Questions tagged [communication]

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

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2answers
119 views

Calculate the data speed with clock rate

If the clock speed is 45.25MHz and I need 7 data cycles within that clock cycle, could someone show me the math to figure out the data speed frequency ?
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1answer
40 views

Confusion with serial communication standards when sending sync serial data to a PC thorugh its serial port

When I read about SSI communication I can see that a pair is used for clock and another pair is used for data transmission as follows: On the other hand if I read about RS422 all lines are data and ...
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1answer
81 views

Is NB-IoT roaming possible?

I found a comment on a blog post stating that NB-IoT doesn't support roaming: nbiot do not support roaming (you must have sim from the operator that have the infrastructure). nbiot also lacks support ...
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1answer
35 views

Is there a way to direct the data to a particular port for this scenario?

There is a PC program which reads ASCII data from serial port in real time and processes it. The thing is I'm not able to change the code. The program reads the incoming data where one can only set ...
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0answers
30 views

Impleminting Quasi orthogonal space time block code with feedback on Matlab

I was trying to implement Quasi orthogonal space time block code with feedback that presented here. The code matrix is shown as below: where k1 and k2 are feedback from reciever. the value of k1 and ...
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2answers
557 views

Modbus RTU using SoftwareSerial

Im trying to control a temperature controller using Arduino MEGA over SoftwareSerial. Im using Modbus-Master-Slave-for-Arduino library and I tried to test using example code below. It gives only <...
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0answers
96 views

Safe and feasible way to multiplex CAN bus?

Is there a standard method or tool to connect more than one CAN bus to a CAN controller with single CAN interface? Each CAN bus would be directly connected to individual transceivers and then the Tx,...
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0answers
30 views

Replace half-duplex electrical connection with light?

The digital pins of two Arduinos are connected for half duplex communication: Now I want to connect the electrical connection with optical communication through a light pipe: Drafts for separate ...
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5answers
6k views

Can I use I2C over 2m cables?

In my current project, I need to communicate between a microcontroller and some sensors over I2C. One of them is a temperature sensor, it needs to be placed at approximatively 2 meters far from the ...
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1answer
128 views

Help me choose the communication protocols that I need

I am developing an industrial sensor using a sensor IC and an ARM MCU which communicate via I2C. The data size is 3 bytes. Because the environment in which the sensor is located is harsh ( high ...
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1answer
57 views

High - Frequency Carrier Necessity

let's consider a basic scheme of a receiver. Now I have two questions: I was told that the presence of the mixer is important since it is useful to delete the carrier frequency of the received ...
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1answer
56 views

CDMA basic working principle

I find it hard to find on the internet a simplified explanation of the principle of operation of the CDMA system. Could you give me an example of how it works and how a receiver can correctly identify ...
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1answer
60 views

Shannon - Hartley Theorem

Let's consider the Shannon - Hartley formula for the channel capacity \$C\$: $$C = B \log_2 (1 + S/N)$$ I have two doubts about it: 1) is it correct for TDMA, FDMA, or CDMA? And why? 2) Can a ...
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1answer
63 views

Energy of a complex exponential signal

Noob question here. Why would the term \$j2\pi t\$ not have any effect on the energy of the signal?
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1answer
73 views

How to identify 422 or 485 bus from the PCB

I have a very old CPU card, maybe 1980's. It has following chips on it and most probably these are used for communication with the rest of the system. SN55188 Quad Line Drivers SNJ55189 Quad Line ...
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2answers
237 views

What does the prefix “+/-” indicate before the data line names?

At this link there are specs of a converter with the following excerpt: What does "+/-" sign indicate(mean) above before TxD or DATA? As far as I know TxD pin/line transmits and RxD receives the ...
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0answers
46 views

Two-way communication between esp32s

I am planning a circuit that requires two-way communication between one esp32 and 3 others. I want to use a master/slave architecture as shown here: They need to be able to communicated via hardware, ...
3
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2answers
187 views

Send and “read” a tone over the AC power lines

I would like to use this circuit to send a signal over the a live wire; Assuming the live wire on the right carry the signal; simulate this circuit – Schematic created using CircuitLab This ...
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1answer
203 views

What does Pass through I2C mean?

