AC4490 User Guide
Version 4.5
Laird Connectivity Solutions Support Center:
http://ews-support.lairdtech.com
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Table 2: Received Signal Strength
RSSI (dBm)
Hex Value
RSSI (dBm)
Hex Value
-92
C0
-72
63
-91
BC
-71
5F
-90
BB
-70
5B
-89
B9
-69
58
-88
B8
-68
54
-87
AE
-67
4F
-86
A9
-66
4B
-85
A2
-65
47
-84
92
-64
43
-83
8D
-63
3D
-82
86
-62
2A
-81
82
-60
25
-80
7D
-58
1A
-79
79
-56
16
-78
75
-54
13
-77
72
-52
11
-76
6F
-50
0E
-75
6B
-48
0D
-74
68
-46
0C
-73
66
-44
0B
Note: The receiver is saturated after -45 dBm and cannot accurately measure the RSSI above -45 dBm.
Write Digital Outputs
The OEM Host issues this command to write both digital output lines to particular states.
Note: This command should only be used when Protocol Status (0xC2) is not set to 0xE3.
Command: <0xCC> <0x23> <Digital Out>
Number of Bytes Returned: 2
Response: <0xCC> <Digital Out>
Parameter Range:
<Digital Out>= bit-0: GO0
bit-1: GO1
Write DAC
The OEM Host issues this command to write DA_Out to a particular voltage. The transceiver uses a PWM
(Pulse Width Modulator) to generate the analog voltage. The theory behind a PWM is that a binary pulse is
generated with a fixed rate (<Data 1>) and duty cycle (<Data 2>). As such, this pin toggles between High &
Low. This signal is filtered via an on-board R-C circuit and an analog voltage is generated.
Duty cycle specifies the ratio of time in one cycle that the pulse spends High proportionate to the amount of
time it spends Low. So, with a duty cycle of 50% (0x80), the pulse is High 50% of the time and Low 50% of
the time; therefore the analog voltage would be half of 3.3V or 1.65V. A broad filter has been implemented
on the transceiver and there is no advantage to using a slower update period. Generally, a faster update
period is preferred.
