Memory footprint

Arduino Memory usage

Out of the box, this library has been setup to use a 'medium' amount of memory (read below how to reduce the memory footprint). Extended callbacks are not enabled by default, and can be anabled by #USE_EXT_CALLBACKS. See the callback examples.

This library is not using any dynamic memory allocation methods - all buffers have a fixed size, set in the AppleMIDI_Settings.h file, avoiding potential memory leaks and memory fragmentation (also, no usage of the String() class).

The minimum buffer size (MaxBufferSize) should be set to 64 bytes (also the default). Setting it to a higher value will make sending larger SysEx messages more efficiant (large SysEx messages are chopped in pieces, the larger the buffer, the less pieces needed), at the price of a bigger memory footprint.

MaxNumberOfParticipants is another way to cut memory - each session particpant uses approx 300 bytes. Default number of participants is 2 (each using 2 sockets). Beware: the number of sockets on the Arduino is limited. The W5100 support 4 (hance default number of participants is 2), the W5200 and W5500 based IP chips can use 8 sockets. (Base port can be set in APPLEMIDI_CREATE_DEFAULT_INSTANCE)

Reduce the memory footprint by a further wopping 500 bytes by #define NO_SESSION_NAME before #include <AppleMIDI.h>. This will leave out all the code to manage the optional session name. The RtpMIDI service client will show the name as (manually) defined in the directory.

Even further reduce the memory footprint by #define ONE_PARTICIPANT limiting the number of particpants to just 1. On an UNO the absolute minimum memory footprint is 21966 bytes (68%) and 945 global variables (46%). For a Leonardo that is 24906 bytes (86%) and 1111 bytes (43%) of global variables.