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Rev 0.4
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5.2.4.1. Key Fob Compatibility with the Si4x55 RF Receiver
This section is intended to describe the compatibility between the Si4x55 RF IC working as a receiver and different
key fobs working as transmitters. Silicon Labs provides two types of demo kits containing key fobs with different
packet structures.
1. Demo kits with the key fob packet type #1 (obsolete).
These kits contain a key fob transmitter with Si4010 that is preprogrammed with the "rke_demo" example
code. These keyfobs transmit packet type #1
a. Si4010 Key Fob Demo Kit with AES Capability XXXMHz (P/N: 4010-DAAKF_XXX)
b. Si4010 Simplified Key Fob Demo Kit XXXMHz (P/N: 4010-DASKF_XXX)
2. Demo and Development kits with the key fob packet type #2:
These kits contain a key fob transmitter with Si4010 that is preprogrammed with the "rke_demo_2"
example code. These keyfobs transmit packet type #2
a. Si4010 Remote Keyless Entry Demo Kit with AES Encryption (P/N: 4010-AESK1W-XXX)
b. EZRadio Remote Control Demo Kit XXXMHz (P/N: EZR-LEDK1W-XXX)
Packet type #1 (obsolete)
The structure of the packet:
The structure of the Function Control Byte:
OUT0–OUT3 represent the four LED outputs of the receiver. Output functions are controlled by the F0–F1 function
bits.
Function bits operations:
Table 7. Keyfob Used Frequencies
Project Name
Modulation Type
Center Frequency
[MHz]
Deviation
[kHz]
“rke_demo”
FSK
433.39
60
FSK
868.96
50
“rke_demo_2”
FSK
316.66
43
FSK
433.92
59
FSK
868.30
119
FSK
917.00
120
Preamble
Sync Word
Function Control Byte
One’s complement of
Function Byte
Function Control Byte
4 byte
2 byte
1 byte
1 byte
1 byte
OUT3
F1
OUT3
F0
OUT2
F1
OUT2
F0
OUT1
F1
OUT1
F0
OUT0
F1
OUT0
F0
Summary of Contents for Si4455 Series
Page 8: ...AN692 8 Rev 0 4 Figure 6 Device Configuration Options ...
Page 22: ...AN692 22 Rev 0 4 Figure 21 Supply Current versus Time Diagram from Shutdown to RX State ...
Page 23: ...AN692 Rev 0 4 23 4 4 Radio Chip Waking Up Figure 22 Radio Wake Up Process ...
Page 35: ...AN692 Rev 0 4 35 Figure 32 Transmission Flowchart ...
Page 39: ...AN692 Rev 0 4 39 Figure 33 Reception Flowchart ...
Page 41: ...AN692 Rev 0 4 41 Figure 34 Bidirectional Variable Packet Example Project Flowchart ...
Page 47: ...AN692 Rev 0 4 47 Figure 41 Long Packet Transmission Flowchart ...
Page 48: ...AN692 48 Rev 0 4 Figure 42 Long Packet RX Flowchart ...