trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Syed Maysum Abbas Zaidi — Wed, 22 Jul 2026 08:07:40 GMT

Hi Vivek,

Thanks for the details, trying three modules with the same result tells us the modules themselves are fine, and your loopback test passing tells us the ESP32's CAN chip and wiring are fine too. So I think the problem isn't the parts or your code, it's on the physical bus side, where the signal actually goes out on the CANH/CANL wires.

Normally on a working bus, CANH and CANL both sit near 2.5 V when idle and move together when a message is sent. Yours show CANH normal at 2.23 V but CANL stuck low at 1.38 V and not moving, that's the sign of a CAN transceiver that isn't being driven properly, which most likely comes down to power. As per my understanding each board has its own CAN transceiver, and both need a solid 3.3 V to work. Right now you're powering the modules from the ESP32's 3.3 V pin (Correct me if I am wrong) , which seems not able to hold a steady voltage for both so the nRF side transceiver is likely running under powered.

For testing purpose, could you try powering both CAN modules from a separate, steady 3.3 V supply instead of the ESP32 pin, and keep all the grounds connected together. Then run your normal test again and watch whether CANH/CANL start moving. Let me know how it goes and we'll take it from there.

Best regards,
Syed Maysum

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vivek01 — Mon, 20 Jul 2026 20:42:02 GMT

Hi syed,

- one thing you have to know that i'm using seengreat rs485 dual CAN Bus module and i bought three of them, two from amazon and one from company's website cuz at first i thought there is something wrong with the CAN chip but now i still get the same result. i don't know what's wrong with this. please help me, i'm stuck in this situations from almost last three months.

- I gave the VCC (power) from the esp32 to CAN module and it's 3.3v cuz i connect to 3.3v pin in esp32 so i didn't give the VCC (power) from nrf and i connect the nrf GND to esp32 GND.

- When i run esp32 code, CANH = 2.23v and CANL = 1.38v and it's stays where they are like it's not moving.

- I run ESP32's MCP2515 in loopback mode and here is the output

thanks

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Syed Maysum Abbas Zaidi — Mon, 20 Jul 2026 09:11:10 GMT

Hi Vivek,

Thanks for the detailed measurements, Vidar is not available so I am taking up your case.

Your ESP32 shows TEC=128 (TXEP), which just means it's sending but never getting an acknowledgement back. Your nRF9160 shows REC=0 and no received frames, meaning it's not hearing anything on the bus at all. If the nRF were actually receiving your messages but not acknowledging them, I'd expect its REC counter to climb or at least a received frame to show up, but both stay flat. So I think this isn't a "normal mode / not acknowledging" issue, and it's not the Zephyr interrupt handling or the MCP2515 registers. The frames just aren't reaching the nRF's CAN chip. I believe that usually means the problem is on the hardware side, not the code.

One thing worth knowing is the 60 Ω you measured only confirms the two termination resistors are connected, it doesn't confirm the nRF's CAN transceiver is actually powered. A transceiver with no power still reads 60 Ω.

Could you check a couple of things for me:

- Measure the VCC (power) pin of the CAN module on the nRF side, it should be 3.0-3.6 V.
- With a scope or meter, watch CANH and CANL while the ESP32 is sending, you should see them move. If they stay flat, the signal isn't getting onto the bus.
- If possible, run the ESP32's MCP2515 in loopback mode to confirm that board is fine on its own.

Once we know the transceiver is properly powered and the bus lines are actually moving, the sample code should work. Send over what you find and we'll take the next step from there.

Best regards,
Syed Maysum

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vivek01 — Tue, 14 Jul 2026 01:35:37 GMT

i have verified one more time that both mcp2515 modules use 16 MHz crystals, both use SN65HVD230 transceivers, CANH/CANH, CANL/CANL, common ground, 60 ohm measured between CANH and CANL with power off, zephyr reports CAN started successfully with State=0 TEC=0 REC=0, the esp32 MCP2515 initializes successfully but reaches TEC=128, EFLG=0x15 while REC=0.

does this pattern suggest that the nRF9160 MCP2515 is not acknowledging frames despite being in normal mode or would you recommend checking additional MCP2515 registers or the INT handling in the Zephyr sample?

here is screenshot of the output from both nrf and the esp32.

