All Questions
Tagged with can transceiver
33
questions
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73
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How does CAN transceivers output CANH=3.5V and CANL=1.5V? [duplicate]
This is a questions that has been asked but did not find a clear answer. How it is the 3.5V achieved on CAN_H? Assuming there is 0.5V voltage drop on the internal diode, 0.1V on the internal MOSFET ...
3
votes
2
answers
165
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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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1
vote
1
answer
88
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Estimating max total supply current of all CAN transceivers on the bus
I'm designing the devices that should communicate via a long CAN bus (500+ meters). The power (24V) to the devices is delivered via the same bus cable (UTP5e), by the rest 3 pairs.
The limiting factor ...
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2
votes
3
answers
908
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CAN controller with UART interface IC?
Recently I have new request to add CAN interface for communication, but there is no CAN interface in current MCU. Then I found I can add a CAN controller with SPI interface to achieve.
My question is ...
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3
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2
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1k
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Why are capacitors and resistors commonly used with CAN High & CAN Low lines?
I often see resistors and capacitors connected to the CAN high and CAN low lines but in my experience, communication between nodes is still functional without these components. Can someone please ...
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3
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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 (...
1
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1
answer
386
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What chip is this? I suspect it's a CAN transceiver
I couldn't find this part number after googling.. both chips appear to say:
NXP
A42/3C
EVG000 (or EV0000)
nD921
but it's hard to read. Here's a pic below. I'm guessing they are the NXP TJA1042, ...
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2
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3
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333
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CAN bus fault protection
Question:
Is there a way to implement with discrete components the 70V CAN bus fault protection found in some transceivers, such as TCAN1051H-Q1?
Background:
We are using the CAN transceiver ...
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4
votes
1
answer
1k
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Troubleshooting CANbus 2B comms on ESP32-WROVER-based custom PCB (ABOVE WARN, ERR PASSIVE, BUS ERROR)
I am building an ESP32 WROVER-based custom PCB which includes CANbus 2B communications. This PCB is a copycat of my breadboard project.
Though on my breadboard version, the CANbus works like. charm, ...
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412
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CAN bus termination resistor
I'm trying to design a CAN device where the user can select which device is the beginning/end device and activate the 120 ohm resistor accordingly. I've seen some examples using a switch, but I'm ...
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208
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CAN Transceiver circuit problem with TJA1042T/3
I am a novice designer who recently started designing circuits.
Using the STM32f407VGT MCU operating at 3.3V, using the CAN1TX(PB9) CAN1RX(PB8) pins, the circuit was configured by referring to NXP's ...
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0
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2
answers
2k
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CAN bus expander circuit
I am trying to design a CAN bus expander. In this case I could implement star topology of multiple buses in parallel. It would avoid having problems with reflections and delay.
For this purpose I ...
0
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0
answers
638
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Normal Mode of CAN Controller in STM32L476 Nucleo Board is Not Working
I am using STM32L476RG Nucleo board which contains only one CAN controller(bx_CAN1) and SN65HVD233 as a CAN Transceiver. I could able to test the CAN controller by using "LOOPBACK Mode".
...
0
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2
answers
387
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SN65HVD232: Will it work if VCC = 5V?
Datasheet - SN65HVD232
Full part no - SN65HVD232D
My schematic -
Hi all, there is a problem in my PCB where 5V track is connected to VCC pin instead of 3.3V. Actual input should be 3.3V as per ...
3
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2
answers
1k
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How is a CAN transceiver's common mode voltage range extended?
The CAN Standard states a max. common mode voltage of -2 V to +7 V. There are transceivers however, that allow for e.g. +-25 V common mode voltage range. How is that achieved? I imagine (I do not ...
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2
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897
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CAN transceiver interface with two CAN BUSES
I would like to use the NXP TJA1046/TJA1048 dual CAN transceiver to connect to two CAN BUS. I would like to mux the TX1/TX2 and RX1/RX2 and connect them to single TX/RX interface on the MCU. In order ...
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2
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0
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3k
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MCP2551 with STM32 MCU
im learning about the CAN protocol, and bought the transceiver module MCP2551 like this:
I made the driver for CAN controller first in loopback mode for debug, im sending the numbers 1,2,3 and 4 with ...
