@richardmike4

Behold - the M5Stack Tower !

Note there are some limitations on how the stacks can be used:

• I would suggest only using one battery module per stack.
• Some modules use the same GPIO - in this case only one module can be actively used at a time.
• The GPS and SIM modules use the same GPIO - the GPS continually sends data - so here it should not be used in the stack at the same time as GSM module.

"hack" one of them and move the rx/tx lines to different GPIO's then use serial1 to connect to that module.
Then you have 2 serial's and you can use both modules simultaneously.
When there is will, there is a way :D

Behold - the M5Stack Tower !

Hi Richard,

I don't think there is a hard limit on the number of "floors" or "stacks" that can be used with the M5Stack.

Behold - the M5Stack Tower below !! Using a total of 9 stacks, including Battery module , Lora module and 5x Proto modules.

Note there are some limitations on how the stacks can be used:

• I would suggest only using one battery module per stack.
• Some modules use the same GPIO - in this case only one module can be actively used at a time.
• The GPS and SIM modules use the same GPIO - the GPS continually sends data - so here it should not be used in the stack at the same time as GSM module.