Regarding group text messages, there is a way to get longer text messages.
In src/helpers/BaseChatMesh.h line 8, MAX_TEXT_LEN is defined to be 10 blocks of 128 bit / 16 bit ECB = 160 bytes (see also #2582). However, at least for GRP_TXT packets, this limit could actually be raised to 11 blocks = 172 bytes, as that still allows for 2 bytes MAC + 1 byte hash and not exceed the 184 bytes max. packet PDU.
Additionally: Of the current 160 bytes limit, we have four bytes for the timestamp, in the worst case 32 bytes are used for the node name, followed by a ": " separator, the text message and the zero-termination byte. Implementations now have to deal with the possibility that their longest message can be anything between 153 bytes (1 character node name) and 121 bytes (full 32 character node name), this should be documented.
Regarding group text messages, there is a way to get longer text messages.
In src/helpers/BaseChatMesh.h line 8, MAX_TEXT_LEN is defined to be 10 blocks of 128 bit / 16 bit ECB = 160 bytes (see also #2582). However, at least for GRP_TXT packets, this limit could actually be raised to 11 blocks = 172 bytes, as that still allows for 2 bytes MAC + 1 byte hash and not exceed the 184 bytes max. packet PDU.
Additionally: Of the current 160 bytes limit, we have four bytes for the timestamp, in the worst case 32 bytes are used for the node name, followed by a ": " separator, the text message and the zero-termination byte. Implementations now have to deal with the possibility that their longest message can be anything between 153 bytes (1 character node name) and 121 bytes (full 32 character node name), this should be documented.