TinyShield BLE nRF8001 20-byte limit?

[CloudCityEvan]

Does the nRF8001 BLE Shield have a 20-byte limit per transmission? I thought I saw that in the code but just wanted to verify that.

If that's the case, are there good (or just commonly-used) strategies for breaking up data to send to a Central device if we need to send more than the 20-byte limit will handle?

Thanks!

-Evan

[Ben Rose]

Correct- BLE has 20 data bytes per packet, so anything sending more data than that is using a multi-packet protocol of some sort. These can be really simple or really complex. A simple way is just having a few byte header that's a message ID, packet number, total packets. Looking at Apple's ANCS BLE protocol may be instructive(or just overwhelming), but it's well designed.