On page 3 of this app note the following is said Pass Through—This I 2C control enables communication with all the remote devices, whose device ID and corresponding device Alias fields is ...
0
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1answer
49 views

Telephone Call and Electromagnetic Waves [closed]

Can you give me a simple explanation of how do telephone calls work? I know that when I receive a telephone call, it means that my mobile has just received a certain Electromagnetic field. But in air ...
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3answers
201 views

How far can 3.3V UART go at 38400 baud?

I'm developing a set of boards that will all be listening to a single 3.3V 38400 baud UART (single TX device, my boards all listen to this line, no "RX" line). They are designed such that there are ...
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2answers
162 views

TCP data vs HTTP data over GSM modem

I am using M95 GSM Modem for remote data communication with the server. The server-end persons want me to use HTTP data connection. Another embedded guy has suggested to use sockets and TCP data for ...
0
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1answer
27 views

Data Lines on VME64 Bus

I am learning about the VME64 bus. It has only 16-bits of data bus on its P1 connector while no data pins on P2 connector. Does it means that VME64 is actually a 16-bit bus?
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1answer
40 views

Pins for VME64 Bus arbitration

I have a board that has VME64 core implemented in it and this board communicates with other boards via VME64 bus. All boards share the same backplane motherboard which has J1, J2 connectors on it. If ...
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1answer
30 views

Bare minimum pins for VME64 Bus

I have a board on which core for VME64 bus is implemented and it communicates with other boards on VME64 bus using only 1 connector (P1, 5 rows, 32 pins on each row, total 160 pins) instead of 2 ...
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2answers
105 views

Preventing audio feedback in an underwater multiway intercom

I'm trying to transmit data(bytes) from a speaker (out) to microphone (in) via an FM modulated link. Now I have the problem that both will be used simultaneously (full duplex) and next to each other (...
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0answers
55 views

Writing Flash Memory Serially

I am looking into writing data onto some Flash memory serially, the requirement is to replace the old parallel programmer with a serial based programmer example Cheetah SPI Host Adapter. The Flash ...
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0answers
20 views

Frequency Deviation is given by del (f) = KfAm (Kf= frequency modulation sensitivity and Am= Amplitude of Message signal)

Then why has it been divided by 2pi, as shown in the image. Really confused. Please help.
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1answer
57 views

Radiofrequency exposure from portable (vehicle-mounted) satellite uplink antennas

I came across these broadcasting vans recently in London. The antenna that's deployed I think is a Vislink Advent uplink antenna, similar to this model, designed to transmit to satellites for ...
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2answers
89 views

Lack of 'determinism' in Ethernet bus

While reading this website, I found out tha there is lack of 'determinism' in the Ethernet network bus as compared to some other buses like 1553. What I understand is that Ethernet is a single master ...
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2answers
83 views

Is there a method to get the carrier from the recieved QPSK signal?

If we have given a signal and we know that is a modulated QPSK signal, can we recover the carrier if we know the carrier frequency fc. Edit: A clarification, I do not have to do it in hardware, a ...
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0answers
43 views

what's up with u-law companding when u is 0

https://www.tutorialspoint.com/principles_of_communication/principles_of_communication_modulation_techniques.htm It says that I can get the compressed output of a signal using this: it also says ...
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1answer
103 views

What is the difference between residual phase noise and absolute phase noise?

Studying the characteristics of an oscillator with a phase noise analyzer, but I don't quite understand the difference between absolute and residual noise. Any help would be greatly appreciated
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0answers
67 views

Foster - Seeley FM Demodulator Explanation

Consider this Foster Seeley Demodulator If I have correctly understood, its basic working principle is the fact that at the secondary coils (L2) of the Balun there will be two signals equal and ...
0
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2answers
79 views

Can we band pass filter QPSK signal?

