Running CAN-BUS Sample with different shield (NRF52840DK & Seeed CAN BUS Shield V2.0)

[ejromero2]

Hi All, 

Im very new to this how firmware space and would love some help.

Currently i have a NRF52840 DK Board with a Seeed Canbus shield. (CAN-BUS Shield V2.0 | Seeed Studio Wiki)

From what i have read is very similar to the DFROBOT CanBus Shield. (Only changing the default pinout for the CS from D10 to D9)

- I have been able to succesfully comple and flash the firmware but i get the following error :

Error starting CAN controller [-5]

I have tried modifying the dfrobot_can_bus_v2_0.overlay to make it work with my seeed shield.  (changing the CS-GPIOS to 15 (D9) instead of 16 (D10).

The error remains the same, and i dont really know how to get a little bit more information to progress on this.

Im trying to run this sample: zephyr/samples/drivers/can/counter at main · zephyrproject-rtos/zephyr (github.com)

[ovrebekk]

Hi Efrain

Error -5 means there is some communication issue with the board. 

Do you know if the board is able to run at 3V? 
The supply and GPIO voltage of the nRF52840DK is around 3V, while many Arduino shields require 5V supply. 

Have you probed the SPI lines to see if there is any activity when the code runs? 
If not it could point to some configuration issue in your project. 

Could you share the overlay with me? 

Best regards
Torbjørn

[ejromero2]

Hi there,

Thanks for the answer:

I only changed the cs-pios to 15 to make it in line with the seeed information.

/*
 * Copyright (c) 2019 Karsten Koenig
 *
 * SPDX-License-Identifier: Apache-2.0
 */

&arduino_spi {
	status = "okay";
	cs-gpios = <&arduino_header 15 GPIO_ACTIVE_LOW>; /* D9 */

	mcp2515_dfrobot_can_bus_v2_0: can@0 {
		compatible = "microchip,mcp2515";
		spi-max-frequency = <1000000>;
		int-gpios = <&arduino_header 8 GPIO_ACTIVE_LOW>; /* D2 */
		status = "okay";
		reg = <0x0>;
		osc-freq = <16000000>;
		bus-speed = <125000>;
		sjw = <1>;
		sample-point = <875>;

		can-transceiver {
			max-bitrate = <1000000>;
		};
	};
};




/ {
	chosen {
		zephyr,canbus = &mcp2515_dfrobot_can_bus_v2_0;
	};
};

I get the following logging info:

[00:00:00.476,654] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
uart:~$ Error starting CAN control--- 431 messages dropped ---
[00:00:00.499,145] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.499,176] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.499,206] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.499,237] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.499,389] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.499,420] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.499,481] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.499,511] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.499,542] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.499,572] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.499,603] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.499,755] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.499,786] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.499,847] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.499,877] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.499,908] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.499,938] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.499,969] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.500,122] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.500,152] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.500,213] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.500,244] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.500,274] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.500,305] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.500,335] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.500,518] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.500,549] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.500,579] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.500,610] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.500,640] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.500,671] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.500,701] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.500,885] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.500,915] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.500,946] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.500,976] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.501,037] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.501,037] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.501,068] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.501,251] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.501,281] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.501,312] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.501,342] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.501,403] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.501,403] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.501,434] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.501,617] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.501,647] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.501,678] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.501,708] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.501,770] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.501,770] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.501,800] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.501,983] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.502,014] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.502,075] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.502,105] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.502,136] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.502,166] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.502,197] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.502,349] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.502,410] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.502,441] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.502,471] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.502,502] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.502,532] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.502,563] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.502,777] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.502,807] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.502,838] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.502,868] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.502,899] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.502,929] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.502,960] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.503,112] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.503,173] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.503,204] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.503,234] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.503,265] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.503,295] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.503,326] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.503,540] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.503,570] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.503,601] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.503,631] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.503,662] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.503,692] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.503,723] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.503,875] <dbg> spi_nrfx_spi: spi_context_buffers_setup: tx_bufs 0x20004838 - rx_bufs 0x20004840 - 1
[00:00:00.503,936] <dbg> spi_nrfx_spi: spi_context_buffers_setup: current_tx 0x20004848 (2), current_rx 0x20004858 (2), tx buf/len 0x20004834/2, rx buf/len (nil)/2
[00:00:00.503,967] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/1
[00:00:00.503,997] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len 0x2000487f/1
[00:00:00.504,058] <dbg> spi_nrfx_spi: spi_context_update_tx: tx buf/len (nil)/0
[00:00:00.504,089] <dbg> spi_nrfx_spi: spi_context_update_rx: rx buf/len (nil)/0
[00:00:00.504,089] <dbg> spi_nrfx_spi: finish_transaction: Transaction finished with status 0
[00:00:00.504,150] <err> can_mcp2515: Timeout trying to set MCP2515 operation mode
[00:00:00.504,180] <err> can_mcp2515: Failed to set the mode [-5]
uart:~$

