuit before connecting the cell themselves.
If you're using some sort of case, it's time to begin assembling your cells together. Use the solder gun or whatever you have for soldering to attach some wires to the each cell leads. Li-ion and heat aren't good friends, be as quick as possible when soldering, you don't want to heat up the cell too much. If it starts to make any strange noise, hiss or is venting anything from it... run away, don't touch it, don't throw it.. simply leave it and run away. Of course, this is a very rare scenario.. but take your safety when working with high reactivity materials like li-ion cells.
You want to arrange the cells in that paint draw up in the post. 2 pairs, linked in series. First solder wires to make one pair, then the other, then connect the pairs to each other. If you use a case, use some insulator to cover the solder points and to avoid some accidental short circuits in the future.
Back to my pcb solution, here's my assembly.
7. If you want to use an usb hub, you can try to salvage some usb port from an old pc or laptop's motherboard. This way you could avoid using a permanently attached wire to the device you're building in order to have the hub connected to the phone. I found an old laptop motherboard with an intact usb jack.
i remove the usb port from it and soldered on my board.
8. Next you need to connect the car usb charger's pcb to the battery pack you assembled. Basically the 2 wires from the charger must be linked with the 2 wires from the battery pack. Insert a switch on the cable in order to be able to turn on and off the whole thing. In my case, i'll now connect the car charger's pcb to my pcb, in the portion i've cut.
9. now you need to modify your hub to be able to power on hd2 during usb hosting mode. There's a link in the linux section (ubuntu for hd2) about this, you may want to read that also. I basically soldered a wire across each hub's usb port positive pin (the 4 usb jacks) and the input usb jack. The ground connection is the same for all jacks. So all jacks including the one used for connecting to a usb host device (pc) have the power pins linked together. Those 2 power pins must also be linked to the output of the usb car charger so that when you power up the thing using the switch, the charger also powers up the usb hub. After you solder all the wires, also insulate the soldering points and secure the hub in your casing along with the battery pack and usb car charger's pcb.
Here's mine, it was soldered on my pcb.
as you can see, there are some couple of wires coming out from it. Those need to be connected to the phone for me to have usb host functionality. So i'll connect these wires to the usb port i've mounted at step 7 so i can use a standard usb - microusb cable to link this thing to the phone. If you want to make it simpler, cut out a usb - microusb cable and directly solder the wires onto the hub's pcb as shown in the guide on the ubuntu linux thread for hd2.
In my case, i use that port i salvaged, as i said before.
10. assemble the whole thing and carefull inspect the connections. The order of this will be - battery pack - linked to the car usb charger - that's linked to the hub power pins (for each usb port). You'll then have one usb port for use when requiring usb host functionality, 4 usb ports for connecting all sort of usb slave devices, and one usb port (the one that it's soldered to the car usb charger) for use when you want to simply charge your device normally.
Here's my build. I've also placed a fuse between the battery and the usb charger, so that in case of malfunction it breaks the circuit. The fuse holding pin is the black thing at the opposite side of the usb hub. Near the pcb, you can see the fuse and it's cap.
11. Check again all connections. when ready, press the switch and bring the thing to life. Use the multimeter and check all usb ports voltage. You shoudn't have more then 5.5Volts and no less then 4.5Volts. If you do, then you did something wrong, turn off, disassemble and recheck. If you did it right, you'll get a voltage inside the above interval. Inspect the device once again and make sure all things are safely placed and secured inside. Try plugging some cheap usb devices you may have, a mouse, usb flashlight, another hub etc. If they receive power and all it's ok you may try to connect the phone.
Voila.. usb charging from the ghetto style external battery.
And here's a small video of preliminary testing (i haven't yet tested the usb hosting capability but i have no reason to think it will not work). At this time i didn't placed any switch on the board so i switch on and off the thing by placing the fuse inside the holder or removing it
http://www.youtube.com/watch?v=yf6kRpNNqkw
Next step... maybe some of you may think.. well how does this thing recharge when the batteries are depleted. At this stage the battery pack is recharged by connecting a 8.4 voltage supply across the battery pack leads (wires) but the next logical step will be adding the solar panel to the build and securing this pcb to the back of the panel. Then.. further testing. I'll be keeping the panel and that rectifier diode handy. This is still work in progress.
When are we getting it?
i guess it will take about 1-2 weeks to do the job.
i'm also involved in 2 more projects, it could be done as soon as i finish my automatic dog feeder with video-streaming over internet, food sensors and audio feedback. )
facdemol said:
i guess it will take about 1-2 weeks to do the job.
i'm also involved in 2 more projects, it could be done as soon as i finish my automatic dog feeder with video-streaming over internet, food sensors and audio feedback. )
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Click to collapse
Hey facdemol I am not as versed in electronics as you are my friend. So my question to you is this is something that someone with a fair level of intelligents can attempt also? Secound is this, is the list you give in your first post all some one needs to try this? I would really like try this myself and maybe correspond my findings with you. Also thank you totally of you ammazing knowledge filled posts here on XDA.
lol.... Im not sure how to respond to this
Cant wait to see how it turns out, best of luck
sounds interesting!
Good man, keep us updated however things turn out... you sound like someone who isn't afraid of experimenting with electronics for the thrill!
