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Questions tagged [communication]

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

4
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199 views

Home made passive tablet pen

I have an old wacom tablet at home, its really big and I'd like to use it but I've lost the pen for it. It uses pens with passive LC circuitry. The board creats an EM-field (I can see it on my ...
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0answers
30 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, ...
2
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0answers
1k views

ASDA-A2 RS-485 Communication Configuration

First of all, I know that my question is very specific for those who have hands on experience with the ASDA-A2 Servo Drive from Delta-Electronics. But I hope that someone will guide me through the ...
2
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0answers
43 views

How to pick a Balun and transformer for this power line measurement circuit

I was reading this paper here about measuring power line impedance using a network analyzer. It has a little circuit that they used but of course they're not nice enough to include a BOM :) How ...
2
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0answers
969 views

What is bit-true implementation

What is bit-true implementation (with an example if possible)? I was reading a paper and it was stated "a bit-true implementation of the algorithm on a FPGA was performed." So what exactly is bit-...
2
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0answers
556 views

Which serial protocol or encoding scheme does this scoreboard use?

I am trying to decode a signal stream coming from a Nevco scoreboard controller: Packets like this are sent every ~2.7 ms. I suspect it is some sort of UART signal because it is on the RX line of a ...
2
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0answers
3k views

why is shadow fading also called slow fading and large-scale fading?

I've encountered several similar claims regarding shadow fading on several books, and have some difficulty understanding them. (1) Shadow fading is called slow fading because the duration of the fade ...
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0answers
39 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 ...
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0answers
43 views

What effect do R5,R6,R7,R8 have on the following DSBSC Modulator?

I know that the first 741 essentially adds m(t) and c(t).The gain should be 1 so why do we have 3.9kohms resistance ? What use is it ? The second 741 circuit is a band pass filter . I think there is a ...
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0answers
57 views

Demodulation of a 38 kHz IR PWM signal

I want to learn how to demodulate a 38 kHz IR PWM signal.(Such as that transmitted by a TV Remote Control) I know it can be demodulated easily using a TSOP1738 IR receiver. I realize that the ...
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0answers
50 views

a tricky question regarding CDMA with 4 stations

i have encountered this tricky questions that left me really confused, would really appreciate your insight regarding it: given a cellular system with four stations that utilizes CDMA. given the ...
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0answers
31 views

Communication Theory - Determine efficiency of this protocol

My solution: I have no idea if what I did is correct. I'm getting a bit confused differentiating between 500 frames/minute and the 4.8Gb/s, they both seem like transmission rates to me. I'm assuming ...
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207 views

Honeywell I2C RH Sensor SDA line experiencing fluctuation between Vdd and Vdd/2

I had a problem when implementing I2C communication between NXP Kinetis K50 micro-controller and Honeywell Humidlcon I2C RH sensor. The RH sensor doesn't acknowledge when receiving the default address ...
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0answers
30 views

ENC28J60 rejects unicast packets - unicast filter is on, MAC is set, and addresses match

I'm programming an ENC28J60 driver at the moment, and have encountered something odd when attempting to receive packets. More specifically, unicast packets. According to the datasheet, when the ...
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0answers
69 views

How does the data rate of a CAN bus affect the value of the capacitor used in a split termination scheme?

I'm helping to redesign the CAN bus of an electric car, and we're interested in achieving higher data rates of up to 8 Mbit/s. We have a transceiver selected, a CMC to reduce inductively coupled ...
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0answers
196 views

Circuit to drive a telegraph sounder?

I acquired an old telegraph sounder, marked Western Electric 140 Ohms, and have a Morse code key. What voltage should I drive the sounder with to hear the proper Morse code click sounds when keyed? ...
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0answers
139 views

How to network hundreds of sensors over a serial connection?

So I'm looking for a way to connect hundreds (300-400) sensors (like an accelerometer) together over a serial connection to a micro-controller. The sensors would transmit about 500kbps each. I've ...
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0answers
37 views

Sources of online broadband RF energy data stream?

I am interested in finding recordings of broadband FM radio emissions, ideally in the marine VHF frequencies (156.0 and 162.025), in order to understand carrier artifacts and distortions that could ...
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0answers
66 views

Compressed single-sideband modulation?

I've had an idea for a new form of SSB modulation, using half-angle formulas as a basis for compressing the sideband of a SSB voice transmission. However, this idea seems so simple that I feel it must ...
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0answers
71 views

Computing the received signal

My question may seem a little bit easy but I'm new to these concepts and was hoping if you could help me clarify them by answering my questions. The received signal at the detector writes: $$ y = h x ...
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0answers
488 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 ...
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0answers
341 views

How to reduce SPI bit errors between a Bus Pirate and a BIOS chip?

I need to eliminate bit errors when reading a BIOS chip using a Bus Pirate v3.6. The BIOS chip is still soldered onto the motherboard. I'm using a Bus Pirate probe set to connect the Bus Pirate to a ...
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0answers
120 views

USB signal analysis

I have a device that I want to control it has window software that runs it, and a complex interface. I just need a pair of commands, also I know very little about usb device hacking, and signal ...
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0answers
52 views

Compression and communication power consumption trade-offs

Let's say I'd like to save battery power consumption when sending data to remote devices connected wirelessly, i.e., sensor networks. One of the ideas may be compressing the data to reduce the number ...
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0answers
183 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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0answers
85 views

Definition of “hot” resistor when calculating RMS thermal voltage?

