Connecting nrf5340dk to MCP2515 CAN bus shield

RE: Connecting nrf5340dk to MCP2515 CAN bus shield

Simonr — Thu, 12 Sep 2024 13:14:39 GMT

Glad to hear you got the SPI up and running!

The VREGHOUT can only be set with the UICR bits as per line 16372 in nrf5340_application_bitfields.h at ...\v2.7.0\modules\hal\nordic\nrfx\mdk\nrf5340_application_bitfields.h. There is no specific config for this from what I can find. And the maximum VREGH output voltage is indeed 3.3V.

Best regards,

Simon

RE: Connecting nrf5340dk to MCP2515 CAN bus shield

Alexander Astely — Wed, 11 Sep 2024 08:33:40 GMT

Thank you for the tips,

I ended up setting the VREGHVOUT to 3.3 V using the following command;

nrfjprog -s <serial_number> --memwr 0x00FF8010 --val 5

(Is there any way to do this in the project config rather than the command line?)

However, when looking at the table here; https://docs.nordicsemi.com/bundle/ps_nrf5340/page/chapters/uicr/doc/uicr.html#register.VREGHVOUT it seems the maximum voltage for the GPIO voltage is 3.3V or am I missing something?

Anyways, I ended up setting the VREGHVOUT to 3.3 V and connecting the SPI to the MCP2515 directly without the logic level converter and I managed to get it working.

Thank you for the help!

RE: Connecting nrf5340dk to MCP2515 CAN bus shield

Simonr — Wed, 07 Aug 2024 07:41:55 GMT

The GPIO electrical specification of the nRF5340 PS shows what the supported input and output voltages are. I believe the "default" on the DK is 3V.

In your image it seems like the I2C converters are flipped, but either way I think this is likely to mess up the SPI data you're sending since the voltage level changes, wouldn't it be better to run the nRF5340 in the VDDH to run the GPIO voltage at higher voltages in the high drive and voltage mode. For more detailed information, you can refer to the GPIO Electrical Specification and Regulator Control sections in the nRF5340 Product Specification.

Best regards,

Simon

RE: Connecting nrf5340dk to MCP2515 CAN bus shield

Alexander Astely — Tue, 06 Aug 2024 14:32:25 GMT

Thank you for the quick reply. I have attached a higher quality image of the setup.

So the bidirectional logic level shifter is just used because the Arduino has a voltage level of 5V while the nrf5340DK has a lower voltage level (how is the voltage level of the GPIO pins set on the nrf5340dk? I think it is 1.8V or 3.3V). So right now the low voltage (LV) is connected to the VDD pin of the nrf5340DK and the high votlage (HV) is connected to the 5V pin of the nrf5340DK. The arduino is connected to the 5V pin.

Shouldn't it be SPI since I am trying to interface with the MCP2515 CAN Bus Shield via SPI?

devzone.nordicsemi.com/.../Untitled-drawing.pdf

RE: Connecting nrf5340dk to MCP2515 CAN bus shield

Simonr — Tue, 06 Aug 2024 12:20:07 GMT

The error message you see refers to an input/output error, so I assume the connections somewhere in this setup is incorrect. Do you have a higher resolution image of the setup you uploaded, as zooming in on it I'm not able to read what the pins on the sensor is. Also, what voltage are all parts running on here? Does the nRF53 DK, Arduino, MCP2515 and I2C converter all run at the same GPIO voltage?

Also, it seems to me like you're mixing and I2C and SPI here, since the overlay file uses SPI, while should use TWI.

Best regards,

Simon