Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [cellphone]

Questions regarding cellphones, or cellular devices. Please note that repair questions are often closed for failing to follow the Scope of the Site as described in the FAQ.

1
vote
2answers
74 views

Identify that connector - Is it reusable?

I have an Asus Zenfone AR which has had the screen replaced 3 times. Last time I replaced it myself, Asus the first 2 times. Screen replacement went fine but once together I discovered up volume ...
0
votes
2answers
75 views

Security/safety circuits in removable cell phone batteries?

It seems like the aftermarket phone battery is so flooded with terrible counterfeits it can't be too hard to trick a phone into thinking a battery is genuine. I'd really like to learn how to use an ...
0
votes
1answer
74 views

Google Pixel XL; Anyone know what this middle piece is called and what it does? [closed]

Does anyone know what this middle piece is called in the Google Pixel XL? Here is the image (I've underlined in blue): I noticed that it emits infrared light. I think its a proximity sensor but I ...
0
votes
0answers
42 views

GSM antenna connection from the phone does not make sense

I recently came across a phone (Samsung Galaxy Grand Prime SM-G530f) with trouble getting any network signal, I did some troubleshooting and ended up finding out that one of the pin(the GSM pin) to ...
0
votes
1answer
64 views

Is it possible to generate user-defined signal using an android phone?

Is it possible to generate an electronic wave signal using an android phone? (Theorically) For example by customizing the firmware can I produce some signals like \$ f(t)=2 \sin 3.2×10^9t+3\cos 5×10^...
6
votes
1answer
122 views

“Leeching” clock information from cell towers

I understand that cell base stations transmit very accurate time signals among other things. Do you need a SIM card and an account to receive this information, or is it something you can "leech" with ...
1
vote
1answer
150 views

How can a phone transmit the signal back to tower? [closed]

If cellphones have such a low power transmitter (around 200mW for LTE) and also doesn't have directionality then how can they talk back to the tower even though they are so powerful and built ...
0
votes
1answer
73 views

How can I power a USB cord from a 12v 2a power supply?

I'm new to the forums and have a problem I cannot find an answer to. I am making a lamp with LED strips inside powered by a 12v 2a power supply. I want to also power a USB cord with this power ...
-2
votes
1answer
119 views

How does cellphone idle time work?

Imagine a basic cell phone which operates in only 2G network and able to provide voice call & SMS service. Does this cell phone transmit any data to BTS in idle time (that is when the cell phone ...
0
votes
2answers
126 views

What's the hardware and software detect mechanism of the cellphone Micro USB devices attached and detached?

What's the hardware and software detect mechanism of the Android cellphone Micro USB devices attached and detached? simulate this circuit – Schematic created using CircuitLab Hardware ...
3
votes
1answer
57 views

Does Quick Charge have an effect on battery lifespan?

When charging my phone (a Samsung Galaxy Note 4 using a 3,220mAh lithium-ion battery) I have the option of charging it with with a standard charger or a Quick Charge 3.0 charger. Quick Charge is a: ...
0
votes
0answers
53 views

Android Phone Voltage Drop with DIY DC UPS

i'm currently developing some kind of an IoT with an android smartphone. it's going to be mounted fix on the wall with some enclosure. and i'm using phone's microUSB port for an USB OTG so i power the ...
0
votes
1answer
39 views

Direct Phone Charge from Solar Cells via USB

I have a 19V 0.7A series of solar cells I'd like to connect to a standard 5V USB breakout PCB for phone charging. Do I need to worry about causing damage to the phone or battery without a regulator? ...
0
votes
1answer
79 views

Fast charging ports under the hood - technical details behind the standards? [closed]

There are a few things I noticed and examined for two different fast charging standards: MediaTek PumpExpress works without any data communications with the charger. Output 2 from my USB multimeter ...
21
votes
6answers
2k views

What drives the advancement towards ever faster cellular network speeds? [closed]

I've always accepted that technology advances. Being born in the 90s, everything just becomes faster, smaller, cheaper and generally better if you wait a few years. This was most obvious with consumer ...
0
votes
1answer
98 views

Can a 3.2V, 400mAh battery charge a smartphone?

