MCP2515 CAN0(27); // (mcp2515 library)
or
MCP_CAN CAN0(27); // (mcp_can library)

glad to hear you got it working.

@TLS : thank you for figuring out the issue and letting us know.

Thanks
Felix

no, not EN, but pin 15 on the M-Bus (which on M5Core2 is pin 2). Please also see the COMMU schematic here. Pin 15 is labelled CAN_INT.

Thanks
Felix

I need the CAN bus, but can't seem to get it to work.

What pins did you find work for this device in order to access the CAN bus?

Note, I also have the CAN I2C module that I am also trying to use, but can't get it to work either.

the GPIO information regarding M5Core2 UART2 is correct here - check section M5Core2 M-BUS Schematic diagram and Section M5Core2 BUS(compared to M5Stack). M5Stack even has linked my comparison sheet. Yay!

Where exactly did you find the incorrect information? Never mind - found it. The GPIO list in the Espressif document you mentioned shows each pin and its possible (default) functionality. Luckily though ESP32 has a GPIO Matrix which allows to reassign almost any pin to any function. Unfortunately GPIO16 / GPIO17 are required for PSRAM and therefore M5Stack was forced to assign two other GPIOs for UART2.

BTW: GPIO7, GPIO8, GPIO9, GPIO10, GPIO16, GPIO17 are used for PSRAM.

Thanks
Felix

In general, I would like at least 2 UART Rx channels. The M5 Stack comes with 3x UARTS according to the spec sheet.

From another internet source on the subject of UART and ESP32, I found the following:

• U0UXD is used to communicate with the ESP32 for programming and during reset/boot.
• U1UXD is unused and can be used for your projects. Some boards use this port for SPI Flash access though
• U2UXD is unused and can be used for your projects.

So, I thought, easy-peasy....I can count on being able to use UART1 and 2 - the M5 Stack (Core2) should be able to manage this, correct?
(I don't plan attaching any GPS-Module, etc, so....2x UARTs should be the minimum available)

But your having mentioned that the pin layout is different makes we question how reliable the M5 documentation really is (?).

Appreciate any feedback...also bookmarked your pinning page, thanks.

I agree, it can be a bit frustrating at times but on the bright side you will probably learn some new skills, like reading and understanding schematics.
I am positive you'll figure it out.

Of course, I have been playing with Arduino and ESP8266 / 32 for 3 years and several years ago with the PIC16 ... and all my pleasure is to learn and to discover.
I have already read many schematics and created myself some PCBs for my project.
Thank you Felix

from my experience in general M5Stack devices and modules are simply stackable without any issues but over time some GPIOs needed to be rearranged in later products to accommodate for newer functions etc. which can cause issues like you most likely are encountering right now.

Most modules have been created for M5Stack devices (Gray, Fire etc.) and while they still can be used with the newer M5Core2 device some of them might require some modifications (hardware or software).

I agree, it can be a bit frustrating at times but on the bright side you will probably learn some new skills, like reading and understanding schematics.

I am positive you'll figure it out.

Cheers
Felix

@felmue said in Core 2 and COMMU:

just to be clear. You are able to flash your M5Core2 as long as the COMMU module is not connected (stacked) to it, correct?

Yes that's right.

About COMMU jumpers it's not very easy to find information about it. Not easy also to find them on the board whithout a good magnifying glass. I found a picture on the net more easy to read.
And when I bought the COMMU, I didn't think I had to understand the schematic. I thought it was more plug & play as the presentation suggests.
Anyway thank you very much for your help. I will persevere.
Didier

just to be clear. You are able to flash your M5Core2 as long as the COMMU module is not connected (stacked) to it, correct?

It looks like when the COMMU module is connected (stacked) it blocks / uses the default UART pins which then prevent the download.

Have you verified the COMMU jumpers J6, J7, J9 and J10 are set correctly to use UART2? (The default UART is required for the firmware download.)

Please note that compared to M5Stack (Gray, Fire, etc.) in M5Core2 UART2 pins have changed from GPIO16/GPIO17 to GPIO13/GPIO14 so you might need to adapt your code accordingly.

Thanks
Felix

Start Burn

--chip esp32 --port COM3 --baud 921600 --before default_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size detect 0x1000 D:\F - Locoduino\M5Stack\M5Burner\packages\fw\core\UIFlow_Core2-v1.7.0-core2.bin

esptool.py v2.5.0
Serial port COM3
Connecting...
.

Chip is ESP32D0WDQ6 (revision 1)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse
MAC: 84:cc:a8:60:ed:ac
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 921600
Changed.
Configuring flash size...
Warning: Could not auto-detect Flash size (FlashID=0xffffff, SizeID=0xff), defaulting to 4MB

A fatal error occurred: File D:\F - Locoduino\M5Stack\M5Burner\packages\fw\core\UIFlow_Core2-v1.7.0-core2.bin (length 8376320) at offset 4096 will not fit in 4194304 bytes of flash. Use --flash-size argument, or change flashing address.

Burn Failed

I try with the USB cable delivered with Core 2 or one of mine, nothing change.
Didier