Can't get receive messages from CAN shield with car OBD

userHead MarkT 2022-06-13 05:43:11 266 Views4 Replies

Hi there, 


I've been trying to get my arduino to connected to my Miata MX5 OBD2 via the CAN bus shield and supplied cable.


However, whatever using the example scripts to receive , I only get the first message that the shield has initialised.


i.e. DFROBOT's CAN BUS Shield init ok!


I am told that the speed of the CAN is 500kbps , so this is as in the example.


Just what needs editting to at least see all the messages on the CAN bus to check things are even working.


Any help would be greatly appreciated.



2022-08-30 11:17:22

Sorry to reply you for so long. 


We have found the reason for your problem. After the Arduino ide version is updated, the write function is no longer supported to write data in the serial port. 


The following modifications are required:


After modification, you can normally receive the data sent by CAN in the serial port. And we will update the Wiki in time.


Thank you for your support to our company.

userHeadPic Zane
2022-06-29 04:16:28

Hi there, can anyone tell me how to check the replies to this message as I can't see them even though it mentions there are two replies? 

userHeadPic MarkT
Bob.Zhuang wrote:

I think you can check the definition of MX-5 OBD.

Usually, OBD is defined as this



this is DFRobot  CAN shield circuit diagram,  It uses the  DB9 port.

A DB9 to OBD cable is required. There are two cable sequences in the market.



Type A


Type B





this is DFRobot  cable ,  it is  type B

P1 DB9 Female   P2 OBD II male  1         ——      5  2         ——      4  3         ——      6  4         ——      7  5         ——      14  6         ——      10  7         ——      2  8         ——      15  9         ——      16



I don't know what the wire sequence of MX-5 is and what cable should be used.


What kind of cable do you use?



2022-07-01 15:15:39
1 Replies