Questions tagged [bus]
is a subsystem that transfers a plurality of digital bits grouped together to achieve or represent a common function or variable.
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EMC and Control Area Networks [closed]
With radiated EMI tests, do we need to take into account the communication cabling and its influence on EMI?
I can't seem to find one standard that describes how CAN busses should be configured in EMI ...
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3
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What does it mean for a digital logic signal to qualify another signal?
The wishbone specification refers to signals being qualified by other signals:
The strobe output [STB_O] indicates a valid data transfer cycle. It is used to qualify
various other signals on the ...
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How were standard serial port baud rates chosen?
How were standard serial port baud rates chosen? 1200, 9600, 115200, aren't the numbers we'd expect (powers of 2 or 10), but don't seem random either.
Wikipedia states
Many of these standard modem ...
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Understanding ISO-TP, Flow Control and Blocksize
I am currently trying to understand can communication using the ISO 15765-2 (ISO-TP) and Unified Diagnostic Services (UDS) Protocols using can.
At this point I have a question about the Flow Control ...
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Difference between Single-supply and Dual-supply CAN Transceiver
I was about to choose the MCP2558FD CAN Transceiver for a personal project. I found on the datasheet the following diagram:
If my understanding is good, I can use it as a dual-supply Transceiver.
But ...
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Kicad: Net is graphically connected to bus but not a member of that bus
Why is KiCad 7.0.7 complaining that these wires aren't part of the bus, when I've literally labelled the bus A[18..1] and ...
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Connect two peripherals on the same SPI bus with RP2040
I'm using a RP2040 for a personal project.
I'm already using the SPI0 with GPIO 3 to 6, and SPI1 with GPIO 11 to 14. Is it possible to use the SPI0 with GPIO 16 to 19 at the same time with another ...
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Design breakable PCB for power distribution bus
I am trying to design a PCB for power distribution bus to clean up wiring mess when prototyping.
Here's my plan:
Long PCB with single trace for each copper plane.
Put pads to distribute power along ...
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1
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Drive strength and termination on a 50MHz multi-card backplane bus
I'm helping someone design a spec for a computing ecosystem based on Z80 and Eurocard. One of the challenges is that we want to support modern Z80 chips clocked at up to 50MHz, which means we have to ...
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Hierarchal Sheet - Bus - Abbreviate Contents
In an unrelated answer, user @Steven demonstrated that it is possible to abbreviate the bus contents of a pin label of a hierarchal sheet block.
How is this accomplished, such that:
• ...
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Eyeballing bus capacitance
I would like to use single-wire half-duplex UART bus to connect together two STM32 controllers and one ESP32 module. They all will have diodes on TX and share one pull-up. The wiring uses 2m of common ...
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Whats the point of SDI being "source/destination" identifier if 429 busses are only allowed to have 1 transmitter?
Every reference I've looked at for Arinc429 specification has something like this:
Okay, pretty simple. There is only one transmitter and up to 20 receivers.
However, the name of the SDI (source/...
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Genesis ROM + Level Shifter Circuit: Game Fails Without O'scope Probe
Problem:
In an effort to learn digital electronics, I've designed and had fabricated a modern Sega Genesis cartridge. But I'm having a problem getting the cartridge to work without the help of an ...
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MSP430 I2C no ACK send over Bus - updated but still not working
I'm trying to get an I2C communication with an MSP430 (MSP430G2231) working. This is the first time I'm using a MSP430 for I2C and not sure if I'm doing everything correctly.
I have a Slave connected ...
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CAN-Bus Message confusion
Can anyone tell me what the difference between these two sets of CAN Bus messages? This is from the manual of a Power Drive Unit (PDU) in the Cargo Handling System of a 747F (UPS Freight). This is the ...
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5:1 Mux design for a common bus system
I am tinkering with logic gates preparing for an exam and came across a question that states the following
Construct a common bus system for six registers where each register has five bits.
the ...
