ANT+ pre-event timing

[Pepam]

Hi,

I have a simple question. How should I handle situation, when need to collect data and process them before the computed data are sended via ANT+ profile which runs on 4Hz update rate? I had an idea to use repeated timer, but it is not possible, because for example when I set timer interval to 240ms to have 10ms for data processing before they are sended, the gap between data processing is getting bigger in time. Acceptable would be if the data processing would be handled 10-20ms before ANT+ data send event every time. So please, any suggestion, what should I do?

thanks,

Pepam

[Kenneth]

Typically in ant_evt_handler() you will get an EVENT_TX. Then you can start an single shot app_timer that for instance will timeout after 240ms (this might be a reasonable timeout if for instance the ANT interval is 250ms), then on the timeout handler you can run sensor sampling and write to new data to ANT using sd_ant_broadcast_message_tx().

Best regards,
Kenneth