8 Commands and responses
8.4.2 Display accessory
An I
2
C 4-digit 7-segment display made by Sparkfun (model COM-11441) can be connected. All commands (seen in table
8.15) to this accessory result in a response (seen in table 8.16).
Readings that are too bright for the SQM-LU will show up as
u u u u
. Readings that are too dark for the meter will
show up as
t t t t
.
Table 8.15: Display accessory command summary
Command
Description
A2Ex
Enable the display accessory.
A2Dx
Disable the display accessory.
A2Fx
Fixed mode of brightness.
A2Ax
Auto mode of brightness. Lowers brightness on dark nights.
Display at lowest brightness (30%) when greater than 19.00mpsas.
Display at medium brightness (50%) between 17.00 to 19.00mpsas.
Display at full brightness (100%) when less than 17.00mpsas.
A2M
n
x
Set the model of display (where
n
= 0-3).
A2V
n
x
Set the fixed mode brightness (where
n
= 0-7).
A2Px
Set the updating mode to periodically updating at 1Hz.
A2Rx
Set the updating modeto updating when reading request is made.
A2x
Report on the display status.
Table 8.16: Display accessory response summary
Position
Example value
Description
0
A,
Confirmation of display accessory command.
1
2,
Accessory 2 (Display).
2
e
,
E for enabled.
D for disabled.
3
m
,
Model number (where
m
= 0-3).
4
m
,
F=Fixed mode.
A=Auto mode. See table 8.15 for description.
5
n
,
Fixed brightness level (where
n
= 0-7).
6
m
P = periodically updating at 1Hz
R = updating when reading request is made.
Carriage return (0x0d), Line feed (0x0a).
An example response to “
A2x
” is:
A,2,E,0,F,2,R
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Unihedron SQM-LU Operator’s Manual -
20170728
Summary of Contents for SQM-LU
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