Core2 compatibility with modules/bases

  • Hello guys,

    First I would like to suggest to the M5 staff to add information about the compatibility of their modules/bases with Core and Core2 on the product description page. As a new user of M5 products I bought a bunch of modules to find them incompatible with the Core2.

    Now my questions:

    1. Can I use the M5 USB Module with Core2 and what bottom/base should I buy for this combo(So the PCB is protected and I can mount the Core2 on a machine?

    2. I see there is new M5GO Battery Bottom2. Does it come with the charging base(the one with the pogo pins and USB C) or I have to buy one from THIS LINK

    3. Since the M5 USB module is made for the "old system" would the M5GO Battery Bottom2 fit under the USB Module so I can stack the 3 pieces together?

    Also I would like to thank the M5 staff who were being very helpful to me so far.

  • Hi @innovationsmaker thank you for noting it, we are actually working on a new navigation system for the documentation page that will release soon, we've started with few products but gradually grow to over 200 products which require modification to our navigation system to find which products compatible with which Core device.

    We'll note it down and work hard to correct those issues ASAP.

    Regarding your questions, please let me confirm with the engineer and get back to you in a few minutes.

  • Hello @innovationsmaker

    A while ago I made a comparison sheet between M5Stack and M5Core2 bus which might help you.

    I don't own the M5 USB Module, but looking at the schematics I think it should work with the following changes in the source code:

    • MISO = use GPIO38 for M5Core2 (was GPIO19 for M5Stack)
    • SS = use GPIO33 for M5Core2 (was GPIO5 for M5Stack)

    The rest of the pins used by the M5 USB Module are the same.

    To fit the M5 USB Module mechanically under the M5Core2 you'll have to remove the little white board then remove the gray M5Core2 bottom (careful the battery is attached to the bottom). Then the M5 USB Module should fit.


  • @zontex Did you manage to find the answers for my questions? You said few minutes, its been 9 months :D

  • @innovationsmaker hi, sorry reply too late. core2 is compatible with all most products. In the early days, we had some batches of modules whose pins were too short to be incompatible, but we upgraded iteratively and replaced them very quickly. So, you can buy with confidence at present. When using it, you only need to confirm the serial number of the PIN in the program and the configuration of the power input mode. If there is any doubt, you can communicate with the customer service staff before purchasing. thank you for your support.

  • Trying to use the COMMU with the Core2, I find that it does not fit correctly (the base interferes mechanically at some points). That is a little strange.
    You promised to work on the documentation nine months ago. Is there a compatibility list in the meantime?
    How can I find out which modules fit to Core2? Without this, the Core2 is nearly useless for me.

  • Hello @JBecker32

    Just to clarify: before you try to stack any module to M5Core2 you'll need to remove the small board labelled 'Core2' and the gray bottom of M5Core2. (Careful the battery is attached to the bottom.)

    How can I find out which modules fit to Core2?

    As @m5stack mentioned above: 'If there is any doubt, you can communicate with the customer service staff before purchasing.'

    I don't own the COMMU module so I cannot test myself, but from the pictures the top side doesn't look that much different than any other module.

    Do you have a module that fits under M5Core2? If yes, what is the difference? Just curious.

    Just as an idea: maybe stack another module under M5Core2 first? E.g. an empty prototype module and then the COMMU module. Not ideal, I agree.


  • @felmue
    without removing the small pcb it would not be possible to stack any module, sure!
    But, the problem is not the fitting of the COMMU to the M5Core2, but to complete the stack with the base plate (the one with the battery that was removed from the M5Core2 before!). This base plate just does not fit to the COMMU. Why? There does not seem to be any good reason why it was designed like this !?!
    And, no, I have no other module that fits to the M5Core2. And I will not buy another one until I know that it will fit!

    When buying the M5Core2 (instead of the M5Stack), I thought that it would be an improved version of the M5Stack with advanced features. But I did not see any hint that it is not mechanically compatible. This is really bad for a modular solution like the 'M5Stack'.

    BR, Jörg.

    PS: it seems that the M5Go Battery Bottom 2 could be a solution

  • Hello @JBecker32

    ah, ok. Thank you for the clarification.

    It never occurred to me to 'reuse' the M5Core2 base plate to complete the stack. It probably won't fit under any of the modules as they are all quite different regarding where components have been placed. Plus most (all?) modules are lacking a connector for the battery anyways. So yes, the question remains as to why it has been designed like that. I guess only M5Stack engineers will now.

    Yes, the M5Go Battery Bottom 2 could be a solution. Please be aware though that since it contains additional hardware, it consumes additional energy. (The 10 LEDs alone eat about 1 mA each, even when they are off.)

    Maybe it's time to start the 3D printer and design you own?