Questions tagged [communication]

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

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368 views

CRC hardware implementation

What is the difference between these two implementations as the feedback is in first implementation the last reg only but the second implementation last reg xored with the input bit, so, what is the ...
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2answers
474 views

VHDL: Receiving Data from Terminal to FPGA using TTL

(I posted same question in stackoverflow but didn't get right answer) I'm newbie in VHDL. So today, after UART Tx, I tried to read Datas that coming from Realterm terminal. I only wrote Rx codes to ...
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1answer
65 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 ...
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1answer
45 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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37 views

Need help in computing the evolution of symbol error rate for uncoded OOK scheme over fading channels

I am trying to reproduce the results exhibited in Fig. 1. in the reference, i.e., "Error performance of coded FSO links in turbulent atmosphere modeled by gamma-gamma distributions" linked to (https://...
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3answers
139 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
196 views

S/N Formula with probability

Hello I am looking for the S/N formula that incorporates the probability of catching the signal, and setting an arbitrary treshold level above which we detect the signal. I can't figure out the ...
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1answer
86 views

Receive serial data on multiple pins ATTINY85 [closed]

I am working on a project in which multiple ATTINY's need to send numerical data between each other. In most cases the ATTINY will have to receive multiple streams of data on different pins. See the ...
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1answer
106 views

How do I stop signal looping with I/O port in this communication system

I am still a student. When I am designing communication system I am facing this problem: As shown in the figure I need to communicate with Master and Slave. But Master and Slave have single I/O port ...
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1answer
108 views

power and signal inside shielded CAT5 cable

I'll use a shielded CAT5 cable for RS485 line. The simplified bus structure is drawn in the picture . I have 130 slaves and their isolated part of RS485 IC is supplied from the supply placed at master....
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2answers
56 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 ...
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0answers
152 views

Why is there no reponse from ModbusRTU slave using converter?

There are two devices: Eaton EM20/M (~like Northern Design Cube 400) Volison ADM-5850G Connected them like: Trying to get data from EM20/M which supports ...
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80 views

May I know what kind of communication protocol is this?

signal video Power unit communicate with display unit of a Panasonic Washing Machine. Green one is clock signal 120hz PWM 85% duty cycle Purple one is signal from Master(Power unit) to Slave(...
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34 views

Connecting an industrial PLC to Android phone over a wire

Building an Android app that will take a picture and based on pixel values determine whether to continue operation or not (output true or false) to the PLC. It is a Mitsubishi FX3U-48 PLC and I don'...
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1answer
124 views

How to configure my xbee s2c modules for communicating with arduinos + sensors?

I have two xbee module (fixed on a development board), these boards does not have a individual access pins to access xbee pins (photo included), but rather a RS232 port. As for what I have searched, ...
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1answer
23 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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3answers
140 views

SPI/I2C chip, CS# pin pullip for I2C operations

I have a question regarding all sensors offering to work in either SPI or I2C mode. I am having some issues working with a MPU9250, but think it is a general question: When working in I2C, the MPU ...
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1answer
31 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
22 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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1answer
94 views

Communication between two Bluetooth devices [closed]

My supplier tells me that communication between 2 bluetooth devices requires authentication by an app. When reading online I believe it should be possible, but am not 100% sure. One article from EDN ...
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2answers
59 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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42 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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3answers
204 views

Industry standard ways of connecting boards / modules? [closed]

There are literally thousands of different types of connectors when I'm searching on a distributor such as element14, and I'm not sure what are the "standard" ways of connecting boards together. ...
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3answers
167 views

How to transfer data via UART that is read form another module using SPO at a faster rate?

I'm using a VS1053,to do a PCM recording for 1 minute by using STM32l4 microcontroller. The data is read from the VS1053 at 16 MHz, the sampling rate is 8000 sps and each sample is 2 bytes, which ...
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17 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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5answers
3k views

USB to TTL communication problem

I'm trying to connect a device to my laptop using a TTL to USB converter like this one but it doesn't works so I tried the following configuration (USB to Serial, RS232 to TTL and then to the ...
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1answer
48 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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1answer
117 views

Can we transmit a PSK modulated signal with YARD Stick One?

We are working on a project to produce a simple walkie talkie repeater. We have a RTL SDR, which we are using to reverse engineer our signal. Using this + URH, we think our signal is PSK modulated, ...
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2answers
141 views

Decay rate of Filter and how it relates to transmission speed

I had a question with regards to the decay rate of filters and how it responds to transmission speed. Suppose we have implemented a simple BFSK system with two asynchronous receivers and we have a ...
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2answers
116 views

Setting up a 485 network

I have a problem where my 485 transceiver just get damaged at field, when it's at laboratory everything runs fine, now reading about it I saw that 485 requires a 120Ohm impedance on both ends and bias ...
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2answers
78 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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2answers
74 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
111 views

AM modulation circuit modification

I have an assignment on AM modulation. I implemented a circuit and the output wasn't exactly correct, the output is not symmetrical about the x-axis. I'll post screenshots which might explain the ...
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0answers
33 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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2answers
250 views

Noise resilient, hot-pluggable communication bus over long cables?

I'm working on a setup, where we need communication between a master device and several slave microcontrollers distributed out in different boxes connected by "long" cat5e cables (3-10 meters) The ...
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1answer
38 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
1
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1answer
164 views

How to interpret this CAN bus data and find an equation?

I am trying to reverse engineer the data sent from an old CAN bus data logger. It sends a single ID which is selectable from a dip switch. The only bit of data I am struggling with is the RPM I plan ...
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2answers
2k views

Which RJ45 pins should I use for power supply?

I'm somewhere in a process of creating mini automation system for hobby use. I've already put CAT 5e cables with RJ-45 connectors in walls. They are somewhere between 5 - 30 meters long. On one side ...
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1answer
189 views

SPI read error with MCP2515

In an attempt to interface a motor controller, battery management system and maximum power point tracking device on a CAN bus, I used the MCP2515 and TJA1050 CAN breakout board. All these devices send ...
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0answers
22 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 ...
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1answer
313 views

Bandwidth-Noise-SNR relationship

Let’s say we have the noise figure F of a system of devices. We also have the bandwidth improvement coefficient ( as defined by my teacher ) $$BI=10log(\frac{B_{in}}{B_{out}})$$ where B1 is the ...
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2answers
69 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
136 views

ETSI[Europe] Regulations for 2.4Ghz ISM Bandwidth Limit and RF Power

I am trying to interface my STM32 with NRF24[2.4 Ghz ] or TI CC2500[2.4 Ghz] models. I am finding issue regarding maximum allowable Bandwidth and RF power set by ETSI[Europe] EN 300 328 and EN 300 440(...
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1answer
41 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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1answer
8k views

LIN-communication between two STM32F4 with a standard LIN-transceiver (Hello World)

I have the following circuit connecting two stm32F4 via the SN65HVDA195-Q1 LIN-transciever. simulate this circuit – ...
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0answers
25 views

NB-IoT/CAT-M1: Llimitation to the actively connected devices

For the new Cellular IoT technologies NB-IoT and CAT-M1, is there a limitation to the number of modems that can be connected to the base station at one time? I tried searching for this but I couldn't ...
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2answers
101 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
33 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
105 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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1answer
865 views

How does modulation technique affect channel capacity?

Shannon's channel capacity formula does not consider modulation techniques. How then does LTE achieve high data rate using advanced modulation techniques? P.S: I am novice in RF and signal processing....