Reverse engineering ELRO HA51 wireless: Difference between revisions
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After sniffing a few times this the result:<br> | After sniffing a few times this the result:<br> | ||
"Put alarm off" with all dips off:<br> | "Put alarm off" with all dips off:<br> | ||
[[File:Elro_HA51_433_alloff_alarmoff. | [[File:Elro_HA51_433_alloff_alarmoff.png]]<br> | ||
"Put alarm off" with all dips on:<br> | "Put alarm off" with all dips on:<br> | ||
[[File:Elro_HA51_433_allon_alarmoff. | [[File:Elro_HA51_433_allon_alarmoff.png]]<br> | ||
As you can see, the first pulse is always short, the next 8 pulses is the code of the system, dip "off" is a small pulse, a wide pulse is dip "on". | As you can see, the first pulse is always short, the next 8 pulses is the code of the system, dip "off" is a small pulse, a wide pulse is dip "on". | ||
Revision as of 19:27, 30 July 2012
What is it
It's a alarm system, used with wireless accessories. We have a central and a remote control:
Setup
We opened the device, no internal alarm trigger's where used. The system contains 2 board:
- Logic board
- 433 receiver
We hooked up a logic analyzer on the 433 receiver board to "snif" the datastreams:
We opened the remote to change the dipswitches:
After sniffing a few times this the result:
"Put alarm off" with all dips off:
"Put alarm off" with all dips on:
As you can see, the first pulse is always short, the next 8 pulses is the code of the system, dip "off" is a small pulse, a wide pulse is dip "on".