Convert incoming BLE-MIDI timestamp to localtime, or delayed local time. Functional with https://github.com/BLE-MIDI

timestamp_converter.c

/** Convert incoming BLE-MIDI timestamp to localtime, or delay. 
 * Timestamp out is in microseconds.*/
static uint16_t convert_timestamp(uint16_t received_ts, uint16_t conn_interval, uint16_t time_of_rx) { 
	static uint16_t prev_received_ts;
	static uint32_t prev_time_of_rx;
	static uint32_t prev_returned_ts;

	static bool 	first_timestamp = true;
	if (first_timestamp) {
		prev_time_of_rx	    	= time_of_rx;
		prev_received_ts	= received_ts;
		prev_returned_ts    	= k_ticks_to_us_near64(k_uptime_ticks()); // Time in µs

		first_timestamp 	= false;
		return prev_returned_ts;
	}

  	/** Time since last event */
	uint32_t time_span_between_evt =
			(uint32_t)(((received_ts - prev_received_ts) & 8191) 
			* 1000 
			+ ((((time_of_rx - prev_time_of_rx) 
			- (uint32_t)((received_ts - prev_received_ts) & 8191) 
			* 1000)
			+ 4096000) 
			/ 8192000) 
			* 8192);

  	/** Time until event is in sync */
	int16_t added_delay =
		(time_span_between_evt -
		 (k_ticks_to_us_near64(k_uptime_ticks()) - prev_returned_ts));
	if (added_delay < 0) {
		/** Event can't be synced back in time */
		added_delay = 0;
	}
	if (added_delay > (conn_interval)) {
		/** Event shouldn't be scheduled too far into the future */
		added_delay = (conn_interval);
	}

	/** Update stored values */
	prev_time_of_rx	 	= time_of_rx;
	prev_received_ts	= received_ts;
	prev_returned_ts 	= k_ticks_to_us_near64(k_uptime_ticks()) + added_delay;

	return (uint16_t)prev_returned_ts;
}