Boost mobile? - Page 25

keatonreckard · 06-06-2007, 04:38 PM

@purdoom

you say you need a serial cable to access gps features by a computer, would you then be able to use it with any generic gps software?

shotgunefx · 06-06-2007, 05:09 PM

Quote: Originally Posted by keatonreckard

@purdoom

you say you need a serial cable to access gps features by a computer, would you then be able to use it with any generic gps software?

Not sure, but I would think so as my phone as a GPS setting for NMEA out which is easily readable by many gps applications.

turbocad6 · 06-06-2007, 05:49 PM

ok, played a bit more with it, got my tools & cracked her open, the pads to solder to are pretty large & easy to solder to, I was able to solder to them with a big old butane iron & reassemble the phone & retain the functionality of the original power button on the keypad as well as have an external connection no problem...

the right value for the cap seems to be around 68uf, when I do 100uf it sometimes goes into flight mode, other times not, when I go low like 33uf it won't turn on, at the 68uf it auto turns on no problem....

well, there is a slight problem, but it should be pretty easy to solve, how the cap works is when it's discharged it initially looks like a short when it's connected to power, then when it get's charged, it is no longer shorted, so this momentary short is the equivelent of the button press, the different values determine the amount of time it takes to charge, which is why different values wil be different lengths of time buton is pressed, the 100uf is long enough that it is sometimes too long & puts it in flight mode....

the problem there is, once it's charged it's charged.. it takes a long time for it to drain that charge if just disconnected, so if you remove the power & reapply it, the cap is already charged, so it does no button press, I have to short the cap leads to discharge it, then it starts up the phone fine again upon applying power, the way around this will be to use a resistor in the circiut, this will need to be small enough to not trigger a closed circiut & be a shorted button, but large enough to drain the cap when power is removed, I need to get to radio shack & pick up an assortment to find the value that will work, but it should work no problem after that.... before you run out & get a 68uf cap, wait till I'm done, cause with the resistor in the mix that value could still change a bit possibly...

soooo, I'm almost there with the auto power on.... it should be a no problem thing once I get some resistors.... soory for the long drawn out explination, but I figured someone might want to know how this actually works

now, the phone uses a 3.6v battery, but I'm pretty sure that a common 3.3v supply should do the trick too, I have some 3.3v regulators that I'll play with, my goal is to power this straight from the cars 12v, so the battery won't be an issue at that point.... I think a day or 2 of this running off the car battery should't cause any problems, so the thing can stay on 24/7 which is my goal, if you park your car for a week at a time it may become an issue with battery drain, but using the car daily it should be fine... when I get it finished I'll measure power draw for a final determination there..., if your fine with just letting it run off the phone battery till it dies, then have it auto on upon car restart this will also work fine for that too... the issue there will be a short drive won't fully charge it, & then it'll last even less time when shut off that cycle

heres a few shots, the center pad for the button is also connected to that external square test pad, I was in a rush & I didn't easily find a pick up point for the outer ring somewhere else, so I just went to the outer ring of the button pad, no problem... I'm hacking my phone up & I'm not overly concerened with the cosmetics of it, so I just ran the wires out of the side, but if you stil want to use this as a portable phone it may be possible to do this internally or bring these connections out of the phone in a neater fashion.

once I get this all sorted, then I'll work on a way to have it periodicly restart the phone automatically too, that could be a little tricky while still keeping the power draw minimal though, I don't want to build a module for this that will use more power than the phone itself uses

shotgunefx · 06-06-2007, 06:04 PM

Quote: Originally Posted by turbocad6

ok, played a bit more with it, got my tools & cracked her open, the pads to solder to are pretty large & easy to solder to, I was able to solder to them with a big old butane iron & reassemble the phone & retain the functionality of the original power button on the keypad as well as have an external connection no problem...

the right value for the cap seems to be around 68uf, when I do 100uf it sometimes goes into flight mode, other times not, when I go low like 33uf it won't turn on, at the 68uf it auto turns on no problem....

well, there is a slight problem, but it should be pretty easy to solve, how the cap works is when it's discharged it initially looks like a short when it's connected to power, then when it get's charged, it is no longer shorted, so this momentary short is the equivelent of the button press, the different values determine the amount of time it takes to charge, which is why different values wil be different lengths of time buton is pressed, the 100uf is long enough that it is sometimes too long & puts it in flight mode....

