CAN stands for Controller Area Network and is a bus often used in automotive applications. It is a two-wire differential protocol and works on baud rates from 10 kbits/sec to 1 Mbits/sec.

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Super slow serial (UART) communication on Arduino [migrated]

I am using this device for my Arduino that connects to the OBD-II port of my car to get various information such as speed, rpm, etc. I am using this for a digital Nixie tube speedometer using the ...
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3answers
67 views

Is the CAN bus protocol a master and slave protocol?

I am investigating if the CAN bus will work for the projects I am building at the moment. I want to create a bunch of input/output controllers that will accept/buffer commands, execute them and then ...
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2answers
108 views

How to properly wire 2 CAN transceivers to the same CANH and CANL

I'm attempting to design a system with 2 CAN transceivers, a High speed and Low speed that use the same CANH and CANL lines, like so: I was planning on using 4 MOSFETs or 4 Relays connected to the ...
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1answer
83 views

CAN communication with the SM470R1B1M-HT microcontroller

I bought the IAR Kickstarter kit to work with the SM470R1B1M-HT (Texas Instruments) microcontroller. I would like to implement CAN communication between the microcontroller and a PC. I need to send ...
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61 views

Android CAN bus connectivity via Bluetooth (or USB) [closed]

I'd like to read sensor data from existing CAN buses using a bluetooth (preferably, though USB would also work) device of some sort. Trouble is, I've never done CAN bus, bluetooth or android ...
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1answer
53 views

Understanding the guaranteed data consistency within CAN network

I am reading the CAN spec and it says the following about data consistency: Data Consistency: Within a CAN network it is guaranteed that a message is simultaneously accepted either by all nodes or ...
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2answers
80 views

Isolation of CAN-High and CAN-Low signals [closed]

I have to isolate the signals CAN-High and CAN-Low on a CAN bus. Is there an isolated CAN repeater (something like IXXAT's CAN-Repeater - 110 × 75 × 22 mm) which would be ...
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1answer
214 views

What do chips like ELM327 and STN1110 do?

What problems are the chips ELM327 and STN1110 solving? If I connect the necessary interface ICs (I mean dumb ICs, like level shifters, inverters, etc., not pre-programmed devices like ELM327) ...
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33 views

OBD2 CAN digital analysis yields signal only on CAN Low

Since I don't seem to find the OBD2 CAN specification anywhere on the internet, I am trying to reverse engineer the signaling done so that in the end I can develop a piece of hardware that will act as ...
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1answer
61 views

CAN bus ESD protection

For a CAN bus application, is it correct to connect an ESD protection IC to GND, or chasis of the device?
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1answer
64 views

Data transmission via CAN

I'm trying to send data out via CAN rather than using a serial port. I could output the following via serial port without a problem using FIFO buffer: ...
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1answer
135 views

CAN bus troubleshooting. How? [closed]

I am trying to connect ICP CON i-7565 (USB <-> CAN interface) to a custom made device (supporting CAN 2.0B, proved to work with PCL-841 card). Although I think I have configured the Baud rate and ...
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1answer
115 views

Controller Area Network (CAN), high speed and low speed

Is the difference between high- and low-speed CAN only with respect to baud rate values? Is the CAN transceiver programmable for a range of speeds or is it fixed for a specific value? For example, ...
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2answers
340 views

Reading from CAN bus of a Chevrolet Cruze using an Arduino Uno

I'm using the Arduino Uno, CAN bus shield, and OBDII to DB9 Cable using their provided libraries. I was only able to initialize it. Readings: While connected to the car: CAN-High: 2.7 V - ...
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1answer
237 views

Reading and writing CAN messages through ELM327

I have an OBD-II cable, and an UART-to-OBD-II board which has the ELM327 IC in it. I want to communicate with my ECU by sending-receiving CAN messages. Is it possible to communicate through ELM 327? ...
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1answer
105 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 ...
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1answer
101 views

Is it possible to have any CAN baudrate?

