Linx Technologies HUM-xxx-DT - Manual (Page 17)

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As another example take the value 0x23. The high nibble is 2, so 2
channels are used. The low nibble is 3, which is a binary 0b0011, so
channels 0 and 1 are used.
Parameter 9 controls the transmitter output power level. Figure 26 shows
the power level codes and the approximate output power. The actual
output power may differ slightly from part-to-part.
Parameters 10 through 13 set the ID of the network that the module is to
join. Other modules respond only if they have this same network ID.
Baud Rate Codes
Serial Baud Rate (kbps) Baud Rate Code
1.2 0
2.4 1
4.8 2
9.6 3
14.4 4
19.2 5
28.8 6
38.4 7
57.6 8
115.2 9
reserved N/A
Figure 25: Baud Rate Codes
Transmitter Output Power Codes
Power Level Code
HUM-900-DT
TX Output Power (dBm)
00 –30
01 –20
02 –15
03 –10
04 –5
05 0
06 5
07 7
08 10
Figure 26: Transmitter Output Power Codes
Parameter 14 configures the GPIO lines to be either analog or digital.
The byte is a bit map with each bit corresponding to a single line; bit 0
corresponds to GPIO_0 and bit 7 corresponds to GPIO_7. Setting a bit to
0 makes that GPIO line digital and setting it to 1 makes the line analog.
Parameter 15 configures the GPIO lines to be either inputs or outputs.
The byte is a bit map with each bit corresponding to a single line; bit 0
corresponds to GPIO_0 and bit 7 corresponds to GPIO_7. Setting a bit
to 0 makes that GPIO line an input and setting it to 1 makes the line an
output. Note that analog lines can only be inputs.
Parameter 19 configures the GPIO lines to have either pull-up resistors to
V
CC
or pull-down resistors to ground. If this byte is set to 0 then all of the
GPIO lines have pull-up resistors. Any non-zero value configures the GPIO
lines to have pull-down resistors. Note that the tri-state configurations in
Parameter 20 take precedence over the resistors. If a line is configured to
be tri-state then the resistors are not used.
Parameter 20 configures the GPIO digital input lines to either use the
pull-up and pull-down resistors or to be tri-state. The byte is a bit map with
each bit corresponding to a single line; bit 0 corresponds to GPIO_0 and
bit 7 corresponds to GPIO_7. Setting a bit to 0 makes that GPIO line use
the pull-up / pull-down resistors as configured by Parameter 19. Setting it
to 1 makes the line tri-state, which is essentially having no resistors.
Setting an input to tri-state deactivates the resistors. This reduces the
overall current consumption by removing the current draw through the
20k
Ω pulling resistors. However, input lines set as tri-state must be in a
determined state (high or low). They cannot be left floating or unpredictable
operation may occur.
Parameters 21 through 36 contain the 128-bit key for the AES encryption
algorithm. This key must be the same as all other modules on the network.
Parameter 55 indicates if the read command was successful (00) or if there
was an error (01).