4.5 Ranging mode
Ranging mode allows the user to choose between ranging in high performance or low power consumption.
There are two modes proposed:
• Continuous: The device continuously grabs frames with a ranging frequency defined by user. The VCSEL
is enabled during all ranging, so maximum ranging distance and ambient immunity are better. This mode is
advised for fast ranging measurements or high performances.
• Autonomous: This is the default mode. The device continuously grabs frames with a ranging frequency
defined by the user. The VCSEL is enabled during a period defined by the user, using function
vl53l8cx_set_integration_time_ms(). As the VCSEL is not always enabled, the power consumption is
reduced. The benefits are more obvious with a reduced ranging frequency. This mode is advised for low
power applications.
The ranging mode can be changed using function vl53l8cx_set_ranging_mode().
4.6 Integration time
Integration time is a feature only available using Autonomous ranging mode (refer to Section 4.5 Ranging mode).
It allows the user to change the time while VCSEL is enabled. Changing integration time if Ranging mode is set to
continuous has no effect. The default integration time is set to 5 ms.
The effect of integration time is different for 4x4 and 8x8 resolutions. Resolution 4x4 is composed of one
integration time, and 8x8 resolution is composed of four integration times. The following figures represent the
VCSEL emission for both resolutions.
Figure 9. Integration time for 4x4 autonomous
Figure 10. Integration time for 8x8 autonomous
The sum of all integration times + 1 ms overhead must be lower than the measurement period. Otherwise the
ranging period is automatically increased.
UM3109
Ranging mode
UM3109 - Rev 1
page 10/20
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