All Questions
28
questions
1
vote
2
answers
3k
views
K-Line vs CAN bus
I'm building an app (running on a Pi) that will communicate with consumer vehicles for diagnostics and control. I assumed that I could achieve this over CAN bus since all vehicles after 2003 are ...
- 139
0
votes
1
answer
126
views
No CANbus response to broadcast
I am trying to create a simple OBD tool in Linux to talk to my car (2009 Honda Accord). My OBD device successfully connects and I see lots of CAN frames arrive. However, when I issue an OBD command (...
- 139
1
vote
4
answers
9k
views
Getting 45.6 Ω when it should be 60 or 120 Ω on CAN bus
We have a 2011 Chrysler 6.1L Hemi SRT. We can not get any diagnostic reading at the DLC or OBDII port. We have checked all the wiring, fuses etc.
Our readings at the DTC connector are as follows: CAN ...
- 19
1
vote
1
answer
498
views
Unable to get identify CAN-H and CAN-L pinout from voltages & resistances measured at OBD-2 port
I am trying to figure out the CAN-H and CAN-L from OBD2 port fixed below the Dashboard. I unable identify CAN-H & CAN-L as I get following inappropriate voltage & resistance values which are ...
- 25
0
votes
1
answer
4k
views
0x7E8 to 0x7FH on the CAN bus?
I am currently trying to understand the working of the CAN bus. I understand that when we connect a CAN bus logger to the OBD2 port in a car we will be able to view the CAN traffic (raw CAN frames) ...
0
votes
1
answer
804
views
Need help designing an OBD2 sniffer using an STM32 F446RE MCU
I have written a simple program that should send "NO MESSAGE!" to the serial monitor if there are no CAN messages or "A NEW MESSAGE ARRIVED!" and then the CAN message itself ...
- 5
1
vote
1
answer
224
views
Some Physical Layers used with OBDII
I need to review some physical layers used in OBDII, a very common interface communication of vehicles and used as interface in a automotive scanners. I don't need exactly to know how the protocol ...
- 917
-1
votes
1
answer
147
views
Hooking up a device which is powered externally, to the OBD port of a car
I have a device called AutoPi (https://www.autopi.io) which is simply a Raspberry Pi Zero aggregated with a couple of more components.
The device takes it's power from the OBD port.
I want to make ...
- 99
1
vote
2
answers
1k
views
Selection criteria for microcontroller to read data from a car's CAN bus (from OBD2 to microcontroller)
I want to read data from a car's CAN bus using a micro-controller. The micro-controller is used outside the car (via OBD to micro-controller).
A few micro-controllers i found with CAN interfaces are ...
- 13
0
votes
1
answer
837
views
CAN BUS Termination Resistors For CAN Logger Device
I am making a CAN logger device that will be connected to the vehicle OBD port. Since the CAN bus inside the vehicle is already terminated, do I need to terminate the BUS lines on my device end, right ...
- 383
0
votes
0
answers
64
views
I am trying to make a OBD logger for heavy-duty vehicles
The thing is that I have to use one CAN transceiver and one CAN controller. Both have one interface (CANH and CANL). I use dip switches to route different CAN signals whenever I need to using a DIP ...
- 383
2
votes
1
answer
1k
views
CAN Bus sniffing
I am CE major prototyping embedded hardware to read and send data via the CAN bus. The design is coupled with a GSM/GPS module to enable tracking. I needed an EE perspective on the schematic diagram (...
- 23
1
vote
1
answer
186
views
Getting garbage output in serial monitor while communicating with OBD using CAN interface (MCP2515) and nodemcu
I am doing a project which involves getting vehicle speed from a car's OBD port and storing it in my database using nodemcu.
I am programming nodemcu using the Arduino IDE and using this library for ...
- 113
1
vote
2
answers
2k
views
How to set timeout using AT commands and ELM327
I'm working on Android app that can read data from CAN bus. The interface I'm using is ELM327. The problem is that this interface uses Bluetooth, so I cannot read all the data from CAN bus because ...
- 11
5
votes
1
answer
4k
views
Firmware design for OBD2 - available PIDs request to ECU
According to many documentations, we can request a vehicle ECU to respond with the PIDs it supports. Link.My question is in the end.
I have designed an OBD2 scanner using STM32 and CAN. And it works ...
- 386