Timestamp

Timestamp is a feature that enables you to track the date at which an event occurs.

For example with a button driver: each time we read the button's state, we want to timestamp this event. To do that, we have to save a time information representing our timestamp.

#include "timestamp.h"

time_luos_t button_timestamp;

Then we can save our timestamp's date when we read the state of the button:

ll_button_read(&button.state);
button_timestamp = Timestamp_now();

After retrieving the timestamp's value, you can do some calculation on it. For example, you can include a constant delay before measurement, or add a specific amount of time to manage future timestamp's date.

Then you can send a message with your button's value using Luos_SendTimestampMsg:

Luos_SendTimestampMsg(button_service, button_msg, button_timestamp);

All timestamp API functions can be found in Luos_engine/engine/core/inc/timestamp.h. You can also find examples that are using this feature. The examples using timestamp are:

• distance,
• light sensor,
• potentiometer.

Timestamp API

Description	Function	Return
Get the present timestamp	Timestamp_now(void);	time_luos_t
Check if a message is timestamped	Timestamp_IsTimestampMsg(msg_t *msg);	bool
Get a message timestamp	Timestamp_GetTimestamp(msg_t *msg);	time_luos_t