DocID026571 Rev 1

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AN4545

Other ranging outputs

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3.2.2

Return convergence time

Register RESULT__RANGE_RETURN_CONV_TIME {0x7c} contains the time in µs it took

for the return array on VL6180X to settle or converge on a target distance during the range

measurement.

Note:

If Return convergence time is equal to the max convergence time, then VL6180X was not

able to detect a target during the last measurement.

{0x7c} is a 32-bit register.

3.2.3

Return signal count

Register RESULT__RANGE_RETURN_VCSEL_COUNT {0x6c} contains the number of

measurement.

The following equation show the relationship between count, signal rate and convergence

time.

Note:

{0x6c} is a 32-bit register.

3.2.4

Return ambient count

Register RESULT__RANGE_RETURN_AMB_COUNT {0x74} contains the number of

The ambient counter is only active for 1/6th of the convergence time, hence the count value

must be multiplied by 6.

See the following equation of how to convert the ambient count into Mcps.

Note:

{0x74} is a 32-bit register

3.3

Reference array statistic

3.3.1

Reference signal rate

Register RESULT__RANGE_REFERENCE_RATE {0x68} contains the signal rate from the

reference array recorded during the range measurement.

To convert the reference rate into Mcps, read {0x68} and divide the value by 128.

Note:

{0x68} is a 16-bit register.

a.

The count register continues to increment till both return and reference array have converged. This means for

the Convergence time [µs], the maximum value between {0x7c} and {0x80} should be used in the equation.

Under normal operation, {0x7c} should be the larger number value.

Return Signal Rate [Mcps]

Return Signal Count

Convergence Time [µs]

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Return Ambient Rate [Mcps]

Return Ambient Count

6

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Convergence Time [µs]

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