Hello, I have a MCP2515 board like this: [mcp2515] I connected it to an Arduino nano and I tried to use coryjfowler's MCP_CAN_lib, but without any success. The CAN Bus is from a Stiebel Eltron heat pump which I would like to monitor. For debugging I have another professional tool which works fi…

Hopefully it is as easy as changing the crystal frequency. if(CAN0.begin(MCP_ANY, CAN_20KBPS, MCP_16MHZ) == CAN_OK) Should probably be if(CAN0.begin(MCP_ANY, CAN_20KBPS, MCP_8MHZ) == CAN_OK) Those boards use an 8MHz crystal. See the 8.000 on the silver can? The shields tend to be 16MHz. This …

Huh, super strange. I would expect the opposite if it were the microcontroller speed as I believe the ESP8266 has a faster crystal and execution speed. Fortunately I recently acquired some of those, so I will see if I can recreate this issue and get back with you.

I am unfortunately unable to recreate the issue with the information I have, everything seems to work fine. I will note that at 20kbps, you will need to increase the send timeout value to avoid the error associated with it. Sending these messages at some speeds to match what I seen from your scree…

Hi Cory, thanks a lot for your support :slight_smile: I guess it has something to do with the number range of a variable or something similar. I guess it compiles differently for the Arduino nano than for the ESP8266. But that's just my feeling without being a professional programmer. I'm doing…

By the way, I don't think it matters, but the Arduino nano has 5V GPIOs and the ESP8266 has only 3.3V GPIOs. I think it does not matter because the ESP already receives data. I also do not think that the pins I use matter. [20200902_235628] [20200902_235714] [20200902_235643] I found the sche…

I was reading that the ESP8266 has 5V tolerant IO. I have the CAN interface on my setup powered via VIN which is tied to USB 5V. I tried using a 3V3 pin out of curiosity and the CAN transceiver on the board would not see any of the traffic I was sending, but the library was talking to the MCP2515 …

In theory the transceiver on the Niren board is supposed to be the 5v version and therefore shouldn't work at all with 3.3v as there is an under voltage shutdown feature in the chip. However, the worldwide shortage of CAN related chips has resulted in a flood of fake transceivers that have characte…

I bought this board in 2020, not recently. The board works fine with 3,3V so far. Maybe I exchange the ESP8266 to a ESP32 to check if it works differently. Or I can add a level shifter to see if this changes anything. Best regards, Chris

@mikb55 , that is super useful info! I know the NiRen boards I have predate the pandemic which could explain the differences we see here.

Would you be willing to try the NiRen board supplied with 5v first?

Simply swap the vcc Pin of the niren Board from 3,3V to Vin on the nodemcu, or something more?

Trying to read CAN Bus with MCP2515 and coryjfowler MCP_CAN_lib

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Trying to read CAN Bus with MCP2515 and coryjfowler MCP_CAN_lib

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