Exchange of information between devices. Communication can be wired or wireless.

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22 views

GSM Modem will not register to network

after getting two modems (dev boards) Siemens TC35 and SIM900A I cannot get them to send sms. From the research it seems that somehow sim cards will not register to network. I bought three sim cards ...
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0answers
20 views

ADS1278 double values

I am recently using a ADS1278 as the ADC of my system. The configuration is Frame-sync, TDM, Fixed for the 8 channels. The mode is high speed (sampling at 64KSPS). The core clock and the serial clock ...
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0answers
45 views

Can I (re-)use USB data lines after charger detection?

I'm looking to add the Texas Instruments BQ24253 battery charger to my hardware design and to connect it a micro-usb receptacle. Does BC1.2 Compatible D+, D– Detection mean I can no longer use ...
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1answer
28 views

Using CP antenna for receiving and LP for transmitting

I've set up two antennas with Linear Polarization (LP) in both sides, in 2.4 GHz no more than 4 meters each other, but they are facing strongly obstruction object (like a big steel wall in they line ...
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3answers
87 views

Sending data from 4 transmitters to 1 receiver without a microcontroller

I am working on a project to wirelessly check whether any of four switches are pressed and I don't want to use a microcontroller on the transmitter side. I have worked with the cheap 434MHz HT12E/D ...
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0answers
41 views

Sub-1 GHz Narrow Band vs Wide Band

As per the TI document I came across which compares narrow band sub-1 usage vs wide band sub-1 usage mentions a concept called coding gain and its disadvantages. Because of my lack of understanding ...
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1answer
37 views

How to find out Packet Loss in a Broadcasting environment

Indeed packet loss is an important metric to use when comparing different communication protocols. To me it is understandable how one would computer Packet Loss in a unicast transmission. Simply the ...
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1answer
29 views

Bayas and total probability theorem?

The answer to this question is \$0.9^4 = 0.6561\$. But what if the transmission probability are not the same, such as \$0.95\$ for correctly receiving a \$0\$ and \$0.995\$ for correctly receiving a ...
2
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1answer
100 views

Capturing data at 500MHz

I have an ADC sampling at 500MHz (It is collecting data from an Ultrasound sensor). I need to be able to stream this data to my PC (for the time being - this will be done through a wireless unit). I ...
2
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1answer
50 views

Can Cellphones/ be used for Ad Hoc Communication?

Can Cell Phones be (legally) used Adhoc, (ie, Point-to-Point) Communication? For example, let's say I'm in a remote area of the woods, or a valley. Can I configure cell phones to be used as true ...
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0answers
12 views

Error expectation for channel estimation

I would like to compute the expectation of MSE error in channel estimation. I am using a pilot-aided channel estimation, however in my case, I am using the signals that pilots and data are already ...
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1answer
30 views

Probability of receiving a fixed bit sequence in a binary symmetric channel

What is the probability of receiving 1111 irrespective of what was transmitted? \$0.1^4 + 0.9^4 = 0.6562 \$ I am not sure about my answer because I think in my ...
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1answer
113 views

How does a low power device make a direct uplink to iridium satellite?

I was always fascinated by this idea. You are literally able to communicate or open a web browser from anywhere in the world. I am OK with the low power device able to receive data from satellites, ...
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2answers
43 views

Why there is no high voltage repeater / voltage translator ic (like max232) for I2C

why I2C don't work don't work with long wire, for UART we have 10 volt translators like max232, for I2C why there is no high voltage repeater ic?
14
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3answers
3k views

How can over 24 GHz communication be possible?

I read the article Google wants the US' wireless spectrum for balloon-based Internet. It says to use over 24 GHz frequency spectrum for communication. Is it ever possible to generate that high ...
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3answers
54 views

Is a multiplexed signal same as a composite signal?

Used to StackOverflow, this is my first question here. So please bear with me if the question is too simple and obvious to you as I am not good in Electrical Engineering stuff. I really need to ...
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1answer
30 views

Does the noisy-channel coding theorem (Shannon's theorem) apply to two-way communication with retransmission requests?

Does the noisy-channel coding theorem apply to automatic repeat request systems? Some people seem to imply that, when a system has 2-way communication, such systems can have far lower error rates at ...
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3answers
66 views

error correction code

Is there any technique which can detect and correct all error bits. To my knowledge 100% error correction is not possible but is there any technique that possibly exists? And can hamming code correct ...
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2answers
69 views

Power-line communication to household!

Most households in this planet have multiple 'wires' - one for plain electrical power, one for telephone, one for internet and one for cable TV (there may be more). I had heard of PLC ...
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2answers
58 views

Does a regular signal booster with antenna work for cell phone?

I am not that much familiar with communication and antennas. I want to build a gsm repeater (gsm signal booster), but I am not sure if it works if I do it like the way we do for a radio. What I am ...
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1answer
102 views

Read the instrument data from printer port directly with computer

I could not find the step by step guide of some kind to accomplish what I am planning to do. I have two devices that I want to connect to PC (windows). Right now, both devices write their output ...
4
votes
2answers
81 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?
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1answer
63 views

Find autocorrelation function of a signal

Find auto-correlation function of a signal $$g(t)=e^{-2t}\cdot u(t)$$ where \$u(t)\$ is the unit step function. I don't know how to start to solve this problem. My book list this equation only: ...
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1answer
113 views

How to programm a standalone MSP430g2553 via a com port?