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vidar Berg — Wed, 01 Jul 2026 06:41:02 GMT

These driver files are already included in your build when you have the mcp2515 node with the "microchip,mcp2515" binding included in your devicetree. Your application should only need to work with the top level Zephyr CAN driver API as demonstrated by the sample code. Instead of changing the code, I would recommend you try to debug the existing sample code and find out what the errors from the log indicate.

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vivek01 — Tue, 30 Jun 2026 02:37:11 GMT

Hi vidar,

sorry to bother you but one thing i notice in my project file/ main.c, i didn't use zephyr/drivers/can_mcp2515.h and can_mcp2515.c so do i need to compile those files into main.c or do i need to use other files to use for this concept?

thanks

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vivek01 — Sat, 27 Jun 2026 01:09:36 GMT

Hi vidar,

i connected level shifter with can bus moduler and nRF9160 so my connections are like i connected HV = 3.30v and GND = GND so i measured before flash the board all HV1 to HV5 are became 3.30v and at the other side LV = nrf 1.80v and GND = GND so i measured before flash the board all LV1 to LV5 are became 1.80v and i connect the HV1 MISO CAN to LV1 MISO NRF(PO=12), HV2 MOSI CAN to LV2 MOSI NRF(PO=11), HV3 SCK CAN to LV3 SCK NRF(PO=13), HV4 CS CAN to LV4 CS NRF(PO=25), HV5 INT CAN to LV5 INT NRF(PO=17) in level shifter.

but when i flash the nRF9160 and ESP32, i didn't get succeeded and then i measured nRF pins after flash the board and sees that MOSI and SCK pins voltage drop down to 0.01 so what's that mean and please tell me that what should i have to do to get successful in this.

thanks

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vidar Berg — Wed, 17 Jun 2026 06:45:41 GMT

You have circled around the switch in your picture. You just need to remove the protective tape before you can switch it to the 3v position. But as stated in the linked documentation, this changes the IO voltage to 3.0v, not 3.3v as required in your case.

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vivek01 — Wed, 17 Jun 2026 01:23:12 GMT

Hi vidar,

can you tell me that why my nRF9160DK have not a SW9 switch to control the VDD power to 3.3v from 1.8v. the nordic document said that i can control the IO power 1.8v to 3.3v from SW9 switch that is located just beside the board power switch. actually SW9 is soldered in my board so i can't control it as a switch.

here is my board number and the pictures of the SW9 switch.

thanks

vivek

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vidar Berg — Sat, 13 Jun 2026 09:40:18 GMT

Hi Vivek,

I looked at the specification for the CAN module and saw that it required a min. voltage of 3.3v. The VDD IO configuration DK is covered in the nRF9160 DK User Guide here: https://docs.nordicsemi.com/r/bundle/ug_nrf9160_dk/page/ug/nrf91_dk/hw_description/power_sources_vdd.html. From this you can see that you will either need an external VDD IO supply to reach 3.3v, or use an external level shifter to communicate with the module. It is also important that you carefully review the specification for the module you are using to see if there may be other issue apart from the incompatible voltage level.

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vivek01 — Fri, 12 Jun 2026 21:39:32 GMT

Hi Vidar,

i measured PO. 25(CS) = 1.80v and PO. 17(INT) = 2.58v in nRF9160DK and i measured PO.5(CS) = 3.30v and PO.4(INT) = 3.30v in esp32. so you tell me that the nRF9160 DK is configured to use 1.8v by default, which is too low then can you please tell me, what's the solution for this to send and receive the data with this model.

thanks

vivek

RE: trying to send and receive the data through can bus moduler using with nrf9160 and esp32 controller (using SPI)

Vidar Berg — Fri, 12 Jun 2026 13:36:13 GMT

Hello Vivek,

Please verify if the IO voltage used by both the esp and nrf is supported by the module. Note that the nRF9160 DK is configured to use 1.8v by default, which is too low.

Best regards,

Vidar