Consider we have QPSK signal with carrier frequency 10kHz. Generally, we demodulate or use matched filter on the the QPSK signal and recover the transmitted bit or the symbols. If the QPSk signal is ...
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1answer
57 views

How can line code polarity inversion happen?

One of the disadvantages of some line codes like NRZ-L or RZ is that if a sudden change in polarity occurs, then all received bits will be erroneous (flipped). How can such a sudden change in ...
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2answers
107 views

Measure voltage on 48 batteries at once using microcontroller

I am looking to design a microcontroller that can measure the voltages on 48 batteries. Some of the batteries will have floating voltages as the device is wired in a parallel string of 8 columns, with ...
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1answer
76 views

MCP2561/2562 CANbus voltage?

The datasheet says the MCP2561/MCP2562 is suitable for 12V and 24V systems except that everywhere I look in the datasheet it says VDD needs to be between 4.5 to 5V. How can CANH be greater than VDD or ...
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2answers
129 views

Extremely low data rate transmission over long distance for attinys

For a lighting project I need to be able to trigger 20 units every couple of seconds independently which are daisy chained with 1-2 m space between each of them like so: Control station ====== Unit 1 ...
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0answers
43 views

Are magnetically tunable surface acoustic wave devices commercially produced?

I have been reading up on studies of magnetically tunable surface acoustic wave devices, in general they note the relative velocity change or in some cases a frequency shift if it is part of an ...
0
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1answer
100 views

What chips can be used to design an Anti-Counterfeit /Authentication circuit? [closed]

I am an intern within the R&D branch of a company that designs tools that must operate with low noise at extremely high external temperatures (upwards of 175C). My boss asked that I look into ...
0
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1answer
76 views

Can I use a Ku band satellite dish for Wi-Fi?

Satellite TV works at 18-24Ghz and WiFi at 2.4Ghz, will a T.V dish antenna work for WiFi? Diameter of the dish is about 60-90cm
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1answer
80 views

Digital transmission of composite video [closed]

As the tittle suggest, I was thinking about making a wireless composite video transmission between a small camera (such as those sold for flying fpv) and a receiver. The two main specs it must have is ...
0
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1answer
70 views

Communication between device for 5 meters and low speeds

I need to make a communication between only two devices with a distance of 5 meters, which are connected by a cable of 4x2.5mm² (see in the image), being 1 wire for GND and wire for 12v, that would ...
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3answers
234 views

Does data rate increase with channel frequency?

It is commonly said that a higher channel frequency implies a higher data rate. For example, in https://www.howtogeek.com/222249/whats-the-difference-between-2.4-ghz-and-5-ghz-wi-fi-and-which-should-...
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1answer
137 views

How to calculate the 3dB point?

I understand this until the final two lines. How does he get from 27.8766 to 1149.8hz and 7224.7rad/s?
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1answer
93 views

Bluetooth vs BT Beacon [closed]

While trying to understand how BT devices work I came across another related term "BT Beacon". Is it same as BT communication or if a device is termed as BT beacon then it would have some specific ...
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1answer
50 views

I/O expanders- CAN & I2C

Currently in my system we use 16 I/O expanders with I2C interface. I want to change it to CAN interface. Which is the best possible way without compromising the cost? I tried searching for 16I/O ...
2
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0answers
33 views

Implications of using a 2C-#18 twisted shield pair nec type cmr cable for RS-485

The cable will be passing modbus and another equal cable will be used for loadshare. The total cable distance will be about 100ft. Its catalog number E2032S. I notice other threads related to CAT5, ...
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0answers
36 views

Bluetooth Mesh Module

So I would like to design a device that allows me to send instructions to different devices (each containing a HC-06 Module). I would like to ask if it would be ideal to use a Bluetooth Mesh? This is ...

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