https://randomnerdtutorials.com/esp-now-two-way-communication-esp32/

I run a small collection of M5Stack components communicating in ESP_NOW.
A Core reading a Stamp for remote temp, the Stamp receives commands to operate a servo motor from the Core.

The M5Stack JoyC controlling a BugC unit is a good example as well, in the M5Stack examples GutHub.
Or my own GitHub repository:
https://github.com/teastainGit/ESP_NOWpeer2peer/blob/main/ESPpeer2peer/ESPpeer2peer.ino
has an example of one sketch that can be copied over to another device, change the MAC address and it works with each unit talking both ways with each other!

That's perfect Lewis, it worked!

I repeated the same steps as you described and had the same results (it works with 16MB and stops working with 4MB configuration).

So, although the root cause and definitive solution are unclear, at least we can keep using our Core2 this way.

Many thanks for sharing a solution.

Wish you all the best.

I decided me for M5 Stack, because I like the different sensors and Cores also look good. An a shop nearby sells that stuff.
Everything else is fine! I ordered another Distsensor to see what happens
I just finished my project. But everything depends on a correct distance.

I will see. Thanks so far

You may disregard this post. I changed for another USB cable and was able to recover COM3

I've never had any problems with the DS18B20 sensor powered at 5V, with an external 4.7k resistor. Never any esp32 or even Raspberry Pi burnt out.

I did a few tests:

24 m cable with 8 sensors of 1m at the end sensors powered by 3.3V

Works well with 4.7k external resistor
Also works well with internal resistor using pinMode(33, INPUT_PULLUP)
No errors (-127 or not detected) at all in all cases

I'll test soon with longer cables.

But, most important I use certified DS18B20, not bad quality copies that are good only for short distance.

Hi,

Thank you for the guidance, I now have it "working" but had to change quite a bit of code.

The Core2 download "pack" that I initially installed has completely different example code as well as the M5_AD1115 library has a few typo's in it so the examples don't compile to start.

I now know not to trust the initial download "pack" and over write the separate library's with the library's for the separate GitHub library's, then check for Typo's.

M5Stack should review every download "pack" to make sure all their examples work out the box, to avoid confusion.

Now I have working code, all I wanted was to have a simple Volt Meter that I can build into a Test Fixture and read voltage back to a C# GUI, now the code from your links only shows a negative voltage, the only way to correct this is to swap the positive and negative connection points to my circuit I am wanting to measure.

It's not ideal, but at least I have a working solution, Thank you again.

And some more here
https://github.com/m5stack/M5_Hardware/tree/master/Structure

Hang on I have a mighty headache this morning so need things dumned down.

Please explore how you have installed the software, connected hardware and tried to access the devices in M5Burner and are you sure you are accessing the correct com port?

actually just tried and it has similar issues. If you compile some of the examples with all warnings turned on in the IDE, the compiler stops

error: unused variable 'names' [-Werror=unused-variable] static constexpr const char* const names[] = { "none", "wasHold", "wasClicked", "wasPressed", "wasReleased", "wasDeciedCount" }; ^~~~~ cc1plus: some warnings being treated as errors

M5Stack supply screw kits but M3 socket head screws are cheap enough on Amazon and ebay

I found that the 1/ portTICK_RATE_MS is 1 msec, but does this time accuracy depend on the accuracy of the internal RTC?

Hello @mirandabar

for M5Core2 you'll need a different library than for M5Stack (Base, Fire, etc.).

Have a look at this thread here.

Thanks
Felix

Hello @mirandabar

have a look here. (Wake from touch in light or deep sleep.)

Thanks
Felix

Hello, I'm getting a similar error, trying to use the arduino samples for the M5 echo. Please let me know how I could resolve this. Thanks!
Documents/M5-ProductExampleCodes-master/Core/Atom/AtomEcho/Arduino/EchoSTT/EchoSTT.ino: In function 'bool InitI2SSpeakOrMic(int)':/Documents/M5-ProductExampleCodes-master/Core/Atom/AtomEcho/Arduino/EchoSTT/EchoSTT.ino:39:33: warning: 'I2S_COMM_FORMAT_I2S' is deprecated [-Wdeprecated-declarations]
.communication_format = I2S_COMM_FORMAT_I2S,
^~~~~~~~~~~~~~~~~~~
In file included from/Library/Arduino15/packages/esp32/hardware/esp32/2.0.9/tools/sdk/esp32/include/driver/include/driver/i2s.h:16,
from //Documents/M5-ProductExampleCodes-master/Core/Atom/AtomEcho/Arduino/EchoSTT/EchoSTT.ino:12:
//Library/Arduino15/packages/esp32/hardware/esp32/2.0.9/tools/sdk/esp32/include/hal/include/hal/i2s_types.h:87:5: note: declared here
I2S_COMM_FORMAT_I2S attribute((deprecated)) = 0x01, /!< I2S communication format I2S, correspond to I2S_COMM_FORMAT_STAND_I2S/
^~~~~~~~~~~~~~~~~~~
In file included from //Documents/Arduino/libraries/FastLED/src/FastLED.h:75,
from //Documents/Arduino/libraries/M5Atom/src/utility/LED_DisPlay.h:4,
from //Documents/Arduino/libraries/M5Atom/src/utility/LED_DisPlay.cpp:1:
//Documents/Arduino/libraries/FastLED/src/fastspi.h:157:23: note: #pragma message: No hardware SPI pins defined. All SPI access will default to bitbanged output

pragma message "No hardware SPI pins defined. All SPI access will default to bitbanged output" ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//Library/Arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/esp-2021r2-patch5-8.4.0/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld: /private/var/folders/0t/yz2z12qx3c921x7fdqmtll4r0000gn/T/arduino/sketches/9E06B621E90448B5520779C00ED5183B/EchoSTT.ino.elf section .dram0.bss' will not fit in region dram0_0_seg'
//Library/Arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/esp-2021r2-patch5-8.4.0/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld: DRAM segment data does not fit.
//Library/Arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/esp-2021r2-patch5-8.4.0/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld: DRAM segment data does not fit.
//Library/Arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/esp-2021r2-patch5-8.4.0/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld: region `dram0_0_seg' overflowed by 5056 bytes
collect2: error: ld returned 1 exit status

exit status 1

Compilation error: exit status 1

@ajb2k3 Sadly didn't get it to work so far... But thanks anyways :-)

Have you charged it?