TLDR: careful about what aftermarket charger you plug your phone into. what parameters can software control in our phone?
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I was wondering if any of the Devs wanted to help inform me/others about what the USB charging issue is related to. In a recent post it sounded like Drew was getting into some code to help fix ZVH charging issues, but it fixed some, made some worse. This revived some questions I've had for a while.
I'm sorry if any of this is trivial or irrelevant, but i love knowing how things work, so anything you got would be appreciated.
1) does the device know what it is plugged into? how? i think my old evo used to go into "car mode" when plugged in to my car charger, "desktop mode" when plugged into a wall charger, and do usb storage/stuff when plugged into the computer. how did it know it was a wall charger vs car? can we do anything like this with our optimus?
2) why do phones charge faster on wall chargers than via the usb port or in a car? usb ports will limit current to 500mA but at that point the voltage will drop if the port is doing the limiting. so the device must have to be able to limit it's current consumption.
3) electrical engineer geek out: in the past i worried about plugging things into my car because it seemed that after i did the battery life would start to drop.
so this time around, i bought 3 different cheap chargers from meritline. i then connected a digital load which would first draw 50mA, then 500mA and cycle back and forth once a second. I looked at the voltages on an oscilliscope. One (which i got for $1) actually looked ok right out of the box. another looked decent, but one i had was not good at all.
The bad one had a lot of ringing in the signal, the voltage could spike up to nearly 6 volts. (2 volts P-P ripple on transitions). I was NOT going to plug my phone into this! I ended up adding a dampening circuit, and while I was in there, bumped the output voltage up a bit to 5.05 (1Amp), I may change it to 5.1V to match the wall charger, but I don't know if that will help at all. I had hoped this would charge my phone faster in my car, but doesn't appear to have made much difference.
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I was hoping that things i can measure and experiments i can do with physical hardware may be able to join with any dev's knowledge of software to solve ZVH charging issues and improve general charging performance.
I dont know if any of the issues relate to hardware at all and I hope I dont look like a fool in talking about things you've already all worked out. anyway, if you think i can help, feel free to ask.
------------
I was wondering if any of the Devs wanted to help inform me/others about what the USB charging issue is related to. In a recent post it sounded like Drew was getting into some code to help fix ZVH charging issues, but it fixed some, made some worse. This revived some questions I've had for a while.
I'm sorry if any of this is trivial or irrelevant, but i love knowing how things work, so anything you got would be appreciated.
1) does the device know what it is plugged into? how? i think my old evo used to go into "car mode" when plugged in to my car charger, "desktop mode" when plugged into a wall charger, and do usb storage/stuff when plugged into the computer. how did it know it was a wall charger vs car? can we do anything like this with our optimus?
2) why do phones charge faster on wall chargers than via the usb port or in a car? usb ports will limit current to 500mA but at that point the voltage will drop if the port is doing the limiting. so the device must have to be able to limit it's current consumption.
3) electrical engineer geek out: in the past i worried about plugging things into my car because it seemed that after i did the battery life would start to drop.
so this time around, i bought 3 different cheap chargers from meritline. i then connected a digital load which would first draw 50mA, then 500mA and cycle back and forth once a second. I looked at the voltages on an oscilliscope. One (which i got for $1) actually looked ok right out of the box. another looked decent, but one i had was not good at all.
The bad one had a lot of ringing in the signal, the voltage could spike up to nearly 6 volts. (2 volts P-P ripple on transitions). I was NOT going to plug my phone into this! I ended up adding a dampening circuit, and while I was in there, bumped the output voltage up a bit to 5.05 (1Amp), I may change it to 5.1V to match the wall charger, but I don't know if that will help at all. I had hoped this would charge my phone faster in my car, but doesn't appear to have made much difference.
---
I was hoping that things i can measure and experiments i can do with physical hardware may be able to join with any dev's knowledge of software to solve ZVH charging issues and improve general charging performance.
I dont know if any of the issues relate to hardware at all and I hope I dont look like a fool in talking about things you've already all worked out. anyway, if you think i can help, feel free to ask.
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