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1
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1answer
71 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
75 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
93 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
0answers
22 views

CDMA Chip Sequence Sending and Receiving [duplicate]

In CDMA, every user has a sort of signature (chip sequence number). When we apply the signature on the receiving signal, only the intended person's signal is extracted from the total signal. But my ...
0
votes
1answer
66 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
75 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
145 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?
0
votes
2answers
337 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
76 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
65 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 ...
0
votes
2answers
640 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
85 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
75 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
48 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 ...
0
votes
0answers
45 views

What to replace for tx9013 in a mobile charger circuit?

I am looking to implement an circuit called emergency mobile charger. Yes it converts 1.5V from a simple AA battery to a 5.1V output regulated by Zener diode. I am a bit confused that will the circuit ...
0
votes
1answer
65 views

Combining audio outputs once amplified

I'm familiar of course with the preferable way to mix audio, that is prior to amplification. However, I have a few mobile radios with roughly 1 watt audio outputs, which I would like to send their ...
0
votes
0answers
234 views

How can I isolate a short (in a mobile phone in this case)

I have a Nokia 6030 cell phone, and it's been serving me 7 years. It developed an interesting problem, which looks like a short of some kind: the battery drains very fast, for an hour or so, and the ...
-3
votes
1answer
942 views

How to make home automation using arduino for light, fan etc [closed]

How to make home automation step by step using arduino for light, fan to switch it on and off using mobile device. I m very interested in this project. Basically i know how to use arduino and ...
0
votes
1answer
77 views

Charge controller for Li-ion or Li-Polymer battery

I am trying to work out the good charger for Mobile phones, which can serve as good performer for various smart phones out there in market these days & mostly using Li-ion battery. Charging has 4 ...
4
votes
1answer
721 views

Can the NFC antenna of smart phone read signals from (active) RFID tags/transmitters

Can the NFC antenna of mobile phone such as the Galaxy S4 or iPhone in addition to their NFC functionality, also be used to read signals from (active) RFID tags/transmitters e.g. from 20ft away not ...
4
votes
5answers
731 views

Why are smartphones and tablets ARM based?

Why don't these devices use Intel processors like laptops do? Why are they restricted to ARM? Also for Windows 8, do they want ARM just for tablets and smartphones or is it also for laptops/desktops ...
4
votes
1answer
111 views

Solid reasons for switching off mobile devices on air planes [closed]

Recently a flight attendant forced me to shut down my tablet PC for the period of landing the air plane, despite wireless and bluetooth being in air plane mode already. Questions: Are there ...
-3
votes
1answer
66 views

i would like to build a sort of mobile [closed]

i would like to build a mobile phone pendent for my little sister it would only make calls and only to one number i know of one similar device to what i am looking for: the Burg 5 but i would ...
4
votes
2answers
284 views

“Wireless” USB cable, via RF / 3G

I'm looking into the feasibility of a project to develop a USB-over-RF device for physical penetration testing engagements. The idea is that our tester could connect a device to a USB port on a ...
2
votes
0answers
152 views

Does living near a cell tower decrease your overall exposure to RF? [closed]

I understand that my mobile phone will increase its RF levels when it struggles to connect with a cell tower/base station due to distance. Also being nearer a cell tower will increase my exposure to ...
0
votes
1answer
181 views

powering android phone from 3 AA battery directly (not USB!) [closed]

I have Sony Arc phone which was spoiled by me (story OutTopic) as it won't charge lion battery anymore. the phone itself works perfectly. I don't want to do the regular 3AA to USB charger way. Trying ...
-1
votes
4answers
2k views

difference between voice and data services?

What is the difference between the voice and date services. I have read that for voice services T1/E1 frame is used and for data services a frame with a standard header and payload nd tail is used ...
0
votes
3answers
122 views

Mobile AC Power Source for Projector?

I need to use a projector for a presentation (about 30 mins, but I'll need to make it about 3 times), but there will not be any wall outlets available. I thought about using an inverter and a 12/24v ...
2
votes
2answers
247 views

Using an old Bluetooth-enabled Blackberry as a GPS

I have a few Blackberry devices with integrated GPS functionality. Given that the SIM is no longer activated, is it possible to use this device as a second hand GPS unit? My thought is that I can ...
3
votes
2answers
101 views

Why do mobile phone transmissions come in pulses?

We are all familiar with the phenomenon that mobile phones induce in amplifiers and loudspeakers. The bip bip-da-bip bip-da-bip which happens just before you get a call, or if the phone is just ...
2
votes
4answers
3k views

Is it possible to make a usb charger to power multiple devices?

