LP-AM263: Can't sniff CAN messages through Vehicle SPY

alex dchk

Part Number: LP-AM263
Other Parts Discussed in Thread: MCU-PLUS-SDK-AM263X

Hello,

I want to validate CAN transmission on this EVM(LP-AM263). I need to transmit smth via CAN, and observe it in Vehicle SPY application. I'm tried both examples which are goes in MCU-PLUS-SDK-AM263X:

mcan_loopback_interrupt And mcan_loopback_polling. I though, it should be enough, but not.
In both example, I disable the loopback. But it doesn't work, the effect is zero.

Configurations of neoVI and the CCS project for LP-AM263 are attached.

Please help me, to figure out what is going in wrong way

over 1 year ago

0 Frank Livingston over 1 year ago

TI__Mastermind 28798 points

Hi Alex,

Looking at the LP schematic, GPIO51 is connected to the CAN transceiverU42.8 STB and STB is pulled high.

Looking at the TCAN1044DRBTQ1 datasheet:

8.3.1.7 STB (Standby)
The STB pin is an input pin used for mode control of the transceiver. The STB pin can be supplied from either
the system processor or from a static system voltage source. If normal mode is the only intended mode of
operation than the STB pin can be tied directly to GND.

Hence, I suggest driving GPIO51 low to enable the CAN transceiver.

Regards,
Frank

0 alex dchk over 1 year ago in reply to Frank Livingston

Prodigy 220 points

Hi Frank,

Already tried to configure it, but doens't help. See screenshots.

0 Frank Livingston over 1 year ago in reply to alex dchk

TI__Mastermind 28798 points

Hi Alex,

Can you verify AM263_CAN_STB_GPIO51 is driven low?

Can you connect a scope to J33.1 (CANH) and J33.3 (CANL)? What do you see?

Regards,
Frank

0 alex dchk over 1 year ago in reply to Frank Livingston

Prodigy 220 points

HI Frank, I'll verify this today and will come back

0 alex dchk over 1 year ago in reply to alex dchk

Prodigy 220 points

I'm back, I can confirm, that code above, can drive the pin 51 to low.

Regards your second question, I have tried to run mcan_loopback_polling freertos example, the output on J33.1 (CANH) and J33.3 (CANL) is empty

0 Frank Livingston over 1 year ago in reply to alex dchk

TI__Mastermind 28798 points

Hi Alex,

How did you disable the loopback in the code?

Looking at the MCAN API, I see this function: https://software-dl.ti.com/mcu-plus-sdk/esd/AM263X/08_05_00_24/exports/docs/api_guide_am263x/group__DRV__MCAN__MODULE.html#ga6fa88e0a4ba1aa69335990bec01f965a

To disable loopback, I suggest calling the function with the "enable" parameter set to false:

MCAN_lpbkModeEnable(gMcanBaseAddr, MCAN_LPBK_MODE_INTERNAL, FALSE);

I'm looping in a colleague for further comments on the hardware.

Regards,
Frank

+1 alex dchk over 1 year ago in reply to Frank Livingston

Prodigy 220 points

Hello, I found out the solution. There were swapped wires of CAN, so that's why I wasnt able to see can messages

0 Frank Livingston over 1 year ago in reply to alex dchk

TI__Mastermind 28798 points

Hi Alex,

Thanks much for letting me know you found the solution.

Regards,
Frank

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LP-AM263: Can't sniff CAN messages through Vehicle SPY