Author Topic: Recommendation Alarm Bell Mote based on smoke sensors SW Design?  (Read 1022 times)

overlord

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Hello,

I plan to rip some cheap battery based Smoke Sensors and modify them to use them as Fire Alarm and Burglar Alarm bells.
Implementing the sensor stuff is a peace of cake since I only need to detect, when smoke alarm is triggered wake up the Moteino which sends the alarm state of smoke/fire to my Gateway.
But I would like to use the smoke detector also as output node in case other sensors detect motion.
Motion Sensor ---------> sends Motion------->Gateway-------->try to reach all Alarm Bells...
I think the best way is the the node wakes up periodically lets say every 10 seconds. It sends its Batttery state and the Gateway replies with Fire the Alarm or not in the ACK phase. Or the other way arround Mote wakes up periodically and waits for burst messages from the Gateway.
Does anybody has an example for this please?
What would be the easiest solution which preserves the Battery the most. 
Best Regards,
René

 

Felix

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Re: Recommendation Alarm Bell Mote based on smoke sensors SW Design?
« Reply #1 on: October 19, 2016, 11:30:48 AM »
I think LISTEN_MODE is your best bet in this case.
This way you can sleep your mote indefinitely until either an interrupt from the smoke occurs, or the radio interrupt (from a burst) happens. Or if you need occasional wakes to transmit battery then sleep it at intervals. Overall would still be very low power.

overlord

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Re: Recommendation Alarm Bell Mote based on smoke sensors SW Design?
« Reply #2 on: October 21, 2016, 04:54:20 PM »
Thank you Felix.
I implemented a gateway which is 99% of its time receiving values of sensors without Listenmode capability. Those sensors only report something Movement, Temperature, Humidity, Smoke, Aliens...
Other sensors/actor combinations will have Listenmode.
I could successfully wake up a Moteino with ListenMode_Node sketch from my Gateway. I'm broadcasting to 255 for wake up burst.
The only drawback I saw in the mainloop of the gateway, that once I send a wakeup burst, my radio could not receive messages from sensors anymore, which are not compiled with ListenMode lib.
Thats why I need to reinitialize the radio in the gateway after the burst message.

Would it be better to send individual bursts or broadcast bursts to sleeping listening nodes?
BTW I control the gateway with Node.red see screenshot. So I can design prototype some flows before implementing them in software.
 

Felix

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Re: Recommendation Alarm Bell Mote based on smoke sensors SW Design?
« Reply #3 on: October 24, 2016, 11:49:31 AM »
You cannot receive and transmit at the same time. You could use another 3rd node that does the waking in a different band to not disturb the main network. It's up to you if you burst for a specific node or all, I would probably only wake the node I want to. However all listening nodes might lock the signal and wake to check the targetID then go back to sleep if they are not the target.
It's all a tradeoff, no free lunch :)