im not quite sure about the power question.  i have tried to put some extra sensors on the 3.3 output of the shield and that sensor works just fine. (but then again im guessing is just the direct line from the nrf).

[ejromero2]

Almost there then :)

[ovrebekk]

Fingers crossed I will be able to reproduce the issue, and find a solution ;)

Did you discover anything else in the mean time that might be helpful to know? 

Best regards
Torbjørn

[ejromero2]

No really. to be honest i stopped trying because my results were not the same and to me it seems its related to spi communication and i dont really know how to properly debug it.

[ovrebekk]

Hi

Ok, thanks for the update. I will get back to you next week then, once I have had some time to take a look. 

Regards
Torbjørn

[ejromero2]

hi there... any updates?

[ovrebekk]

Hi 

Sorry for not getting back to you. Even after so long in Nordic I keep overestimating the time I have available for these kinds of things....

My next couple of weeks are pretty packed, but I will set aside some time for evaluating this the last month of May. I can't promise I will get to the bottom of it in the time available, but I will give it a go at least. I will send you an update once I start on the tests. 

Best regards
Torbjørn

[ejromero2]

thanks a lot. im subscribed to the thread but ill ping back :D

[ovrebekk]

Sounds good, please reach out if you don't hear anything by that time

[ovrebekk]

Hi again

As it happens I had some available time and decided to run a quick test with the Seeed Can-bus v2 shield. As we discussed earlier the voltage is definitely incorrect, but the shield seems to work fine when I cut the 5v line and make a short between the 3V3 and 5V signals on the Shield. 

With this hack I can get the counter sample to run without any apparent issues, at least in the default loopback mode. 

I use the following overlay:

&arduino_spi {
	status = "okay";
	cs-gpios = <&arduino_header 15 GPIO_ACTIVE_LOW>; /* D9 */

	mcp2515_dfrobot_can_bus_v2_0: can@0 {
		compatible = "microchip,mcp2515";
		spi-max-frequency = <1000000>;
		int-gpios = <&arduino_header 8 0x1>; /* D2 */
		status = "okay";
		reg = <0x0>;
		osc-freq = <16000000>;
		bus-speed = <125000>;
		sample-point = <875>;

		can-transceiver {
			max-bitrate = <1000000>;
		};
	};
};

/ {
	chosen {
		zephyr,canbus = &mcp2515_dfrobot_can_bus_v2_0;
	};
};

My 3.3V hack looks like this:

Best regards
Torbjørn

[smh02]

Hi everyone!

I would like to know if you were able to communicate with another device via CAN using normal mode?

I am working with the same board and the CAN BUS Seeed V2.0 shield so I followed the steps.

I included the overlay you mentioned and also did the 3.3V hack as you indicated. With this I was able to make the Loopback mode work without problems sending and receiving frames as you can see below:

