BH1750FVI

Technical Note

12/17

www.rohm.com

2009.04- Rev.B

© 2009 ROHM Co., Ltd. All rights reserved.

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H-Resolution Mode2

H-resolution mode2 is 0.5lx ( typ. ) resolution mode. It is suitable if under less than 10 lx measure ment data is necessary.

This measurement mode supports " Adjust measurement result for influence of optical window ". Please refer it. It is possible

to detect min. 0.11 lx by using H-resolution mode2.

○

Instruction set architecture for H-resolution mode2

Instruction

Opecode

Comments

Continuously H-Resolution Mode2

0001_0001

Start measurement at 0.5lx resolution.

Measurement Time is typically 120ms.

One Time H-Resolution Mode2

0010_0001

Start measurement at 0.5lx resolution.

Measurement Time is typically 120ms.

It is automatically set to Power Down mode after measurement.

○

Measurement sequence example from "Write instruction" to "Read measurement result"

ex) Continuously H-resolution mode2 ( ADDR = 'L' )

①

Send "Continuously H-resolution mode2 " instruction

ST

0100011

0

Ack

00010001

Ack

SP

②

Wait to complete 1st H-resolution mode2 measurement.( max. 180ms. )

③

Read measurement result.

ST

0100011

1

Ack

High Byte [15:8]

2

Ack

Low Byte [7:0]

2

6

2

5

2

4

2

3

2

2

2

1

2

0

2

-1

Ack

SP

How to calculate when the data High Byte is "00000000" and Low Byte is "00010010"

( 2

from Master to Slave

from Slave to Master