topic BLE Mesh message size limit in Wireless MCU

BLE Mesh message size limit

pbartlett — Thu, 22 Dec 2016 23:06:39 GMT

What is the size limit for a custom data message sent over BLE Mesh?

Re: BLE Mesh message size limit

antonioconcio — Thu, 22 Dec 2016 23:22:14 GMT

Hi Philip,

The maximum payload data in a packet is 13 bytes.

Cheers,
Antonio

Re: BLE Mesh message size limit

pbartlett — Thu, 22 Dec 2016 23:43:53 GMT

Hi Antonio,

The following definition in mesh_types.h appears to set the max length to 14.

#define gMeshMaxAppCustomDataSize_c 14

I tried changing this value but it appears to be set to 14 in the mesh binary. Mesh_SendCustomData() will return an error if meshCustomData_t.dataLength >= 14 regardless of the gMeshMaxAppCustomDataSize_c value.

Is there any way to increase the max size or is this it?

Philip

Re: BLE Mesh message size limit

antonioconcio — Fri, 23 Dec 2016 08:16:33 GMT

Hi Philip,

That is the maximum size, please remember BLE Mesh works on Advertising packets.

Yes, data size is 14B but usually 1B will be the opcode, so at the end you have 13B left as real application data.

Cheers,

Antonio

Re: BLE Mesh message size limit

pbartlett — Fri, 23 Dec 2016 17:31:15 GMT

Hi Antonio,

Thanks for the help. Does the use of advertising packets also affect the reliability of the packet delivery? ie is there a guarantee of delivery or is it maore a fire and forget with the possibility of the packet being stepped on? Please see my question regarding packet loss with BLE Mesh from a couple of days ago. https://community.nxp.com/thread/441389

Thanks

Philip

Re: BLE Mesh message size limit

antonioconcio — Wed, 28 Dec 2016 11:07:25 GMT

Hi Phil,

Yes it does somehow, for full info/details please refer to that post (I have just answered).

I hope it helps getting everything clarified,

Antonio

Re: BLE Mesh message size limit

evgenyerlihman — Thu, 16 Feb 2017 14:54:29 GMT

Hi Antonio,

As far as i understand the packet capacity for Bluetooth 4.2 grew to 250 bytes, is that a different type of packet from what is being used for NXP BLE mesh?

Thanks,

Evgeny