[00:00:08.402,130] <inf> main: -------------------------
[00:00:08.402,160] <inf> main: Initializing CAN bus
[00:00:08.402,160] <inf> main: Asserting device ready.
[00:00:08.402,191] <inf> main: CAN: Device can@0 ready.
[00:00:08.402,191] <inf> main: -------------------------
[00:00:08.402,221] <inf> main: Enabling MODE LOOPBACK.
[00:00:08.402,221] <inf> main: MODE LOOPBACK.
[00:00:08.402,221] <inf> main: -------------------------
[00:00:08.402,252] <inf> main: Trying to set bitrate.
[00:00:08.402,557] <inf> main: Bitrate set.
[00:00:08.402,587] <inf> main: -------------------------
[00:00:08.402,587] <inf> main: Adding reception filter
[00:00:08.402,587] <inf> main: Before adding reception filter.
[00:00:08.402,618] <inf> main: RX filter added successfully. Filter ID: 0
[00:00:08.402,618] <inf> main: -------------------------
[00:00:08.402,618] <inf> main: Trying to start CAN.
[00:00:08.402,832] <inf> main: CAN started
[00:00:08.402,832] <inf> main: -------------------------
[00:00:08.402,832] <inf> main: Waiting for CAN frame
[00:00:09.402,923] <inf> main: Sending CAN frame with ID: 0x7df, DLC: 8
[00:00:09.403,228] <inf> main: CAN frame sent
[00:00:09.403,228] <inf> main: ** ** ** ** ** ** ** **
[00:00:09.403,808] <inf> main: Message sent successfully - Sender: Sender 1
[00:00:09.403,808] <inf> main: tx_callback executed
[00:00:11.403,320] <inf> main: Waiting for CAN frame
[00:00:12.403,472] <inf> main: Sending CAN frame with ID: 0x7df, DLC: 8
[00:00:12.403,747] <inf> main: CAN frame sent
[00:00:12.403,778] <inf> main: ** ** ** ** ** ** ** **
[00:00:12.404,296] <inf> main: Message sent successfully - Sender: Sender 1
[00:00:12.404,327] <inf> main: tx_callback executed

However, when I set the normal mode to receive or send frames I get the same error <err> main: Sending failed [-11] as you can see:

[00:00:08.434,112] <inf> main: -------------------------
[00:00:08.434,143] <inf> main: Initializing CAN bus
[00:00:08.434,143] <inf> main: Asserting device ready.
[00:00:08.434,173] <inf> main: CAN: Device can@0 ready.
[00:00:08.434,173] <inf> main: -------------------------
[00:00:08.434,204] <inf> main: Enabling MODE NORMAL.
[00:00:08.434,204] <inf> main: MODE NORMAL.
[00:00:08.434,204] <inf> main: -------------------------
[00:00:08.434,234] <inf> main: Trying to set bitrate.
[00:00:08.434,539] <inf> main: Bitrate set.
[00:00:08.434,570] <inf> main: -------------------------
[00:00:08.434,570] <inf> main: Adding reception filter
[00:00:08.434,570] <inf> main: Before adding reception filter.
[00:00:08.434,600] <inf> main: RX filter added successfully. Filter ID: 0
[00:00:08.434,600] <inf> main: -------------------------
[00:00:08.434,600] <inf> main: Trying to start CAN.
[00:00:08.434,814] <inf> main: CAN started
[00:00:08.434,814] <inf> main: -------------------------
[00:00:08.434,814] <inf> main: Waiting for CAN frame
[00:00:09.434,906] <inf> main: Sending CAN frame with ID: 0x7df, DLC: 8
[00:00:09.435,211] <inf> main: CAN frame sent
[00:00:09.435,211] <inf> main: ** ** ** ** ** ** ** **
[00:00:11.435,302] <inf> main: Waiting for CAN frame
[00:00:12.435,485] <inf> main: Sending CAN frame with ID: 0x7df, DLC: 8
[00:00:17.435,607] <err> main: Sending failed [-11]
[00:00:17.435,638] <inf> main: ** ** ** ** ** ** ** **
[00:00:19.435,729] <inf> main: Waiting for CAN frame
[00:00:20.435,913] <inf> main: Sending CAN frame with ID: 0x7df, DLC: 8
[00:00:25.436,035] <err> main: Sending failed [-11]
[00:00:25.436,065] <inf> main: ** ** ** ** ** ** ** **

This is the code that i'm using:

#include <zephyr/drivers/can.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(main);

void tx_callback(const struct device *dev, int error, void *user_data)
{
    char *sender = (char *)user_data;

    if (error != 0) {
        LOG_ERR("Sending failed [%d] - Sender: %s", error, sender);
    } else {
        LOG_INF("Message sent successfully - Sender: %s", sender);
    }
    LOG_INF("tx_callback executed");
}

int send_function(const struct device *can_dev)
{
    struct can_frame frame = {.flags = 0, .id = 0x7df, .dlc = 8, .data = {0x02, 0x01, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00}};