the problem there is, once it's charged it's charged.. it takes a long time for it to drain that charge if just disconnected, so if you remove the power & reapply it, the cap is already charged, so it does no button press, I have to short the cap leads to discharge it, then it starts up the phone fine again upon applying power, the way around this will be to use a resistor in the circiut, this will need to be small enough to not trigger a closed circiut & be a shorted button, but large enough to drain the cap when power is removed, I need to get to radio shack & pick up an assortment to find the value that will work, but it should work no problem after that.... before you run out & get a 68uf cap, wait till I'm done, cause with the resistor in the mix that value could still change a bit possibly...

soooo, I'm almost there with the auto power on.... it should be a no problem thing once I get some resistors.... soory for the long drawn out explination, but I figured someone might want to know how this actually works

now, the phone uses a 3.6v battery, but I'm pretty sure that a common 3.3v supply should do the trick too, I have some 3.3v regulators that I'll play with, my goal is to power this straight from the cars 12v, so the battery won't be an issue at that point.... I think a day or 2 of this running off the car battery should't cause any problems, so the thing can stay on 24/7 which is my goal, if you park your car for a week at a time it may become an issue with battery drain, but using the car daily it should be fine... when I get it finished I'll measure power draw for a final determination there..., if your fine with just letting it run off the phone battery till it dies, then have it auto on upon car restart this will also work fine for that too... the issue there will be a short drive won't fully charge it, & then it'll last even less time when shut off that cycle

heres a few shots, the center pad for the button is also connected to that external square test pad, I was in a rush & I didn't easily find a pick up point for the outer ring somewhere else, so I just went to the outer ring of the button pad, no problem... I'm hacking my phone up & I'm not overly concerened with the cosmetics of it, so I just ran the wires out of the side, but if you stil want to use this as a portable phone it may be possible to do this internally or bring these connections out of the phone in a neater fashion.

once I get this all sorted, then I'll work on a way to have it periodicly restart the phone automatically too, that could be a little tricky while still keeping the power draw minimal though, I don't want to build a module for this that will use more power than the phone itself uses

Nice. Thanks for the pics. Have you tried an RC circuit calculator?

Like this? http://www.pronine.ca/rccir.htm

shotgunefx · 06-06-2007, 06:17 PM

Another possibility is to just use a small 8 pin pic with built in oscillator. If the phone is running at 3v+, should be relatively easy to power it. Then you could just have it go to sleep after powering on and it would draw uamps.

shotgunefx · 06-06-2007, 06:34 PM

Here's one that should work.

PIC10F220
http://www.microchip.com/stellent/id...cName=en023673

Around $0.40. Internal oscillator, selectable to 4 or 8 mhz. 8pin Dual inline package (if you had steady hands, you could get a tiny smd version and I'm sure it would fit easily inside the phone).

You'd just need to hook + to +, - to - and one of the output pins to the negative side of the power button.

The code itself would be trivial.

psuedo code
while (clockticks < desired clock ticks){
drive output pin to power button.
}
sleep.

Turning off the phone would retrigger the code to turn it on again.

turbocad6 · 06-06-2007, 08:23 PM

ok, I'm bit limited in what I can do personally with a pic, but I can talk to people who could do that end for me.. even with electronics, I'm no wiz by a long shot, but this simple stuff I can muddle through...

so I got my resistors & have played some more.. I got final values of 68uf cap with a 67k resistor, it auto powers the phone great, it works fine, the only slight issue is, when you remove power it takes 4.5 seconds for the cap to discharge.. so take away power, give power back 5 seconds or more later it starts up fine... for the way most of you guys want to use this it's fine, BUT if you interupt power for only like 1 second the phone will turn off & stay off.. I don't know how to get this much better & I think I have it about as optimised as I can with just a simple cap & resistor, I will research to see if theres a way to get this better that 4.5 seconds, although I guess a pic can delay the repowering on an auto restart for 5 seconds too, so realisticly I guess it's ok, but ? any ideas shotgun?