Is it possible to have any CAN baud values? e.g. 507 baud If not, on what basis is the standard values are derived?
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1answer
92 views

Why are my microcontroller and CAN transceiver failing?

I have a PCB with a dsPIC 30F6012a and a TI ISO1050 isolated transceiver. This is a combination of devices I've used regularly. The two chips' CAN TX and RX are wired directly to each other with no ...
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3answers
258 views

Designing CAN for a 3.3V system

I am currently designing a CAN system for a 3.3 V board and I am looking for some insight regarding CAN transceivers. These are my goals from the CAN system: No influence on the CAN bus if in ...
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1answer
173 views

GPS over CAN bus

How is GPS data typically sent over CAN bus? Some context: I'm looking to simulate sending and for receiving GPS data (using a Linux-running embedded device with CAN interface), to work side-by-side ...
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0answers
52 views

Do you consider this design as an application layer on top of the CAN protocol?

This is a follow up question from my previous question about How do I program 2 CAN nodes to transmit continuously in succession? I'm planning to add another layer on top of the CAN protocol and I ...
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2answers
160 views

How do I program 2 CAN nodes to transmit continuously in succession?

Suppose I have three CAN nodes: A, B and C. We know that when two nodes transmit at the same time, the node that has the least SID will prevail over the bus and the other node will have to give the ...
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2answers
128 views

Industrial RF replacement for Xbee based UART communication

I have used Xbee's several times and I am working on a basic project which involves multiple MCUs talking to a central MCU and sending some updates such as Temp, GPS and etc... Very basic setting ...
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129 views

Issue with CAN communication

I'm new to CAN and currently having problem with a setup. The image shows how my devices are connected to each other. I'm using the canutils Linux package to send messages (Linux uses its network ...
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3answers
295 views

I²C, SPI, CAN protocoles and OSI model

could you please refer me to a reference or explain me if I²C, and SPI ** are just **Physical layer protocols in OSI model (i know that this model is for communication and maybe not exactly for ...
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72 views

USB to COM line to replace USB-CAN device

Can I use a USB to COM line to replace USB-CAN device? I mean "USB to COM line" is something like this: USB-COM image And a USB-CAN image is here: USB-CAN image I'm working under Ubuntu 12.04 and ...
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1answer
129 views

Finding timestamps of CAN messages received by a microcontroller

The microcontroller kit (STM32F4 discovery kit) which I am using has CAN and USB support. I want to program my microcontroller so that each time when a CAN message is received, it is transmitted via ...
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197 views

What is the most efficient way to debug CANbus from a PC?

I have several working and inter-operable boards using CANbus. I've shipped hundreds of products using these boards, with no problems. One of my customers is now saying that his fault log shows ...
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1answer
259 views

USB to OBD-II Converter

I want to make a scan-tool that works via a PC for my Thesis. To test it I have bought an ECU simulator (ECU-Sim 2000) with a CAN bus. I'm planning to make it using an FT232H USB to serial chip and a ...
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1answer
635 views

PIC18F25K80 can transmit over CAN but can't receive

I've built a prototype circuit on a solder breadboard. I've connected the PIC18F25K80 to MCP2551 as shown in the schematic for ...
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0answers
54 views

NXP TJA1043T CAN Transceivers wakeup problem (when switching KL30 ON)

I have a problem with TJA1043T CAN transceiver. When the ECU is in sleep (KL15 OFF and KL 30 OFF) and after a while(40 seconds) the KL30 is switched to ON (but KL15 is still OFF), the communication on ...
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520 views

For the CAN bus, is it OK to swap CANH and CANL lines?

