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.

learn more… | top users | synonyms (1)

4
votes
3answers
65 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 ...
-1
votes
2answers
106 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 ...
0
votes
1answer
82 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 ...
2
votes
0answers
58 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 ...
3
votes
1answer
52 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 ...
0
votes
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 ...
1
vote
1answer
206 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) ...
0
votes
0answers
31 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 ...
3
votes
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?
-2
votes
1answer
63 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: ...
5
votes
1answer
133 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 ...
2
votes
1answer
110 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, ...
0
votes
2answers
331 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 - ...
2
votes
1answer
228 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? ...
1
vote
1answer
100 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
vote
1answer
99 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?
4
votes
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 ...
3
votes
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 ...
1
vote
1answer
170 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 ...
2
votes
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 ...
3
votes
2answers
157 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 ...
1
vote
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 ...
1
vote
0answers
128 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 ...
2
votes
3answers
292 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 ...
0
votes
0answers
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 ...
0
votes
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 ...
1
vote
2answers
194 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 ...
-1
votes
1answer
256 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 ...
1
vote
1answer
629 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 ...
0
votes
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 ...
5
votes
2answers
512 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 ...
0
votes
2answers
130 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 ...
1
vote
3answers
259 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 ...
8
votes
4answers
522 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 ...
5
votes
2answers
471 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 ...
2
votes
2answers
625 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, ...
2
votes
2answers
187 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 ...
22
votes
3answers
765 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 ...
4
votes
1answer
479 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: ...
3
votes
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, ...
12
votes
2answers
8k views

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?
2
votes
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 ...
2
votes
3answers
535 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, ...
3
votes
2answers
211 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 ...
1
vote
5answers
555 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 ...
4
votes
1answer
205 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.
4
votes
2answers
516 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 ...
2
votes
2answers
883 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 ...
2
votes
1answer
578 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 ...
1
vote
2answers
477 views

CAN driver - error passive state

I have a device based on TMS470R1B1M from which I try to send CAN standard frames every second. As soon as I turn on the device, the device enters the error passive state. How do I handle this error ...