I am in favor of an external 5 "or 7" LCD screen compatible with M5 cores

@schlabbermampf You can delete the M5GO Bottom2 battery from your shopping list, it is reserved for CORE2 and you already have a battery in the M5Stack FIRE pack.

It is very difficult to visualize the compatibilities of CORE with modules or UNITS.
From CORE2 it's very frustrating to see the many incompatibilities.
The designation "2" of certain products suggests that they are compatible with CORE2 and this is absolutely not the case, this adds even more frustration and purchases that are useless ...
This added to the lack of clear and detailed documentation may scare many people away.
Please clarify the situation quickly!

Unfortunately the GOPLUS 2 is not specific to CORE2 it is also the same problem with the FACE2 which is not compatible with the CORE 2 ... It is a big marketing error of M5STACK.
For a better connection I added small pieces of schotch under the PCB at the level of the screws on the GOPLUS 2.

PaHUB does not work with CORE2, always the same message "name 'freq' isn't defined.
All these situations block any progress with M5stack products and add more and more frustration day after day.
Please, more testing before release to market.

it's not serious, the bug with the PaHub has not been corrected. I found myself with two CORE2 and useless Pahub.
Why market products that don't work?

@atu Can be made a test with the example of the MQTT unit

Here is the solution that I use for the extended I / O in output in order to control relays in 24V.

The connection is almost identical except GND and VCC.
VCC must not be connected for use> 5V.

@schlabbermampf ATOM lite is not compatible with CORE M5stack modules. It is preferable to use a CORE M5FIRE or M5GO

thank you very much for this very valuable information for a beginner like me.

Thanks Teastain
I have the expansion module for CORE 2
I am looking for advice on the mode of communication to use to transfer from CORE2 to the ATOM Display, and how to transmit around 20 digital variables?

What is the simplest and fastest communication solution (Modbus, UART, CAN,...) to communicate around 20 variables from a CORE2 to an ATOM DISPLAY? the two controllers will be in the same box at 10cm.
Should the data be sent as a list? do you have any examples in UIFLOW?

Same problem with the CORE2, do you have a solution for this error with M5burner V3 under win10

The update 1.9.7 works well, but impossible to configure the ATOM Display still the error message "Get configurations failed"

impossible to use the ATOM Display without the API Key

@lishengkkk all it takes is a small stroke of the cutter and the track is cut cleanly.
I scraped off the white paint to get to the copper. So if needed a drop of solder and everything works as it did at the start.

@lishengkkk I only use UIFLOW, no need to change the code once the connection is cut

@ajb2k3 J'attends avec impatience la version Française. super boulot, félicitations

With the M5Paper, Uiflow displays Alpha M5Paper and not 1.9.2...

https://www.thingiverse.com/search?q=M5stack&type=things&sort=relevant

Thanks @felmue

The PaHUB solution on internal I2C 21/22 does not seem to be the right solution.
I only have to use two EXTEND I/O with two different addresses, but Uiflow only recognizes address 0x27.
Do you have an example of using EXTEND I/O with the I2C master functions of Uiflow without going through the declaration of an EXTEND I/O unit.
I only need the 8 I / O input and to read their status

an example of use would be very useful