Similar to question In a USB cable, is it OK to swap the D+ and D- wires?, is it okay if we interconnect CAN-H and CAN-L lines? CAN is a differential protocol. Is it that dominant and recessive bits ...
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131 views

Sending CAN protocol data(1Mbps) via serial port

I would like to build a tool for viewing CAN protocol data on my computer. The CAN protocol data is captured using a microcontroller (STM32F4 discovery board) and sent to a PC via a serial port. My ...
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3answers
262 views

TXERR error in CAN communication

I tried CAN communication using PIC18F25K80 and MCP2551. Using two nodes, I could transmit data from one node to other. But, data was transmitted only when the receiver buffer was set to ignore all ...
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5answers
561 views

Selecting communication between microcontrollers at high temperature

I have been assigned to a project to find the best possible communication between several PCB boards which have microcontrollers for a specific function. I need to have all microcontrollers ...
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2answers
480 views

CAN Transmission and termination resistors

I have been trying to set up a CAN network using PIC18F25K80 microcontrollers and an MCP2551 to communicate between them. Can I use two simple wires as a CAN bus by just connecting the CANL, CANH of ...
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2answers
630 views

Can I remap a car\bike ECU using CAN bus?

I am thinking to use something like this to connect an Arduino to a motorbike engine control unit (ECU): Arduino CAN-Bus Shield with uSD Card Holder. I never did something like this; using CAN bus, ...
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2answers
188 views

Best microcontroller electrical bus for high speed synchronized sampling from slaves

I have an application which requires that I sample a dozen of sensors for each node and transmit the data to a master microcontroller in regular four second intervals. The surface area of the sensors ...
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3answers
769 views

Correct place to attach shields for twisted pairs

I have two PCBs connected by a cable containing 5 sub-cables: 6v power through a custom made coaxial cable (similar to that found on laptop power supplies). 2x 100mbps LVDS through 100ohm impedance ...
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1answer
481 views

CAN bus bit timing with 16 MHz crystal

I'm trying to receive CAN messages from a radar, whose specification define the following data for bit timing: ...
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1answer
158 views

Coax cable with CAN bus

I got some Microchip CAN transceivers and some Stellaris Launchpads from TI. I would like to learn how CAN works. It looks very nice for what I want to do (one controller per room, controls lights, ...
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Why does the CAN bus use a 120 ohm resistor as the terminating resistor and not any other value?

I know the reasons for using terminating resistors on a CAN bus and how important it is. But why 120 ohm? How did this value come up? Is there any specific reason to use 120 ohm?
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2answers
1k views

1-wire verses CAN-bus for home sensing network?

I'm trying to put together a home automation solution for my newly built house. I'm very new to this, specifically for hardware matters and asking this question to verify if my understanding of what ...
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3answers
538 views

Most efficient way to handle addressing / termination in a daisy-chained CAN bus?

I'm working on some devices that will talk to each other over CAN. The simple idea is to daisy chain essential signals between each device: power (+12V and ground), enable and CAN high / low. Now, ...
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2answers
213 views

Packet loss in CAN

How susceptible is a CAN bus to packet loss, and what are the sources of packet loss in CAN? I realize the answer may depend heavily on the application, so here are some details: bus length: about ...
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5answers
556 views

Is CAN bus communications enough to update firmware?

I am going to control a few microcontroller-based units (approximately 30) from a master computer. They are going to be connected using a CAN bus The furthest lying unit may be approximately 10 ...
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1answer
206 views

CAN controller in a CPLD

As I cannot manage to find it done on internet, I wonder if it is possible to program a CAN controller in a CPLD ? It's look like it is going to require a least an FPGA.
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521 views

Transmission of different messages with the SAME ID on a CAN bus

CAN arbitration is done with IDs, and any node on the bus can transmit with any ID (ideally it should not, but a nasty node can). What if two different nodes connected on the same CAN bus transmit ...
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2answers
887 views

CAN bus system causing me extra work!

I bought a car reversing sensor system... I bench tested it with a simple 12 V PSU, and it works great. Integrating it into my car is another matter since finding out that most cars since 2008 ...
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1answer
579 views

CANopen frame format?

Is there a resource that describes how CANopen frames are constructed down to the byte level? I'm trying to decode a hex dump from a CAN bus, see the image below. The high-level CAN messages that ...