The MSP430 is a dirt cheap MCU and i thought that if i could make a barebone launchpad out of that which can be programed directly via the PC COM port or a virtual one. So is it possible to program it ...
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2answers
53 views

Controlling a simple RC vehicle at long dinstace from a PC

I would like to control a simple, ground-based vehicle wirelessly, at ranges up to 5-6 km. The communication would be bi-directional (to get a feedback of "command received") but would only require ...
0
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1answer
56 views

Why is there a guard band in ADSL

I recently learned about ADSL and its modulation method DMT. I know the frequency spectrum is split up into a number of orthoganally spaced bins: Voice(PSTN) - Guard Band - Upstream - Downstream ...
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0answers
49 views

Why is asynchronous NAND negatively affected by compressed data in SSD benchmarks

Over the last year, the Kingston V300 SSD received lots of flack for having good benchmark scores but poor real world performance. PC building enthusiasts point the gun to Kingston's benchmark tool ...
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1answer
97 views

How to Calculate maximum distance between transmitter and receiver in wireless communication

how to calculate maximum distance between transmitter and receiver in free space radio communication by having transmitted power, antenna gain and noise-to-signal ratio ?
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1answer
74 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
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2answers
64 views

Wired communication from 1 atmel to many nodes

Right now i am looking for a better way to communicate to our wired nodes in a project that we are working on. Currently there is 1 main node that all other nodes talk to that in turn handles all ...
0
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1answer
80 views

How to interface with credit card terminals?

I am considering doing a project that involves a machine that can accept credit card payment automatically from customers. Think of it as a vending machine, that accept credit card. I want to ...
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2answers
81 views

Is it allowed to stop and restore I2C transmission?

Is it allowed to stop and restore I2C transmission? I would like to stop it in different periods of transmission and then after for example 500ms restore it to the state when it was stopped. I'm ...
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0answers
31 views

Minimum Shift Keying (In-phase, Quadrature Components derivation)

In the derivation of the minimum shift keying in-phase and quadrature components in Simon-Haykin Communication Systems 4th ed (p.387-390) we start off with the definition of the signal to be \$\ s(t) ...
4
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2answers
78 views

Why does timing change in dataframe using Manchester encoding

I have successfully received a couple data frames from an RF transmitter. I compared couple consecutive frames and the timing deviation between them is marginal, so I am convinced it is reasonably ...
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1answer
181 views

Simple Two wire SPI communication between two PIC24s

I am trying to achieve a simple SPI communication of 16-bit data from a PIC24FJ64GA002 to another of the same microcontroller. By following the data sheet to the word, I wrote the transmitter and ...
2
votes
3answers
341 views

How to read a push-pull output

I recently came across a sensor that had a "push-pull" output. I can't find anywhere how to read such an output: Is it some particular kind of analog output? I would want to read it with the ...
0
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1answer
34 views

Comparison of data transfer between different bandwidths

Which of the following can transfer more data [bps] 10Hz bandwidth over 2s 20Hz bandwidth over 1s It looks like its the same bps but I'm not sure.
0
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0answers
144 views

Passing sensor data from Arduino Uno R3 to android with USB Serial

I would like to know how would it look like to receive data on Android from DHT11 sensor which is connected to Arduino Uno R3 via USB Serial? I was trying some code examples for Arduino but i got a ...
1
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1answer
106 views

PIC to PIC serial communication

I need to send all port info from one pic to another using serial port.. currently using 9600bps baud rate. on pic18f4550 running at 20mhz clock. i have used this code to send and receive data of a ...
0
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1answer
52 views

GSM ZTE MG2639 module freezes after checking SIM

I'm communicating with my ZTE MG2639 module through UART. Few seconds after powering it and getting +CPIN and +STKPCI it just turns off (goes to stand by mode) It only happens with SIM card, and ...
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2answers
90 views

Differential Manchester Encoding

I am trying to understand Differential Manchester Encoding. The way I understand it is that the representation depends on the previous bit. If the previous bit was 0 there is a transition, but if it ...
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0answers
51 views

Amplitude modulation circuit explanation

I am currently doing an amplitude modulation experiment and I am using the following circuit: I need to know the effect of the various components regards to amplitude modulation. And also what is ...
0
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0answers
19 views

Will grid tie inverter and powerline communications affect each other

Since grid tie inverters "conform" their power to match the frequencies of a home, would powerline computer communications such as this router be affected by or affect a grid tie inverter?
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2answers
114 views

What is the exact difference between SGMII and 1000Base-X?

I was wondering what the exact difference between SGMII and 1000Base-X is, because both seem very similar. Is the "big" difference only the physical medium they are supposed to be transmitted on? Both ...
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2answers
100 views

Long Range Arduino Water Monitoring

I'm looking for advice on how I should setup a long range irrigation monitoring system using multiple Arduino boards. I would like advice/options available on what hardware I require to achieve my ...
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3answers
215 views

How does the automatic garage door opener know which button I've pushed on the wall control panel?

The wired wall control panel in my garage has only 2 wires connected to it. Yet somehow it acts different when I push the big "door" button than when I push the "light" button or the "lock" button. ...
3
votes
3answers
306 views

High Altitude Balloon Communication

Our team is planning to make a HAB (High Altitude Ballon) project for our university. We are planning to use XBee pro 868 RF modules (we are in Europe so we can not use 900 MHz band). We have to ...
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1answer
70 views

What is data rate? [closed]

What is the definition of data rate? What is the unit of it? Is it related to successful bits?
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1answer
72 views

40% Channel Utilization on 1Mb Satellite

Using the Slide Window technique, consider a satellite channel with: 500 byte frames sends 270 ms delay on send and receive 1 Mbps rate communication protocol is Sliding-windows Ignore the length ...
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2answers
83 views

How does a teleprinter work?

How in detail does a teleprinter system work? I am aware that many teleprinter used the Baudot code to relate alpha-numeric symbols to a sequence of 5 bits. What is the mechanical means by which a ...