Sent from my Nexus One
Wow! Pretty interesting
Hey facdemol I thought you might like to check this article in the Portal out if you have not already. Looking forward to hearing back from you here on your project.
good article, was inspiring
stage 2 and 3 are completed. Now working to design a high performance dc-dc (switching mode) converter that would take 8.4V input and give me some 5V @ 2.5A output for hd2's charging and the usb hub. Some work needs to be done here and some careful testing, if for whatever reason this converter fails, hd2 motherboard could get fried Working on a way to implement some safeties, also i'm studying the way older pda's and pna's used switching mode power supply's and converters. I'm thinking i could either salvage one of these modules or build one specifically for hd2.
Update : found a way to make this pretty DIY for anyone with basic electronics skill (so that you can avoid designing switching mode converters, making PCB's, winding coils etc).
I found some dirt cheap car adapters that output 5v (pc usb jack) and can be used for various usb charging enabled devices. I'm testing to see their performance with my custom battery pack and the solar panel. Results are pretty good so far, i managed to run them stable at arout 5.5-6Volts input voltage. 2 of these will be required for this project (2 amp max current) or one if the output transistor inside is changed or a heatsink is mounted on it. I will come back with results and in the end, a guide with the required modifications.
The second post contains the updated progress on this project.
Third post will contain some sort of guide for a DIY assembly of such device.
These are updated daily.
If everything goes smooth, i guess i will posting some pictures and guides to build such things, by the end of this day or tomorrow.
Current features of this design :
- 10watt solar panel module
- 14400mAh battery module - cell pack designed as 3p2s
- 2 charge modes (slow - similar to a pc's usb port and fast - similar to hd's wall charger)
- 4 powered usb ports (usb host capable)
- 1 high-power usb port (it can charge any device requiring 5V at around 500mA - 1500mA)
- uses standard usb-microusb cables, no need for other hacks or special cables
- feels geeky
facdemol said:
The second post contains the updated progress on this project.
Third post will contain some sort of guide for a DIY assembly of such device.
These are updated daily.
If everything goes smooth, i guess i will posting some pictures and guides to build such things, by the end of this day or tomorrow.
Click to expand...
Click to collapse
Sounds greet I will bee waiting to see what you have come up with man, this could be something that can change how we can use our HD2s on the go. n
Keep up the good work facdemol, I am also waiting to see if you post any more power consumption results in your other thread.
I would like to ask anyone reading this to help vote this to be published in the XDA portal by clicking the vote bottom at the top right of the first post by facdemol, he deserves recognition for his great work with this project and his others.
Very Interesting ! Good luck with the project! will be following to see what develops!
I love this. Great concept.
it took a while to charge the independent cells to the same level and to form a pack. The charge alignment is a must, otherwise, the battery back will discharge at an uneven rate among each cell. One done properly it should allow the maximum battery life and no future maintenance.
I've done some testing on it, already hooked up the hd2 to this thing, it's working properly, both charging modes, usb host etc. I guess i'll come back today with the guide and pictures to make this, it took the better part of yesterday to manually charge/discharge each of the 6 cells in the pack.
updated post 3, half of the buid is already done and operational. The battery and hub+charger module needs to be linked up to the solar panel and some of case to be built.
There are some pics and one video with the thing working. Just basic testing for now, i just finished it.
Very interesting...great job mate...
I need an expert advice in choosing Samsung original charging back or this Qi receiver. I have gotten used to with NFC to toggle things and I need NFC to work. Right now I have NFC cards (Mifare smartcards) pasted at the back of my desk and I use it over the desk that is 2 cm thick. I don't even have to touch phone to the desk for NFC to work. I hover 5mm above and Tasker takes over (with one profile I copy files off network drive). With so much of automation, I cannot go back to NFC working sporadically or working when I have to physically touch the card.
I do not use protective cases as I want my phone looking slim and sexy. And I heard original wireless back cover is too thick. Please tell me how thick it is. And if you are using Qi receiver, please tell me if you can read tags through 2 cm thick wooden table.
And I found NCF compatible Qi receiver in Amazon (click here). I have a question to people who own original samsung wireless back cover - is there buffer space between back of the cover and battery for thermal insulation? It would justify additional thickness.
I wish someone checked temperature difference at the surface of the battery when using Qi coil vs original back cover.
Having used both, I can assure you that the OEM cover is best for NFC, and I don't even notice the extra thickness. I even prefer the look, as the camera no longer sticks out. It's the only solution that works adequately with my NFC activated BT adapters, and is much more forgiving about placement on the chargers.
---------- Post added at 09:34 AM ---------- Previous post was at 09:33 AM ----------
And... It's the only solution I've found with working tap to pay.
rcobourn said:
Having used both, I can assure you that the OEM cover is best for NFC, and I don't even notice the extra thickness. I even prefer the look, as the camera no longer sticks out. It's the only solution that works adequately with my NFC activated BT adapters, and is much more forgiving about placement on the chargers.
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Click to collapse
Thanks I ordered original wireless charging back.
Buy the original wireless charging back, at least that won't void your warranty if something goes wrong.
Anyone using the qi enabled s-view flip cover? I'm wondering if it's possible to charge the phone with qi when you have the flip cover open and put it on the back of the phone?
Would be nice if it worked as I would be able to use wireless charging in my car while running waze.