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0
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300
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Sending Serial Data via CAN transciever
I am required to transmit a standard Hex payload through serial com port to a device that has a CAN transceiver. The serial configuration is as follows: 500 kbps, 1, 8, None, 1.
The DUT has a CAN ...
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4
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0
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189
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Compatibility and Interoperability Between CAN Standards
I'm intended to design a CAN system for a automotive scan tool. So, I need to comprise the main CAN standars used nowadays. Searching on the web I found the following options:
ISO 11519-2:1994 – Low-...
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1
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2
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CAN transceiver interconnection to MCU (Tx, Rx and propagation delay)
I am working on a CAN transceiver and its connection to a microcontroller (hardware perspective only.)
Referring this appnote - What is CAN?
My questions:
In the above image, I see the CAN ...
user220456
5
votes
2
answers
4k
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Is there hardware compatibility between CAN 2.0 High Speed, Low Speed and CAN-FD?
I am studying CAN interface hardware for the design of an automotive scanner. So far, I have identified the following types of CAN:
CAN 2.0 High-Speed: bit rate up to 1Mbps
CAN 2.0 Low Speed: bit ...
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2
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1k
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Can you use a CAN FD transceiver for low speed (fault tolerant) CAN?
Fault tolerant CAN (ISO11898-3) is terminated differently than high speed CAN (ISO11898-2). Therefore the signal levels for dominant and especially recessive bits differ.
Newer CAN FD compatible ...
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2
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1
answer
4k
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How does a CAN transceiver work?
CAN Transceiver Transmit Mode
I try to understand the transmit functionality of a CAN transceiver. I found this post a good starting point, but it doesn't completely answer my question.
Block ...
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1
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69
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Connecting CAN transceivers for devwork /home prototyping
I'm doing some home project, and would like to use this CAN transceiver (note just in case, not selecting CAN controller+transceiver chip, that's how I need it).
I would like to use this transceiver ...
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2
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2
answers
2k
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Isolated CAN transceivers as a CAN bus extender
I am designing a system to 'hack' into a CAN bus. My first idea was to split the target CAN bus, terminating both ends into isolated CAN transceivers, and use a MCU to pass packets between the buses ...
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1
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2
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778
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CAN transceiver Vref connection
I am using the TI SN65HVD230DR CAN transceiver on two separate CAN buses between three microcontrollers (MCUs) -- two are on the same board, and one is off-board. This transceiver includes a Vref pin:...
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1
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1
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166
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Should I take precautions when using different CAN transceivers on the same bus?
What are the precautions I should be aware of when using different transceivers on a CAN bus?
What I can think of:
They neeed to operate at the same voltage (on ...
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3
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1
answer
4k
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Simple CAN bus design, communication issues
I am trying to get some simple communication between two boards that I've designed with an ATmega328P microcontroller and MCP2515/MCP2551 combination.
The design is as follows:
I have both ends ...
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4
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1
answer
2k
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How can CAN transceivers ouput CANH=3.5V and CANL=1.5V?
When sending a dominant bit (0bit) on the CAN bus, I understand that CAN transceivers output CANH=3.5V and CANL=1.5V.
But when looking at the schematics of a CAN transceiver, I do not understand how ...
5
votes
1
answer
2k
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Basic CAN-BUS circuit - what does this section do?
I'm currently learning how to make a circuit for CAN-BUS communication and came across the schematics of the Sparkfun CAN-BUS shield for Arduino (can be found here). I'm a little puzzled by this ...
5
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2
answers
8k
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Multiplexing a CAN bus
I want to use a small 8 bit microcontroller which has only a single CAN rx/tx, i.e. Atmel 32c1, but in my application I need to be able to send and receive requests from two CAN buses.
I have read ...
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2
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1
answer
5k
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Single wire CAN // Saab 9-3 I-Bus // GMLAN
I'm trying to control an instrument cluster from a 2008 Saab 9-3. It has 2 pins marked for I-Bus (both wires are green, continuity test shows they are tied together as shown here:
Some sites also ...
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1
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2k
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Controller area network voltages
The CAN bus has CAN-High and CAN-Low lines. Normally, in the recessive state the voltages are each 2.5 V and in the dominant state the CAN-High line goes to 3.5 V and the CAN-Low line goes ...
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