CAN communication (no data visible on CAN HIGH or CAN LOW side of transciver TJA1050)

[Ash1]

Hi all 

I am trying to run CAN communication (normal mode ) from my discovery board (STM32F407) to USB CAN analyzer via (TJA1050).

I am able to see data on TJA1050 (CAN TX and RX side ) but no data is reflecting on CAN high and CAN low side, so because of no data is showing on CANH and CANL ,no data is reflecting on USB display (note: only rev led is blinking on USB CANAlyzer)

what can be issue ?

B.R

Ashish

PFA attached 

CAN

[SofLit]

Hello @Ash1 and welcome to the community.

What you did set as voltage level to S pin (Silent mode) of the transceiver? 

If you kept S pin not connected or connected it to VDD, the transceiver will be disabled, so you need to pull that S pin to GND.

[Ash1]

Hi Soflit 

I have already ran this program two months ago it was working fine I have never used this method even ,so why I should use this one when it was working fine I didnt do any thing change .

Note: First time I am hearing this concept (selecting voltage level for S pin) I have already ran this program with same parameters and connection ..

B.R

Ash

[SofLit]

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@Ash1 wrote:

I have already ran this program two months ago it was working fine I have never used this method even ,so why I should use this one when it was working fine I didnt do any thing change .

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You didn't mention that in your first post. I'm answering based on the information you gave.. No one have a crystal ball to know what you did.

Now, even it worked fine previously you need to check again all the hardware stuff including the S pin voltage level and the transceiver power, your wiring etc ..

You may share your schematics and your source code so we can help you efficiently.

[Ash1]

hi Soflit

PFA  code for your reference

[SofLit · Accepted solution]

Hello,

First, please use </> button to paste a code in the community. Please read Tips on how to post a thread in it.

Second, CAN has two subjects to treat: HW and Software. You just pasted a reduced code of the transmit. This does not help us to move forward .. So please:

1- Share your project

2- Share your schematics

3- Confirm again your HW status: S pin voltage / Transceiver power supply, wiring and connections, availability of two terminating resistors.

Thanks