All Questions
37
questions
3
votes
1
answer
146
views
UART communications using CAN bus differential signalling
I need to interface with a device that talks UART, but with CAN bus signalling. Here's a picture where a tester (which I want to replicate) talked to that device:
While RS485 seems similar, the ...
- 175
0
votes
2
answers
80
views
RS485 to CAN converter
I want to design where a RS485 Device Sensor reads inputs and the information it reads and sends is converted to CAN (Arduino UNO R4 Minima with CAN built in, or ESP32 with CAN built in)
Is this ...
4
votes
4
answers
399
views
What technology to use with multiple embedded systems talking to each other?
I am planning on building a system with one master and multiple slaves using MSP430 microcontrollers. The microcontrollers must talk with each other with serial interface using RS-485. I now need to ...
- 45
0
votes
1
answer
111
views
RS485 to CAN transceiver converter
I am using an ESP32 that has a CAN transceiver on it. I want to be able to communicate with an RS485 device.
Below is a block diagram of the high-level schematic for this:
Can someone assist with ...
- 2,391
1
vote
1
answer
673
views
Using CAN with Teensy 4.1 is better than using RS-485 which requires extra converter?
I am using Teensy 4.1 and need to communicate with motor driver which supports CAN and RS-485.
In teeny4.1 CAN is supported yet it requires CAN transceiver whereas if I want to use RS-485 I need to ...
- 525
3
votes
2
answers
829
views
CAT6 for both RS485 and CAN in same cable
I have two devices which need to talk to two controllers about 60m away in the garden.One uses RS485 and one uses CAN.
I have to run armoured CAT6 for this and wondering if I can use the same run for ...
- 31
3
votes
2
answers
1k
views
Alternatives to CAN for multi-master transmission
As usual these days I'm fighting against component shortage. As in completely redesigning boards since they give us lead times in the 2023 years.
At the moment I have this product line where the ...
- 8,536
0
votes
1
answer
6k
views
Modbus Vs CANopen - Which one should I choose?
Modbus Vs CANopen - Which one should I choose if I want:
Broadcast to all units
Talk to specific units
Robust
Send lots of data
Implement for embedded systems
Easy to use
Using in new projects with ...
- 1,324
8
votes
4
answers
3k
views
Why common-mode choke on differential-signal serial lines?
I have 2 questions:
Why using a common-mode choke on serial communication lines (like CAN, RS485) if the signal is differential? Wouldn't the common-mode noise simply be cancelled in the receiver?
I ...
- 83
0
votes
1
answer
689
views
Help in deciding between RS485 or CAN [closed]
PROBLEM
I'm building a robot control board to attach to a Raspberry Pi as an hobby. I like to have specialized boards for various functions, and I'm exploring solutions for the communication bus. In ...
0
votes
2
answers
1k
views
Star configuration using CAN Bus, I2C or RS485
I need to create a sensor network, with a central node receiving data from +10 different nodes, each one +20meters from the central node. So basically I need to create a star configuration, with a ...
0
votes
1
answer
1k
views
CAN Bus with RS485 CAN HAT for Raspberry PI
I have set up a CAN bus between 2 STM32 Nucleo's, where one is only sending messages and the other one is only reading them. This works, I have also validated this by connecting them to another CAN ...
0
votes
1
answer
137
views
Bus communication scheme for large number of devices (255+ nodes)?
I'm trying to figure out the feasibility of setting up some type of differential bus communication for up to 400 devices outdoors. The main constraints are mainly power consumption, complexity, wire ...
3
votes
1
answer
677
views
Grounding in CAN / RS485 Busses
I'm interested in how to properly realize Grounding in a CAN / RS 485 bus setup.
From my understanding, when non-isolated transceivers are used, in addition to the differential signal lines, a third ...
- 71
0
votes
0
answers
48
views
Sharing Isolated Power supply for CAN and RS485
I am using ISO1432 from TI for isolated RS485 transceiver function. And ISO1042 for Isolated CAN transceiver. Both devices requires an isolated supply on bus side. Can I use one isolated 5V DC-DC ...
- 172
1
vote
1
answer
197
views
RS485 over CAN: when and why?
I'm designing my own home automation gateway and I've already added a rs485 transceiver, everything is fine, but I'm thinking about adding also a CAN bus transceiver because I've seen that it's often ...
- 579
0
votes
1
answer
297
views
Printed circuit board connector identification
I have a PCB with some connectors and wanted to identify which type there are of.
How do the experts approach the problem, to identify the type?
For example, the picture below shows a connector, ...
- 103
2
votes
1
answer
947
views
Using CANbus cable for RS-485
I have a question regarding an application with a Modbus RTU network.
I would like to know if it's possible to use a CANbus cable instead of an RS-485 cable? Here is a picture of the cable:
- 23
3
votes
1
answer
230
views
Is it possibile to use a CAN transceiver to send RS485 data?
