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-2
votes
2answers
78 views

Which chip remains on when the phone is switched off but it has to detect if the power button is pressed to switch it on?

I wanted to know which is the chip that runs to detect when the power button is pressed to switch on the phone. Is the real time clock and circuit and this chip connected in any way?
0
votes
1answer
45 views

External power supply a mobile phone

I have an alarm device. It convert 12v to 4,3V to the phone. It's outputs are 4.7V, GND, and two output to the phone buttons If the inputs loop of the alarm device is opened that means the wire have ...
1
vote
2answers
111 views

cell phone detector circuit

i have successfully implimented below circuit for active cell phone detection but i dont seem to understand the working of this circuit,if someone could explain it would be a great help.Thank you.
-3
votes
3answers
109 views

Commnication between mobiles which are in range of 100 meters without using any mobile tower for free [duplicate]

Every mobile radiates its signal to its nearest tower during phone call.Then is it possible for two mobiles to communicate with out using any tower with in range of 100 meters or more .If it is ...
4
votes
1answer
103 views

Getting started with Qualcomm reference designs

I am looking to get started with Qualcomm Reference Designs. I am partly inspired by this article: "Start Your Own Smartphone Company for $1,000". I have an application that I would like to be able ...
1
vote
1answer
33 views

Wifi uplink air interface

Most Wifi 802.11 standards use OFDM to achieve high data rates wirelessly. However, I was told OFDM is not suitable for uplink as it requires expensive and inefficient amplifiers which are not ...
0
votes
2answers
90 views

mobile phone direct power

I've got a few HTC Desire A8183's in which I would like to power directly off the wall socket. I've got a 12volt 1amp transformer which I've put through a voltage regulator to bring that down to the ...
0
votes
2answers
72 views

Bike mobile charger

Hi, I've made a battery operated mobile charger using this circuit. I am able to charge the basic phones (with 2100mAh battery) with it. But the problem is, I couldn't charge any smart phones ...
-1
votes
2answers
55 views

Effect of WiFi hotspot usage on mobile phone circuitry [closed]

Despite the fact that mobile phones come in wide a variaary and form different suppliers and with different software, most mobiles todays have a WiFi hotspot feature that can convert a mobiles' ...
0
votes
0answers
41 views

Detect connected Cellphone (USB) via Arduino

I have to detect a usb connected mobile phone via Arduino but still pass the data signal to another device. Now it works great if I just connect the USB directly to the Arduino and read the pull ...
2
votes
4answers
260 views

How does the mobile 3.5mm audio port work, and Can I light a LED from it?

I am trying to do this, light a LED from the headphone wire(mobile) but it seems it gives ac in there, I don't have much idea, please help.
1
vote
0answers
45 views

What is Virtual Array Antenna?

What is virtual array antenna (VAA)? I have searched it everywhere but i was unable to find direct answer to this question. I know this concept was built from phased array antenna. Please explain ...
0
votes
1answer
95 views

How is the output voltage of a mobile phone charger fixed to a rated value? [duplicate]

Here is the circuit of cellphone charger. I have seen the input voltage range for a cellphone charger to be 100-230 V but the output voltage to be fixed to the rated value(like ~4.5 V). So, my ...
0
votes
2answers
35 views

CDMA modulation syncronization

Related: How in CDMA mobiles receiver gets unique code to decode its respective signal? This question says that a cdma "channel" has a publicly known code associated with it. Ok. But, how is this ...
0
votes
1answer
112 views

Driving 4.2V TFT by 5V

I have a nooby question: Is it within the range of tolerance to drive a TFT (car electronics 4.3 inch low cost type) which runs on 4.2V internally (12V DCDC-converted to 4.2V by an 'XL1509 adjustable ...
0
votes
1answer
76 views

Mobile WIFI: how close can mobile devices be placed and still have a functional WIFI connection?

I wish to run a large array (50+) of hacked Android phones as a computing cluster. They will need to be networked so I plan to use their built-in WIFI radios to talk over a single WIFI network. (I ...
-2
votes
1answer
117 views

wireless device to send data with low latency up to 1km

I need a device about the size of a phone with 2 buttons, the device will be used to let a server know the outcome of an event (2 possible outcomes). A mobile phone app would be the obvious choice but ...
0
votes
2answers
4k views

Is BLE 4.1 backwards compatible to BLE 4.0 ? Can a phone with bluetooth 4.0 talk with a mote with BLE4.1?