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Can a PCI bus master access a device mapped in cpu memory space
If a PCI bus master can access memory space just as cpu can, can it put an address on the memory bus of the cpu that actually triggers a memory mapped I/O device to respond to that address.
(As if the ...
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Does PCI require bus transaction routing
Does pci require routing mechanism in those 2 cases
The two devices are on the same PCI bus and aren't seperated by a bridge.
They aren't on the same PCI bus.
I don't think it requires a routing ...
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2
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CAN-Bus: Wire Impedance vs Terminal Resistor
I'm seeing several pre-fabricated "CAN-Bus" cables with (2) DB9, 120 ohm terminal resistor connections, while the cable's impedance is 100 ohms.
A. What is the purpose for this mismatch?
B. ...
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How does data reach peripherals in STM32H7xx?
I'm trying to understand bus interconnection matrix in stm32h7xx. Here is a capture of the H753's one:
In particular, I'm wondering how a data buffer located in DTCM would reach the SPI1's tx ...
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ID collision on CANOpen SDO
I am working on a remote control module to control my heating boiler remotely. The boiler uses CANOpen 125k.
My module transmits periodically SDO requests to read temperatures and other parameters. ...
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Sporadical CANbus "bus errors"
As a hobby project, I created an IoT module that allows to control and monitor heating boiler remotely over CAN bus. The bus runs at 125k and is relatively short.
Usually, after a few hours of normal ...
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Altium repeated harness connector
I would like to use a harness connector to connect two sheets in a multichannel design. If I do not repeat the sheets, the harness connector between them works well. It's better if I show it in ...
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PCIe bus bandwidth
Calculate the bandwidth of a PCIe link with 8 lanes, 8b/10b encoding and 2.5 GHz frequency.
I tried the following formula but I am not sure of its correctness:
BW = lane data rate × encoding × no. of ...
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CAN physical layer flexibility
I'm considering designing a CAN bus (CANopen) where part of the bus, closest to each node, does not use twisted pair. Partially the bus will run in a DSUB, but partially through stackable header or ...
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In a three-phase circuit, do all three phases connect to the same bus or are there three separate buses?
Below is a per-phase representation of a small power system from Power Systems Analysis (Grainger and Stevenson, p206).
I'm trying to imagine the three-phase version of this circuit diagram. Let's ...
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BOSCH CAN 2.0 with ISO 11898 High Speed CAN
I'd like to use the PIC18F25K83-E/SS micro controller with the TCAN332 transceiver to implement a CAN node. In the PIC documentation it specifies the BOSCH CAN 2.0 standard while the TCAN322 specifies ...
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Reading bus connections on a block diagram of an MCU
I'm trying to read and route the clock bus of GPIOB of this MCU from its block diagram.
Normally another type of MCU block diagram is given as follows:
So above is easy for me to say GPIOB is ...
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A Weird Way to Define Real Power Loss as Sum of Net Power Injections?
Definition
In the context of describing the power flow problem, real power loss PL is defined in Power Systems Analysis by Grainger/Stevenson as: "the total I^2R loss in the transmission lines ...
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Daily chain sensors with HIGH/LOW signal output
I'm working with 8 - 16 MTCH101 capacitive proximity sensors connected to one master MCU. Each sensor has a single output pin that is either HIGH or LOW.
Is there a general-purpose IC that I can use ...
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Modbus TCP illegal packet (CRC) time-out problem in gateway
I am connecting a Modbus gateway to an RTU acquisition system. I am using a MOXA Gateway MB3480 with a RS485 (2 wires) connector. The thing is that I can't read the data all the time; I receive a time-...
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Hot-pluggable bus design review
I am currently designing a hot-pluggable bus system where a module is connected to its respective slot via a first mate/last break spring-loaded connector. I am using PJON, in specific PJDL on the ...
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What is the rationale behind enforcing WDATA ordering in AXI3?
While trying to understand the AXI protocol,I came across this:
Write data on the W channel must follow the same order as the address transfers on the AW channel.
from https://developer.arm.com/...
