ANT Burst Mode and Custom Byte Size Transmission

[Jay]

Hi everyone,

I was not able to find a full example in the SDK or online on initializing ANT to work with burst mode. Also, I was wondering if it's possible to setup ANT with custom data byte size.

I am currently using the background scanning example in the ANT folder to send and receive data.

Thank you.

[Petter Myhre]

The changes to for example the ant_broadcast are minimal. Just use sd_ant_burst_handler_request() instead of sd_ant_broadcast_message_tx(). The channel must also be birectional to use anything other than broadcast.

[Jay]

Great, thank you. Also, in the ant_broadcast example, two channels are open: one for tx and one for background rx. Does rx require any changes to receive burst messages?

[Petter Myhre]

The RX channel must also be bidirectional.

[Jay]

Sorry, what I meant was will the current receive function in the ant_broadcast example receive all the burst messages without any modification to the original example? Also, both TX and RX channels are bidirectional in the original example (SDK 10.0). For example, if I only change from sd_ant_broadcast_message_tx() to sd_ant_burst_handler_request() in the example and send 24 bytes of data to all other ANT nodes with the same example code, will the background scanner be able to receive all 24 bytes (i.e., p_ant_message->ANT_MESSAGE_aucPayload[0] to p_ant_message->ANT_MESSAGE_aucPayload[23]) with the original RX channel configuration in the example? Thank you again.

[Petter Myhre]

I believe we are talking about two different examples, I'm talking about ant_broadcast while you are talking about ant_background_scanning. I don't think a background scanning channel can receive a burst message, it is not mentioned anywhere in the ANT Channel Search app note, and I couldn't get it to work in a quick test here. If a background scanning channel could receive a burst message having multiple nodes with background scanning channels wouldn't work very well, the burst messages are acknowledged, and are synchronized off eachother, so having multiple nodes acknowledging would be a problem. If you send 24 bytes, you should receive 3 RX events with 8 bytes in each, not 1 RX event with 24 bytes. I don't know exactly what you use case is, but maybe shared channels can be used? They can be used with burst.

[Jay]

Yes, you are right about me getting the examples mixed up. My apologies. What I am trying to accomplish is set up a mesh type network where each node will 'shout' a message and only nearby neighbours will be able to listen to that message and it does not have to be acknowledged. I was able to achieve this using the background scanning example but found that 8 bytes of message was too small. Is there any other way to achieve the same set up as background scanning example with larger message bytes than 8? Thank you.