BLE 4.1 is out and it could be considered the biggest news for internet of thing developers. I want to know if my mote with BLE 4.1 can interact with iPhone 6 which has Bluetooth 4.0.
3
votes
2answers
288 views

How Channelization code is shared in HSDPA?

I am on my way to understand the HSDPA/HSUPA technologies. I have just started and came upon the topic of channelization code. I learned how these codes are generated - Hadamard code technique - and ...
-1
votes
3answers
114 views

What happens when gadget gets 100% charged

We see that when our mobile phones, laptops, i-pads, or any other electronic gadget requiring charging, gets completely charged it starts displaying that it has stopped charging like in my HTC phone ...
2
votes
2answers
7k views

Is over charging the phone while using headset risky [closed]

I recently came across a post in social network which was claiming to be a news about a girl getting electrocuted during her sleep with her headsets connected to the mobile and the mobile being ...
-2
votes
1answer
94k views

Why does Samsung mobile phone batteries come with a chip-like paper? Are they spying on us? [closed]

Yesterday I saw a WhatsApp message. In that, one person is showing the Samsung phone batteries. He removes the wrapper and takes out the black color thin paper or plastic sheet which is attached with ...
0
votes
1answer
85 views

Makeshift way to drain a battery?

I have a 3.8V mobile-phone battery that I need to discharge. However I don't have any electrical components (say led) with me. What is a crude way to do this using household items?
2
votes
2answers
156 views

Modem to Modem via GPRS

I am working on a GPRS communication design. What I want to do to connects two modems together via GPRS. But I found that i could not connect. I was able to connect both modems to the internet using ...
0
votes
1answer
83 views

How can I link battery life to resistivity of a phone PCB?

Are there any equations/relevant explanations that can link resistivity of the "wiring"* (or other components) on a phone's PCB to its battery life, i.e. can I prove that using silver wires would ...
4
votes
2answers
107 views

why smartphones don't cause noise on the around speakers

Before the smartphones (or maybe before the some new tech) when a cell phone rings, the speakers around it made noises. Hovewer, nowadays they do not. Why? What changed?
0
votes
1answer
109 views

Why can current phones act as Wi-Fi routers, but not as mobile broadband (3G, 4G etc.) routers? [closed]

Many of today's smartphones enable users to share their own internet connection with others via Wi-Fi through tethering. However, from what I understand, current Wi-Fi has much shorter range and ...
0
votes
1answer
223 views

Sensors controlled by Mobile Phone

I have a project which is of very low costs. The management has at least agreed for a cheap Mobile set and a solenoid valves. They have also agreed for a few extra project budget. The solenoid valves ...
2
votes
1answer
118 views

Inherent exploitability and power state machines

I'm working on understanding power state machines in regard to mobile computing devices. Most of the information on this subject seems to stem from this article. It's not particularly important to the ...
2
votes
2answers
9k views

Which is used in mobile phones? A microprocessor or a microcontroller?

Please help me with this. I'm trying hard to get the specific answer. I want to know a particular answer. What we use in mobile phones? Micro-controller or microprocessor? Or both?
0
votes
2answers
410 views

mobile battery charging using voltage regulator?

Circuit shown at http://www.instructables.com/id/9v-USB-charger/ will that satisfy all condition of mobile charging through usb ? what is advantage of circuit shown at ...
0
votes
1answer
317 views

Can I connect directly a 3.7V 18650 li-ion battery to a mobile (cellphone)? [closed]

If I remove the 3.7V battery from my mobile, is it possible to connect to the battery +/- terminals a 3.7V li-ion 18650 battery?
0
votes
3answers
217 views

What's an easy approach to provide Wi-Fi/Webserver to mobile phone apps without hotspot

I'm a software programmer and I'm up to start a project of an embedded outdoor device which I will be able to control by any mobile phone. My preferred approach is having the embedded device provide ...
-1
votes
1answer
424 views

3.5mm headphone jack frequency range [closed]

I'm going to receive audio data from a device and handle through mobile's headphone jack. but my data has low frequency about 1Hz and depending what i found its too low for this port, I searched about ...
0
votes
1answer
70 views

What is the rate at which a mobile/cell phone listens for an incoming call or a text in standby mode? [closed]

As I understand, a mobile/cell phone, in the standby mode, listens to some kind of circular buffer in its memory for acquired packets from the antenna to check if there's something that regards ...
2
votes
1answer
931 views

How can I extend this circuit to use it in our real life?

