LP-MSPM0G3507: LP-MSPM0G3507 NACK errors on the MCAN bus

Please refer to this demo code:

mcan_application_LP_MSPM0G3507_nortos_ticlang_20250801.zip

You can modify the filter here, I set 4 filter in syscfg.

You can get rx data here:

And send tx here:

For the hardware setup, please double check syscfg pin assignment.

I have just tried this code and still get NACK errors on every frame. I double checked the pin assignement in sysconfig (Rx = PA13 and TX = PA12) which is correct according to the launchpad user guide.

I have tried it on a second launchpad and get the same errors.

Am I to understand that the example code from mcan_message_rx in mspm0_sdk_2_09_00_01 is not functional?

Also, please reply to my original request, I do not need filters nor TX right now. All I need is for the microcontroller to aknowledge the CAN frames that I am generating on the bus. mcan_message_rx should be the example to follow in this case no?

Francis Poirier said:

I have just tried this code and still get NACK errors on every frame.

NACK means there is no other CAN node on CAN bus, only the sender itself, emmmmmm, just need to confirm your CAN bus signal is connected to M0 CAN controller via the CAN transiver.

Francis Poirier said:

Am I to understand that the example code from mcan_message_rx in mspm0_sdk_2_09_00_01 is not functional?

All the can demo in SDK should be functional. I didn't see any issue on that.

Francis Poirier said:

I do not need filters nor TX right now.

Both filter or Tx won't influence the ACK signal, all can controller need to ACK any CAN frame.

Francis Poirier said:

mcan_message_rx should be the example to follow in this case no?

Yes, it's enough.

This is how I am set up, using the SOIC8 TCAN devkit and the LP-MSPM0G3507.



This setup is taken directly from the MSPM0G hardware developement guide. 

RXD is connected to PA13, TXD is connected to PA12.

As you can see in the image of my original request, the CAN transceiver is working as expected and generating 3.3V CAN messages from the messages sent on the CAN_H and CAN_L bus.

Francis Poirier said:

As you can see in the image of my original request, the CAN transceiver is working as expected and generating 3.3V CAN messages from the messages sent on the CAN_H and CAN_L bus.

That seems ok for me.

And based on your previous NACK error, that means MSPM0 is not on a CAN bus yet or MSPM0 CAN controller is not inited successfully.

Here is my suggestion:

a CAN send test at M0 side will make sure that your hardware setup is OK, since can send won't be difficult at M0 side.

You can directly monitor CAN bus using your CAN analyzer.

This is the easiest way to confirm the CAN bus is OK.

Then you can further debug your Rx function.

Since this demo mcan_message_rx will only support one time CAN Rx, please pay attention to yout send timing.

I understand that you only want a CAN rx function, but trust me, this is easy to use:

Helic Chi said:

mcan_application_LP_MSPM0G3507_nortos_ticlang_20250801.zip

-------------

Also, need to make sure that there is no logic level issue when you connect STB to 5V, but other logic level RXD/TXD is 3.3V.

Hi,

I have just tried to do a CAN tx test using the demo mcan_single_message_tx. It is not working at all, I see nothing coming into the CAN analyzer.

The things that I have modified in the demo are:

- CAN FD disabled

- Arbitration bit rate and data bit rate set to 500kbps

- The TxBufElement is modified to be a Can classic message as follows

"Also, need to make sure that there is no logic level issue when you connect STB to 5V, but other logic level RXD/TXD is 3.3V."

I have tried to tie STB to VIO(3.3V) and VCC(5V) and get the same results, nothing.

I am using PA12 as the TX pin, connected to the TX pin of the TCAN device, and PA13 as the RX pin, connected to the RX pin of the TCAN device.

I am at a complete loss as how to make this work as I am using two devkits and example software, I don't even understand where it could fail...

I have also tried the same test setup with two different LP-MSPM0G3507 devkits and get the same results, so I don't beleive it is a hardware fault. The TCAN seems to be working fine as it decodes messages sent from the IXAAT usb to CAN converter with no issues.

Here are the Init and Config parameters used during intialization, do you see any errors on this side?

static const DL_MCAN_InitParams gMCAN0InitParams= {

/* Initialize MCAN Init parameters.    */
    .fdMode            = false,
    .brsEnable         = false,
    .txpEnable         = false,
    .efbi              = false,
    .pxhddisable       = false,
    .darEnable         = false,
    .wkupReqEnable     = true,
    .autoWkupEnable    = true,
    .emulationEnable   = true,
    .tdcEnable         = true,
    .wdcPreload        = 255,

/* Transmitter Delay Compensation parameters. */
    .tdcConfig.tdcf    = 10,
    .tdcConfig.tdco    = 6,
};

static const DL_MCAN_ConfigParams gMCAN0ConfigParams={
    /* Initialize MCAN Config parameters. */
    .monEnable         = false,
    .asmEnable         = false,
    .tsPrescalar       = 15,
    .tsSelect          = 0,
    .timeoutSelect     = DL_MCAN_TIMEOUT_SELECT_CONT,
    .timeoutPreload    = 65535,
    .timeoutCntEnable  = false,
    .filterConfig.rrfs = true,
    .filterConfig.rrfe = true,
    .filterConfig.anfe = 1,
    .filterConfig.anfs = 1,
};

No issue seen at my side.

Francis Poirier said:

- The TxBufElement is modified to be a Can classic message as follows

No issue.

Francis Poirier said:

I am using PA12 as the TX pin, connected to the TX pin of the TCAN device, and PA13 as the RX pin, connected to the RX pin of the TCAN device.

Correct.

Make sure you assign these two pins in syscfg pinmux in mcan.

Francis Poirier said:

Here are the Init and Config parameters used during intialization, do you see any errors on this side?

No issue seen here.

Are you running the single_message_tx example code? I see the ID is changing in your screenshot which the code does not do right?

while in debug I can see using breakpoints that the interrupt for the PB is trigerred and that the transmit code is executed. Inspecting the txMsg structure i get the following (for CAN ID 0x04):

{"id":1048576,

"rtr":0,"xtd":0,

"esi":0,"dlc":1,

"brs":0,

"fdf":0,

"efc":1,

"mm":170,

"data":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255,255,255,255,255,255,255,255,255,255,255,255,31,10,0,0]}

and still no output at all from the MSPM0.

The pins are correctly assigned in sysConfig.

Make sure that you connect correct Tx-Tx, Rx-Rx between M0 and TCAN.

If one setup is not work, try to switch them.

If Tx and Rx is connected with wrong way, there won't be any signal on the Tx PIN.

Francis Poirier said:

while in debug I can see using breakpoints that the interrupt for the PB is trigerred and that the transmit code is executed. Inspecting the txMsg structure i get the following (for CAN ID 0x04):

This is only hthe RAM buffer, these data will write to CAN RAM for CAN core usage.

Once CAN RAM is written, and Tx require is set, MCAN will send these data to Tx pin.

Francis Poirier said:

Are you running the single_message_tx example code? I see the ID is changing in your screenshot which the code does not do right?

Both [single_message_tx ] and [mcan_application] is test at  my side.

For [single_message_tx], you need to push button to trigger can send, do you push the button?

Glad to hear your issue resolved~ thanks for the feedback~