Time_stamping_value?

[MMG]

Hi Nordic Devzone,

First i want to make sure that if the clock being used by softdevice is the LFCLK (32kHz) and its counter register is 24bits ? and which prescaler is being used? because I want to send the local time (clock value ) from one device to another using Bluetooth mesh connectivity, but when i'm reading the time of the receive message from the ( const access_message_rx_t * p_message) the value of timestamp is greater than 24 bits value actually its a 32bit value , so if the counter register in the LFCLK is 24 bits how would it be possible to count up to 32 bits value ? does it mean that the clock begin used for time stamping the receive messages is different than the clock used by softdevice ? And what is the best way to keep track of time while using the softdevice ?

Thank you in advance

[Hung Bui]

Hi MMG,

The timestamp you see in access_message_rx_t is the timestamp when the packet is received. It's a local timestamp counting from the start of current timeslot. Have a look at radio_handle_end_event() in scanner.c

And note that we use TIMER0 to count time, and it's 32bit. Not the 24bit RTC.

Currently we have no use of the timestamp in the receive package yet.

[MMG]

Hi Hung, Thanks for the link to study! And once again, thanks for your explanation!

I see, so then there is no use of softdevice when using Bluetooth Mesh? If that's true, then if we take a time sample(our local time ) using TIMER0 (calling time_now()) and send this value plus the calculated drift in our TX packet, it should be enough for my use case? Since in such case, I assume the timeslot (on TIMER0) will be running all the time in our communication and we can take our time sample using TIMER0? or will the softdevice still be used which means we cannot rely only on TIMER0? Are you aware of any ongoing implementation that adds a timestamp from the sending node?