I am planning to design a wireless mobile charger circuit next week. For that purpose, I have selected the circuit which is shown below and is collected from the post: wireless mobile battery charger. ...
1
vote
4answers
198 views

Do cells phones put out a signal when charged through data out?

Do cells phones put out a signal when fully charged through data out? I am wondering this because there is a competition to see who can build the best and most efficient portable cell phone battery ...
1
vote
1answer
1k views

Could anyone explain the two-ray ground-reflection model in plain English

I am studying about wireless communications and I need to understand the two-ray ground-reflection model for one of my assignments. However, I fail to understand it. Could anyone provide a ...
2
votes
1answer
131 views

What kind of solar panel is required to keep a mobile alive forever?

I want to build a webcam from an old mobile and I want it to be solar powered. The phone use a 3.7V lithium-ion battery of 1500mAh capacity. The phone last 24h hours on one charge. So if I'm right, ...
0
votes
1answer
475 views

Can I use a 7805 as a current regulator?

Can I use 7805 as current regulator? My input is 12-14 V DC (battery) and I require output 5V and 500mA or adjustable. My background is CS so unaware of these ICs. I have searched LM317 and LM338 but ...
0
votes
1answer
226 views

2 sources one speaker - for old rotary phone

I have built a "mobile" phone using an old GPO 746, a Raspberry Pi and an old Nokia 6301, amazingly I have managed to get the audio to/from the phone's 2.5mm jack plug to through the GPO handset, ...
-4
votes
1answer
104 views

Field trip to a home-based mobile phone factory [closed]

What are the components I need for assembling a hobby mobile phone? How would I go about assembling such a hobby device? Are there laws governing assembly/use of such hobby devices?
3
votes
3answers
635 views

How in CDMA mobiles receiver gets unique code to decode its respective signal?

Transmitted data in CDMA mobile is encoded with a random code. Receiver requires this random code to decode data from the received signal. From where the receiver will get this random code?
1
vote
2answers
17k views

Why does this mobile phone battery have 4 terminals? [duplicate]

Why do some mobile phone batteries have 4 terminals? I want to use a mobile phone battery for my project.
-3
votes
1answer
126 views

Do mobile phones lower their radiation if connected to WIFI [closed]

Suppose you have a phone you use for surfing, but the coverage is poor. As far as I know, that means it would have to increase its signal strength to max, quite possibly to a signal strength much ...
1
vote
1answer
344 views

12v socket not providing enough current for mobile phone? [closed]

I've just installed a 12v socket to my motorcycle. The socket has a sticker saying "12V - 1A", and the user manual says that "use is possible up to a power input rating of 12W". Taking that into ...
5
votes
4answers
12k views

How does the phone detect if 3.5 mm jack circuit is closed?

I have an android phone to which i have plugged an earphones. So at the top of the phone, I get the headphone symbol which indicates that the earphone is connected (In other words, the circuit at the ...
0
votes
1answer
166 views

Where can I buy a finished mobile camera module? [closed]

I am interested in buying a really small camera module for one of my projects. I know I can buy some iPhone/Samsung camera replacements on Ebay. But I have no information on their connectors and ...
0
votes
1answer
89 views

What is a Nokia FAID? [closed]

Nokia is a mobile phone brand, but what is an FAID? I tried searching but no definition came up. I'm guessing it's a security feature checked by the hardware in order to function properly.
2
votes
2answers
67 views

What replaces MobiTex for sporadic low bandwidth usage?

Back in the day I would use MobiTex for low bandwidth usage for devices that simply needed a few simple commands sent or received. It now seems next to impossible to procure or use MobiText devices ...