I have a solar panel that slowly charges this battery and I am thinking of trying to make a cell phone charger out of it. I know it won't be fast, but will it be able to charge a phone?
-3
votes
3answers
122 views

What technology is used for authorities to send emergency alerts to mobile phone users? [closed]

Do modern-day protocols that our mobile phones run on eg. CDMA/GSM, 3G or 4G have a emergency break-in/broadcast protocol for authorities to issue warnings to the public? In the recent case in Hawaii ...
-3
votes
1answer
69 views

Is it possible to move an internal SD card from a Samsung Galaxy S3 into another phone (Galaxy S2) to retrieve the information from the card? [closed]

Is it possible to move an internal SD card from a Samsung Galaxy S3 into another phone (Galaxy S2) to retrieve the information from the card, or is there any other way to access the information from ...
0
votes
2answers
95 views

Multiple induction coils in series (phone charging)

I'm doing a DIY project of sorts, and I'm trying to create an array of about sixteen coils in series in a sort of square. The goal of this is to make a larger charging surface than just a small pad, ...
1
vote
1answer
321 views

How hot does a lithium-ion phone battery have to be before it explodes?

I have an LG G4, model LG-H810 (serial indicates it's one of the shoddy-soldering ones) and it gets extremely hot during light gaming or while watching videos. It's not too uncommon for me to pick it ...
0
votes
0answers
30 views

How to tell if a phone is connected via usb?

I am creating a mobile solar phone charger with sun tracking. I have an LCD that outputs information about the system. I want to display if the phone is connected via USB to the system. Right now, I ...
0
votes
2answers
1k views

Identify which bus, mobile phone batteries use?

Mobile phone battery bus are usually 3 pin or 4 pin which are usually 2 wire buses (I2C) or a similar type of serial interface for a 1 wire bus. Does anyone know of a method for checking which bus ...
0
votes
1answer
112 views

How to remove folded battery from phone without starting a fire?

I was trying to replace the battery in my phone, but since it was very well glued to the phone, I accidentally folded it in half. This immediately caused some dark brown smoke to come out from it, so ...
1
vote
2answers
53 views

How are higher dimensional sphere packings used in signal transmission?

How are higher dimensional sphere packings (HDSPs) related to the error-correcting codes used by cell phones, space probes and the Internet for signal communication through noisy channels? HDSPs ...
0
votes
3answers
40 views

Velocity limit of UMTS and (or) CDMA2000

If the client is moving relative to the base station, the Doppler shift would compress or extend the packet. If the effect is strong enough, the PN generator in the receiver will eventually get out of ...
-2
votes
1answer
45 views

Ghost screen in the background…like water mark in my cell phone screen [closed]

I'm using Moto G4 plus bought during Feb'17.I have been noting this problem for a few weeks.If I stay long in a screen for eg. a chess game, the screen stays on all the following screens in the ...
-1
votes
1answer
62 views

Why sometimes I have voice but no data on a GSM network? [closed]

From what I understand, both voice and data are using the same antenna (At least 3G). Sometimes in a remote area, I have plenty of signal but no data service. Is it possible some cell towers don't ...
0
votes
1answer
127 views

What is a phone unlock box? [closed]

I have read about a phone unlock boxes (JAF, Phoenix, etc). What are they exactly? Some serial adapters? JTAG adapters? What is their role and what makes them so expensive?
1
vote
2answers
83 views

Powering multiple cellphones with a DC power supply

I have about 100 cheap cell phones that need to be on 24 hours a day. Unfortunately (likely due to the cheap nature of these phones) the batteries end up bloating after a couple months of being ...
1
vote
1answer
316 views

Polar pattern of typical speakers and microphones found in smartphones

I'm interested in knowing how is the directivity of the typical microphones and loudspeakers found in smartphones and tablets affected as they operate in the near ultrasound region (18-21 kHz). Near ...
0
votes
0answers
71 views

Can cell phones be reprogrammed for peer-to-peer connectivity avoiding carrier base stations to create a free meshed network? [duplicate]

In light of recent events concerning the freedom of internet, thoughts are going in the direction of breaking free from the control of wired internet service providers. One widely discussed option is ...
1
vote
2answers
634 views

Can a person suffer mild electrocution if he answers a charging phone with wet hands or sweaty palms? [closed]

This texas girl got electrocuted and died while using her cellphone in the bathtub. Can a person with wet hands or sweaty palms face mild electrocution if he answers the phone while it is being ...
0
votes
1answer
146 views

Phone charging problem with vehicle power adapter [closed]

Let's compare 2 situations: My smartphone is totally discharged. I plug a standard phone charger (standard 5V adapter, with micro-USB, wall adapter), then the battery increases of, say, 1% percent ...
4
votes
4answers
293 views

Why modern cellphones do not have an externally visible antenna?