    LOG_INF("Sending CAN frame with ID: 0x%x, DLC: %d", frame.id, frame.dlc);

    return can_send(can_dev, &frame, K_MSEC(5000), tx_callback, "Sender 1");
}

void rx_callback_function(const struct device *dev, struct can_frame *frame, void *user_data)
{
    char *sender = (char *)user_data;

    LOG_INF("Received CAN frame - Sender: %s", sender);
    LOG_INF("ID: 0x%x, DLC: %d", frame->id, frame->dlc);
    LOG_HEXDUMP_INF(frame->data, frame->dlc, "Data: ");
}

int main(void)
{
    LOG_INF("CanBus-OBD2 samplev11");
    int ret;
    k_sleep(K_MSEC(8000));

    LOG_INF("-------------------------");

    LOG_INF("Initializing CAN bus");

    const struct device *const can_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_canbus));

    LOG_INF("Asserting device ready.");
    if (!device_is_ready(can_dev)) {
        LOG_ERR("CAN: Device %s not ready.", can_dev->name);
        return 0;
    }
    LOG_INF("CAN: Device %s ready.", can_dev->name);

    LOG_INF("-------------------------");

    LOG_INF("Enabling MODE LOOPBACK.");
    ret = can_set_mode(can_dev, CAN_MODE_LOOPBACK);
    if (ret != 0) {
        LOG_ERR("Error setting CAN mode [%d]", ret);
        return 0;
    }
    LOG_INF("MODE LOOPBACK.");

    LOG_INF("-------------------------");

    LOG_INF("Trying to set bitrate.");
    ret = can_set_bitrate(can_dev, 500000);
    if (ret != 0) {
        LOG_ERR("Error setting CAN bitrate [%d]", ret);
        return 0;
    }
    LOG_INF("Bitrate set.");

    LOG_INF("-------------------------");
    LOG_INF("Adding reception filter");

    const struct can_filter my_filter = {
        .flags = CAN_FILTER_DATA, .id = 0x7E8, .mask = CAN_STD_ID_MASK};
    int filter_id;

    char *callback_arg = "Callback argument";

    LOG_INF("Before adding reception filter.");
    filter_id = can_add_rx_filter(can_dev, rx_callback_function, callback_arg, &my_filter);
    if (filter_id >= 0) {
        LOG_INF("RX filter added successfully. Filter ID: %d", filter_id);
    } else {
        LOG_ERR("Failed to add RX filter. Error code: %d", filter_id);
    }
    LOG_INF("-------------------------");

    LOG_INF("Trying to start CAN.");
    ret = can_start(can_dev);
    if (ret != 0) {
        LOG_ERR("Error starting CAN controller [%d]", ret);
        return 0;
    }
    LOG_INF("CAN started");

    LOG_INF("-------------------------");

    while (1) {
        LOG_INF("Waiting for CAN frame");
        k_sleep(K_MSEC(1000));
        ret = send_function(can_dev);
        if (ret != 0) {
            LOG_ERR("Sending failed [%d]", ret);
        } else {
            LOG_INF("CAN frame sent");
        }
        LOG_INF("** ** ** ** ** ** ** **");
        k_sleep(K_MSEC(2000)); // Intervalo de 2 segundos entre envíos
    }

    return 0;
}

Just in case, this is my build configuration:

And my prj.config

CONFIG_POLL=y
CONFIG_CAN=y
CONFIG_SPI=y
CONFIG_CAN_MCP2515=y
CONFIG_CAN_INIT_PRIORITY=80
CONFIG_CAN_MAX_FILTER=5

CONFIG_SHELL=y
CONFIG_CAN_SHELL=y
CONFIG_DEVICE_SHELL=y

CONFIG_GPIO=y
CONFIG_STATS=y
CONFIG_STATS_NAMES=y
CONFIG_STATS_SHELL=y
CONFIG_CAN_STATS=y

CONFIG_RTT_CONSOLE=n

CONFIG_LOG=y
CONFIG_CAN_LOG_LEVEL_DBG=y
CONFIG_SPI_LOG_LEVEL_DBG=n

CONFIG_PRINTK=y
CONFIG_CONSOLE=y

Any ideas? I really don't know if I am missing a file to include in the construction of my application. Also I was wondering if I could include a logic level converter (TXS0108E) to verify if the reason why i can't communicate is due to the difference of voltages in the SPI communication.

I would be very grateful if you could help me :)