Looking at the signal ranges I'm not sure if I can use a CAN transceiver (not controller!) to send data to a single RS485 device.
- 1,235
0
votes
2
answers
87
views
How to connect a few shields correctly?
There are several shields on my PCB: shield on CAN-bus, on RS485, on Ethernet, on ENCODER motor signals.
How do I correctly connect all these shields? If I use the star topology, which filters should ...
2
votes
1
answer
4k
views
Can RS485 be considered a multi-master bus?
There are some electrical specifications specifically designed for multi-master protocols such as CAN, I2C, 1-Wire, etc. which are classified under CSMA/CD networks.
However, RS485 has a push pull ...
- 1,426
0
votes
2
answers
146
views
Medium Range Two Wire Bus Recommendations?
Do you have any recommendations for a medium range (~10 meters) two-wire bus?
My supply voltage is 24V and I'll have a single master with ~50 slaves connected to it.
I've looked into:
I2C - Great but ...
- 1
2
votes
2
answers
133
views
How to select the most appropriate (serial) bus for controller?
In the context of a robotic project where different 'payloads' and/or robotics arms (end-deflector) should be mated mechanically with power, data and control connections support, I would like to ...
- 21
1
vote
2
answers
1k
views
Where to use CAN v RS485
Not sure whether this is too broad a question but...
Why would one choose CAN Bus over RS485, or vice versa, as a system interconnect?
I have a MCU SBC with multiple interfaces including the two ...
- 14k
2
votes
1
answer
237
views
RS-485 + iCE40 for better CAN-FD
This is an idea I have been toying with for a while and wanted to get an opinion. When I first heard about CAN-FD I thought it was going to be the answer to this problem. However most mid range ...
- 91
3
votes
4
answers
4k
views
Communication between BMS and PC via CAN/RS485 — where to start?
I am about to obtain BYD B-Box LV Residential battery for my off-grid solar system. The inverter I have is not on the list of compatible ones, which means (according to my local battery supplier) that ...
- 445
1
vote
1
answer
991
views
Identify Single wire communications protocol [closed]
Hi guys
I I have uploaded pictures from an oscilloscope.
This is the signal that an indoor AC unit sends to the outdoor unit. It uses a single wire for communication and Seeing the PCB it looks like ...
- 11
3
votes
2
answers
181
views
What serial communication interface would work best for data logging when the nearest sensor and main MCU are (at least) 1 meter apart?
I would like to setup a "sensor array" which has 4 sensors attached to it. Each sensor is expected to send data at rates of up to 8 Hz. The data would be shipped off to an MCU that is around 1-2 ...
0
votes
2
answers
10k
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 ...
- 395
15
votes
2
answers
25k
views
Significant differences between CAN and RS485 regarding the physical layer
In comparing the physical layer of CAN and RS485, I am trying to find the advantages of either one over the other. I found out that they are quite similar. Both are good in terms of common mode ...
- 696
8
votes
1
answer
4k
views
Effect of splices on 120 Ω twisted pair cable impedance a.k.a correct way to attach stubs to the bus?
I am currently in the process of designing a wiring loom for a race car control system which must also connect a number of devices via a CAN bus.
This is my first encounter with CAN bus (J1939-15) ...
- 83
1
vote
2
answers
1k
views
Multiple UART output sensors on one serial port [closed]
I would like to connect 4 UART output sensors to one serial port of my controller. The distance between sensors and controller will be about 10m. Initially I was thinking of using 485 as physical ...
- 19
1
vote
2
answers
180
views
Redundancy for a databus transmission
I'm going to start a project in my University in a few week. Since it is a collaboration between my University and a very important company I cannot say too much about the project itself. So I try to ...
- 135
2
votes
3
answers
180
views
Transit between RS485 and CAN
I have two transceivers, one for CAN and one for RS485, and both are isolated. Both standards require 3 wires (two differential pairs and one common GND).
I am trying to use one termination connector ...
- 673
3
votes
1
answer
95
views
Differential bus transmission
I am working at a project which requires an application which has some devices connected through a bus (RS-485 || CAN), I haven't decided yet.The problem is that some of this devices are hot pluggable ...
- 426
10
votes
3
answers
17k
views
Running CAN bus with RS-485 transceiver
Recently I had a discussion whether one could use RS-485 transceivers for a CAN-bus network in order to gain the flexibility to use the same hardware either in a CAN-environment or in half-duplex RS-...
- 1,845
4
votes
1
answer
972
views
RS-485 / CAN signal levels
From what I know, CAN at the physical layer in the "recessive" state just lets pull-up/pull-down do the work.
Does that mean the rise time is theoretical slower than a RS-485 transceiver?
And about ...
- 1,022