Old phones had either a fixed antenna inside a housing which was externally visible, or a retractable antenna, which was visible when used. I'm assuming this was needed to obtain a certain total ...
-1
votes
1answer
68 views

Can cellphone magnetic holders affect the CPU?

My concern is mostly related to the various IC components such as CPU. I know that one of the problems of miniaturization is that electons jump to neighbouring lanes. Given how tight things are in an ...
0
votes
1answer
72 views

Could sliding down a slide damage my camera? [closed]

Specifically one of those plastic spiral slides - I was at the playground with my children yesterday and when we went down the slide there was enough static generated to stick our hair on end. Of ...
-3
votes
1answer
70 views

Damage a phone from intermittent charging? [closed]

Is it possible to damage a phone by charging it with an intermittent power source? For example, by using piezoelectric transducers in the soles of your shoes. Assuming they're wired to a 5V ...
1
vote
1answer
978 views

Is it safe to use RFID in a phone case

I looked into this and found only vague indications that it should be no problem, but nothing specific enough to feel safe. Based on reading this question and its answers and comments it seems like ...
0
votes
1answer
85 views

Using “Video 90” spray to clean up a cell phone motherboard

Can I use Video 90 Spray with electronic motherboards, like smartphones? My cell phone was dropped in water while the battery was out, now I have dried it out using rice and instant oat! Before, ...
0
votes
1answer
87 views

Why services that need to receive a signal, like Bluetooth or GPS, drain cell-phone battery?

The title is self-explanative. This is an emprically contrasted fact for cell phones, although I don't know why this happens. As far as my understanding goes the signal receiver is a passive ...
1
vote
2answers
128 views

Tracing a mobile phone's location without GPS [closed]

Without GPS, one way to locate a phone could be through trilateration. However, this would require the phone to be connected to 3 (or maybe even 4?) base stations to accurately obtain the phone's ...
59
votes
6answers
10k views

What makes smartphones tilt-sensitive? Will they retain this ability in zero-gravity conditions?

Most smartphones are tilt-sensitive, but what device makes this possible? Additionally, how does it (and the sensors associated with it) work? Also, since the working of these sensors seem, almost ...
2
votes
3answers
2k views

Why do cell phones sometimes interfere with amplifiers

I have an old Sony amplifier (TA-F117R) next to my desk where I keep my cell phone. Sometimes I put it ontop the amplifier, because it is pervecly alighed with the surface. When I hang some call up ...
4
votes
1answer
424 views

Implications of 2G network demise for basic (SMS/USSD) device communication

I'd like to know if basic GSM functionality will be affected by the phasing out of the 2G networks. I have several devices with modules like SIM900, old 2G Enfora, etc. and they use SMS and USSD for ...
13
votes
2answers
3k views

Why do only high-end phones support a lot of LTE bands?

Most lower and middle end phone only support 3/4 LTE bands. High end phones, like the iPhone, or flagships from Samsung and LG also support a lot of bands. iPhone 7: 1, 2, 3, 4, 5, 7, 8, 12, 13, 17, ...
-1
votes
2answers
7k views

how much power is radiated by cell towers?

I want to know how much power is radiated by cell towers of GSM (1.8 Ghz), 3G (2.1 Ghz), 4G (2.6 Ghz) ? I want links to references if exist.
0
votes
3answers
405 views

2.5mm Audio jack to micro USB [closed]

First of all, just a caveat: I am a complete newbie with electronics, computer software is more my thing! I have bought a (used) car this morning and it came with an old TrafficMaster Satnav ...
1
vote
4answers
416 views

Is it better to keep LiOn battery charge on the lows or the highs for battery lifespan? [closed]

I know that neither keeping battery full or discharged is good for battery life, but I want to know a basic answer: which one of the two bad alternatives is better? Full or empty. This is given that ...
0
votes
0answers
87 views

Is there a way to be able to conclusively detect/find a cellphone signal jammer?

I hope this is the right place to ask this. I'm going through a dispute with my employer and I'm being threatened with termination (we are both preparing for a legal battle). A day later I get no ...
0
votes
0answers
416 views

Use a Zener diode to turn on a transistor?

I am building a circuit that charges a mobile phone. I am using the IC Chip MP1583DN that has been configured to give a nice 5.30v out. i want to add protection so only a maximum Vout voltage does ...