I am calculating the RMS thermal noise voltage of a "hot" resistor of a tutorial sheet for uni. I have used the standard Johnson–Nyquist formulas, but the answer sheet does not include the entire ...
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0answers
785 views

PCIe card powered but not recognized on custom interface

I have a black magic declink mini recorder card that I am trying to recognize on a small form factor linux machine (debian 3.2.46-1 x86_64). I have made a custom interface board with what I think are ...
1
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0answers
564 views

MIMO with directional antennas

In the context of a competition, I need to set up a wireless link between a base station and a mobile target. The mobile target: -> will always be within the same 180 degree cone from the base ...
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0answers
481 views

Arduino to Serial Cable Encoding Error

I am trying to send data between an Arduino Uno and a Mac. The Arduino Uno is running this simple sketch to print data to serial: ...
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0answers
1k views

Communicate through a VPN link using Arduino Uart WiFi Module

Following describes the configuration of the system and other details. The problem is mentioned after that. If the initial description is too much or not needed, please skip it. I have a VPN (between ...
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0answers
646 views

Connecting 2 Arduinos with Bluetooth

I have been looking on Google for a project that involves 2 Arduinos communicating with Bluetooth. The only examples I can find are with an Arduino to an Android phone. Does anyone have links to let ...
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0answers
897 views

PIC32 read feedback from UART

I'm using a PIC32MX795F512H to set up a Roving RN-131 wifi module using UART. I can communicate with the device but I want some feedback whether my commands are processed or not. I basically need to ...
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0answers
10 views

Xbee Router in API mode not sending frames from UART input?

My current system is setup as follows: MCU ------ Xbee A(Router) ------ Xbee B(Coordinator) Xbee A is a router in API mode, Xbee B is a coordinator in API mode. MCU is MSP430, Xbee modules are ZB ...
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0answers
13 views

Average and maximal number of time slots in adaptive tree walk protocol

I was wondering if it is possible to know the maximal and average number of time slots that will pass until and including the time slot in which there will be a successful broadcast, knowing that two ...
0
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0answers
22 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 ...
0
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0answers
20 views

calculating the probability of a successful broadcast in p-csma protocol

am quite unsure with the following question. would appreciate your help with it: in a 3 stationed p-csma network, where \$p=0.3\$, we know that in \$t_0\$ the network is restarted, the channel is ...
0
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0answers
71 views

TCA9548A (I2C multiplexer) works for a few minutes and then hangs

I'm having trouble getting the TCA9548APWR to communicate for longer than a few minutes. I'm only able to get it to "reset" by resoldering it. I have used both an Arduino Mega and a Beaglebone Black ...
0
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0answers
28 views

Antenna formed from the RF module shielding wall and cover

Can anyone provide details how an antenna can be designed from RF module shielding wall or cover? More specifically if any company is making this kind of antenna product for general communication or ...
0
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0answers
21 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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0answers
32 views

Data communication in power harvesting project

I want to design a wearable gadget for elderly to detect falling. This gadget should work by energy harvesting. Now I want to find the best effitient way of power consumtion to send data to a station ...
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38 views

Intercom device, door-opener and door-bell

I got a Bticino intercom system (non-wireless). I did some restoration in my hallway and disconnected the device. Unfortunately I do not remember how it was wired before I set it up afterwards. Now we ...
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0answers
42 views

Wifi coaxial cable type unknown

Quick question, I was unable to identify the coaxial cable type used in wifi devices(routers ,tablets,etc.) , very thin grey cable approximately 1mm in outer diameter, I need to know the type so I can ...
0
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0answers
61 views

Generating a specific sequence of signals in Verilog with timing requirements

I am a beginner in Verilog, and as a part of a project, I have to send a sequence of signals to a chip in order to program one of its parameters. This Verilog code will be synthesized on an FPGA, and ...
0
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0answers
135 views

How is the power of a SSB-SC signal half that of DSB-SC signal?

Intuitively I get it that my SSB power has to be half of DSB power but mathematically I am unable to get this. Say working for tone modulation. $$m(t)=mA\cos(w_mt)$$ where m is modulation index. ...
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0answers
19 views

XBEE S3 PRO loses comms beyond 800 meters with a 7dbi Antenna

My XBEE S3 PRO loses some packets when transmitting 800 meters away from the XBEE Pair. Even though we used a 7 dbi car antenna with sma jack. we used a jack converter from sma to rp sma (if that ...
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21 views

What is the meaning of reciprocal communication range in the context of wireless communication?

Does it mean the carrier sense range is equals to the communication range, as this paper mentions the system has no hidden terminals due to reciprocal range ?
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122 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 ...
0
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0answers
120 views

How does GSM Module store incoming SMS in its “SM” or “ME” memory?

I am using AI Thinker A7 GSM/GPRS/GPS Module demo v7.1.(The Rx, TX, GND pins of this module are connected to tx, rx, gnd pins of the prolific Rs232-TTL converter and a virtual com port is open in ...
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0answers
37 views

Communication Theory - Basic Transmission Errors

I have a question regarding some basic transmission error: My confusion is with the solution to combat errors (transmit each frame 3 times). I would have though that the probability of receiving a ...
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0answers
28 views

UART Current in PIC18F46K22 & 7404 Input Current

I am currently making a decision to invert the UART signal from my PIC18F46K22 and have 2 choices to either use 74LS04 and 74HC04 but there is a difference between the LS and HC that the LS can output ...