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How can I design a CAN BUS hardware interface for STM32? (TTL and CMOS issue)
I am designing a PCB based on STM32F446 and I want to include CAN BUS communication. I know I need a transceiver (from CAN_H and CAN_L to TX and RX) and a CAN Controller. I have thought about MCP2551 (...
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STM32 CAN bus silent mode
I need to use the CAN bus simply to receive frame data (i.e. not transmit.)
Can I use it in silent mode?
I know that the main limitation of this mode is the fact that it does not transmit, so no ...
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Calculating bus reactor efficiency in a high-voltage substation
Say I have time-series data-set containing the active power, reactive power, and voltage of a substation. I know the switching history of those bus reactors and obviously the MVAR capacity of the bus ...
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Solving different voltage for I2C pull-up resistors
I am designing my own PCB (based on the STM32F4). I am communicating with some devices using I2C.
The thing is that this devices are connected to the I2C bus, which uses two 4.7 kΩ resistors (pull-ups)...
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Does SPE (Single Pair Ethernet) require termination?
It is stated that it needs 100 ohm termination resistor but is it end of the each line externally?
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Can M-LVDS be used as bus protocol?
https://www.analog.com/media/en/technical-documentation/application-notes/AN-1177.pdf
In the document, it states that CAN is robust but M-LVDS is low power alternative of that. However, I couldn't be ...
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Intel 8086 register bus default to high logic with pull-up resistor?
This schematic from righto.com's article on the register of 8086 shows a bi-stable latch with inverters.
When the read line is set to high, and the inverter output is also set to high, the bit line ...
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What communication protocols can I use with maximum 2Mbps, with simple a simple cable (two wires, unshielded, untwisted)? [closed]
I need to find a communication protocol/module (on market product) in order to provide M2M (max 64 devices) communication at a maximum rate of 2 Mbps and a range of up to 30 m.
The cables/cable should ...
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How to connect Harness to Bus on Altium?
I am trying to connect PD Controller to 2 child USB Type C Connector by repeating.
I created Harness connector both PD controller and USB COnnector side. But nets did not connect on the PCB.
How to ...
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Novel CAN bus design - needs criticism
I'm designing a CAN bus interface for a PCB I'm working on. CAN and high speed/long distances are new to me, so I have a list of concerns about my design ideas, and I would appreciate someone with ...
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Schematic Notation
I am reading a schematic to find the current leak of my car battery.
What is the dotted line between the top of fuse 6 and 17?
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I2C Hot Swap design and feasibility
I would like to hear if someone has successfully implemented a working connectable/disconnectable I2C interface. I'm working with the back plane (host device) and am looking into implementing a I2C ...
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How to convert a double data rate (DDR, DTR) signal in a single data rate (STR) signal?
Is there a simple way (simple hardware) to convert a DDR signal to STR signal?
Example:
8 bit DDR bus at 25 MHz to 8 bit STR bus at 50 MHz.
For LCD communication at 1.8V or 3.3V.
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Topology and protocol for boards connection
Would like to have some insight on which data protocol to use to communicate between a master and several slave boards on a project i'm working on.
My initial idea was to daisy chain all the slaves. ...
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RS-485 Network Topology with Backbone and Daisy-Chain Stubs [closed]
I am designing a RS-485 network and would like to know whether the configuration below would work. The transceiver I am using is the Maxim MAX485, with the master ad slaves hardwired to always ...
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Protect bus and remaning bus-attached devices for bus-attached device failure (CANBus)
What are options to protect CANBus from failure of device connected to bus?
For example if CAN Transceiver pulls bus high or low. Or some other sort of electronics failure.
Thx
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CAN bus idle voltage too low
I'm testing a CAN bus circuitry based on MAX3051. VCC is 3.3V
Two nodes are only connected on the bus. Termination resistors 120 Ohm are on each end of the bus.
When the bus is in idle state (no one ...
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