shotgunefx · 06-06-2007, 09:05 PM

Quote: Originally Posted by turbocad6

ok, I'm bit limited in what I can do personally with a pic, but I can talk to people who could do that end for me.. even with electronics, I'm no wiz by a long shot, but this simple stuff I can muddle through...

so I got my resistors & have played some more.. I got final values of 68uf cap with a 67k resistor, it auto powers the phone great, it works fine, the only slight issue is, when you remove power it takes 4.5 seconds for the cap to discharge.. so take away power, give power back 5 seconds or more later it starts up fine... for the way most of you guys want to use this it's fine, BUT if you interupt power for only like 1 second the phone will turn off & stay off.. I don't know how to get this much better & I think I have it about as optimised as I can with just a simple cap & resistor, I will research to see if theres a way to get this better that 4.5 seconds, although I guess a pic can delay the repowering on an auto restart for 5 seconds too, so realisticly I guess it's ok, but ? any ideas shotgun?

I'm better with digital than analog but...

I think the problem here is that when the power is interrupted for only a second, the cap still has most of it's charge and it sees it as a very brief button press so the phone ignores it. If I power down by hand, and tap the power button briefly, the same thing happens.

You could probably add a bleeder resistor and play with the values some more to get the discharge time down, a smaller cap will discharge quicker across it than a larger one. Unfortunately, the math required is not my strong point.

I'll have to look around, but I think all the pics I have on hand are at least 18pin. The reason I was thinking of a small pic was that I could actually maybe fit it inside the phone and have a component part of 1.

With the pic, you wouldn't need to wait 5 seconds as you wouldn't be using an rc circuit so there's no cap to discharge.

I haven't taken mine apart yet, do you know what the voltage is across the power button? 3.3v?

I'm going to have to take this thing apart soon and fiddle

turbocad6 · 06-06-2007, 09:17 PM

yeah, battery voltage across the power switch....

yeh, tht' definatey the problem, the cap takes a few seconds to discharge.. a smaller cap not enough & a larger resistor then it goes into flight mode... I tried a bunch of combinations & this is as good as I can get it up or down, I know that a pic can do the button press for me & then not need this circuit, but I was hoping to just do a momentary power loss & reinstate to keep it simpler

for the guy that just wants the phone to come on with a car start after the phone dies, this should work fine I think... I guess in the end I'll have the whole thing controlled with a pic

shotgunefx · 06-06-2007, 10:11 PM

Quote: Originally Posted by turbocad6

yeah, battery voltage across the power switch....

yeh, tht' definatey the problem, the cap takes a few seconds to discharge.. a smaller cap not enough & a larger resistor then it goes into flight mode... I tried a bunch of combinations & this is as good as I can get it up or down, I know that a pic can do the button press for me & then not need this circuit, but I was hoping to just do a momentary power loss & reinstate to keep it simpler

for the guy that just wants the phone to come on with a car start after the phone dies, this should work fine I think... I guess in the end I'll have the whole thing controlled with a pic

Any empty spots in the phone? I'd like to keep the mod internal if possible, but I suppose I could tape a little box on the back. I do want to keep it usable as is in an emergency.

Tweaking the rc circuit very well might get around the problem, though keep in mind, temp changes might cause problems as they effect resistance. Sure it's not a big deal in some places, but in the north, might be problematic from summer to winter.

turbocad6 · 06-06-2007, 11:17 PM

not much really, if you take the little vibrator out you could probably fit a tiny cap & resistor there maybe, the only other small amount of space that may be usable is inside the flip up screen nose, I wasn't really looking too hard cause this wasn't a consideration to me at the time, but it's pretty stuffed, smd components may work, when I dissasemble it again I'll show all the details,

what I'm thinking for myself is build it into the car, then maybe leave the headphone jack accessable so it can be used in an emergency that way. one issue I see here is the ribbon cables, they are close to impossible to extend without sending it out, so the main board will have to stay real close to the screen, I can work around this by having it right behind the screen & then duplicating the buttons by extending then off the main board, this can be extended as far as necissary without restrictions, so I can have the screen in my rearview mirror & have the button pad in my center console, sounds like a pain though, gotta see if button usage is even often enough to even warant that, I may just need 2 or 3 or 4 buttons on the edge of the mirror & only have to access the rear for all button access in an emergency only... still haven't seen how to load a recharge card to see if keyboard usage is very necissary there...