I was thinking how nice it would be to have a single wall plug with multiple (4-6) USB ports that would be capable of supplying enough power (at 5v) to charge say an iPad, smartphone, bluetooth ...
-4
votes
2answers
404 views

Bluetooth or Direct Mobile, which is more harmful to health? [closed]

Radiation derived from mobile is harmful to health, as I heard of it. So, is it more harmful than that of using mobile/cell phone with blue-tooth device?
3
votes
1answer
1k views

Locate a mobile phone precisely for indoors tracking

Firstly, I don't know if I'm asking this at the right place, so excuse me if it's not. Suppose i want to track a mobile phone in a local area, lets say a large hall of 200 m x 50 m, using any ...
-1
votes
1answer
1k views

Micro-B USB male to 2x Micro-B USB female Y splitter adapter [closed]

I'm looking for the above mentioned splitter. It's like this, but Micro-B USB and like this, but reverse the male/female. By the way, I was able to use my Samsung Galaxy S3 phone with the Samsung MHL ...
3
votes
1answer
1k views

Need formula to selecting coaxial cable type and GSM antenna

Need formula to selecting coaxial cable type and GSM antenna I'm using a GSM modem for my application which is often installed at a basement where there is no GSM signal so I will need to attach it ...
6
votes
1answer
3k views

How to make usb 3G modem signal stronger with aluminum foil antenna?

I'm in an area with weak signal reception, but I'd like to make my 3G connection better at very low cost. I heard using aluminum foil as reflecting surface and placing the modem in some way in front ...
1
vote
1answer
2k views

What is the pinout for HTC One X docks?

I used to have a Motorola Milestone which used magnets to detect car and desktop docks. I've now got an HTC One X and am looking for dock options. The standard ones look pretty expensive, but there ...
1
vote
4answers
2k views

What kind of SIM are these?

I have a device (XT107) that requires a SIM card. It takes a SIM card that have cobber plate (not sure what to call that) that supports all 8 curcuits on the device. When speaking with people, some ...
6
votes
3answers
5k views

Do 3G and phone calls(gsm) use the same antenna in a mobile phone?

When I disable "3G or EDGE" (cellular data) connection from my smart phone's settings, I can still make a phone call. Do phone calls and cellular data use different antennas and frequencies in a ...
1
vote
1answer
812 views

How can I build a FBus to USB cable?

Is it possible to make FBus to USB? Does it need any complex circuit?
-2
votes
1answer
317 views

Which chip in this image is the main CPU for the Samsung Galaxy 3

Which chip is the main CPU in this photo? The image was taken from there. Samsung Galaxy 3
15
votes
4answers
11k views

Why do many laptops run on 19 volts?

Typically mobile devices that have a mains-powered supply will accept voltage that is multiple of some single battery voltage. For example, 4.5 volts is 1.5 volts (AA primary battery) 3 times and 36 ...
0
votes
1answer
168 views

ARM Mini Mobile Device Development [duplicate]

Possible Duplicate: ARM Processor on a PCB I'm trying to build a mini device with 3 buttons (that will each preform a task) and it will have an ARM Processor, no screen or form of display, ...
3
votes
2answers
196 views

Any idea on any device which track multiple mobile phones

I'm currently ask to work on a project which I have never worked before. And I have no freaking idea or its not even in my area of expertice. Ususally I Google as everyone does. But what is the use ...
0
votes
1answer
240 views

Host (baseband) controller in mobile phone

Hi mobile world I met many times the term "host controller" or "baseband controller" used interchangeably in the context of being the heart of the mobile. What exaclty is that, som SoC with CPU, GPU, ...
2
votes
0answers
155 views

What is the usage of 3rd lead in mobile batteries [duplicate]

Possible Duplicate: Why we have 3 pins on some batteries? I'm trying to build (DIY) open charger for mobile battery. I would like to know what is the usage the middle one? Is there ...
2
votes
1answer
989 views

What Voltage/Current Levels Can I Send Into the Microphone Input on a Mobile Phone?

I have a device that is sending 9600baud using only Tx, Rx, and Gnd. I am not sure, but I think the voltage is either the 3v or 5v level. I want to receive that serial data on my mobile phone. I ...
1
vote
2answers
855 views

building an unlock system with bluetooth and mobile phone using arduino

I want to trigger the completion (connecting) of a circuit. I want to do this via bluetooth on mobile phone. Setup: User turns mobile app on User puts phone near bluetooth reciever connected to ...
1
vote
1answer
178 views

Scan for mobile phones?

I'd like to measure queuing time, similar to what they're doing in Finland. Instead of detecting bluetooth (which is disabled in most phones) I thought of detecting EDGE/3G. I'd like to log the ...
0
votes
1answer
436 views

Arduino Power On notebook PC

Is it possible to "Power On" notebook PC with Arduino (or with USB keyboard) without pressing notebooks power button ? Notebook PC is Acer 5720Z.