Using open collector output as controller

  • May 5, 2018 at 23:14 #25295

    Slightly niche question. I have a burglar alarm system which has a 100mA open collector output. The output switches “on” when the alarm is armed. I need something that can translate the “on” signal from the open collector into a Lightwaverf signal to switch on multiple plug socket adaptors. The plug sockets will have security cameras on them. The goal is to have the security cameras turn on when the alarm is armed. Does anyone have any ideas on how this could be done?

    May 6, 2018 at 08:17 #25296

    A few ideas depending on how your hacking skills go.

    1) Repurpose a Lightwaverf magnetic door switch. You would need to open this up and then use the armed signal simulate it being opened. It could then be paired to sockets. To simulate opening it, you would leave the magnetic part out so the switch was open but then use the non-armed state of the alarm to simulate it closed. Either the signal would need to be inverted or used to turn a relay NC contact across the door switch.

    2) Use a microcontroller e.g Pi 0 or ESP8266 to sense the alarmed state and send out Lightwaverf RF messages using a 433MHZ TX module to whatever devices you want to control. See for libraries to make this easier

    3) Use a microcontroller e.g. Pi 0W or ESP8266 to sense alarmed state and send out UDP messages over wifi to LightwaveRF Link box to tell it to transmit commands to the devices. This avoids the need to use a local TX unit.

    May 6, 2018 at 08:31 #25297

    Thanks very much for this, good food for thought. If I get any of the approaches to work, I will post here

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