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Need help to identify how to interconnect smoke alarms in my house

Discussion in 'General Electronics Chat' started by Hellmut1956, Nov 18, 2017.

  1. Hellmut1956

    Hellmut1956 New Member

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    Here in Baviera, Germany, by the end of this year, 2017, all houses do have the required smoke detectors installed. The house I have rented has a cellar, where my workshop and electronics lab for my hobbies is, a ground floor plus 2 more floors. Already for the use of WiFi we have 2 WiFi access points installed. One in the cellar in my workshop and one in the first upper floor. The reason being that the walls and floors are made using concrete and so they work as efficient Faraday cages making those 2 access points, we have Fritzboxes, a necessity to have WiFi service everywhere in our house.

    My idea is to connect something like a RaspBerry Pi ZERO W to every smoke detector, so they can monitor when the sensor activates its alarm. The raspi would then pass this information via WiFi or Bluetooth to the next ZERO W. Each ZERO W would require a small display attached to report which sensor has issued the alarm and activate the local alarm as well. If we family members are in our bedrooms we would not hear the alarm issued by the detector in the cellar, for example. Same is when somebody is ringing at our door bell, I do not here it in my workshop.

    Somebody wrote that a ESP32-OLED-Wemos-WiFi-Module-Bluetooth-Dual, URL-address:

    https://es.aliexpress.com/item/New-...-ESP-32-ESP-32S-ESP8266-OLED/32814573454.html

    would be a possible candidate for the sensors instead of a Raspi, as it already come with a small OLED display. I could not find out how such a board would programmable with the exception of the expensive Cadence SDK.

    First question:
    Has anybody experience with such a "mesh" kind of net as it should be pretty common in smart home installations.
    Second question:
    Can anybody tell me how to program the controller in the module? I have found no easy approach.
     
  2. ClydeCrashKop

    ClydeCrashKop Well-Known Member

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    Last edited: Nov 18, 2017
  3. ClydeCrashKop

    ClydeCrashKop Well-Known Member

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    Another option is Home Automation Using ESP8266
    http://randomnerdtutorials.com/home-automation-using-esp8266/
    Out of character for me, I bought this one for $20.00 to save time & searching.
    One of the projects lets an Android device control things on an ESP8266 on your own WiFi network. Not over the internet. That might be more practical for you.
     
  4. dave miyares

    Dave New Member

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  5. Hellmut1956

    Hellmut1956 New Member

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    Thx a lot ClydeCrashKop. Investigating the topics related to this project I have identified that I probably would be using an ESP32 based board. The reason I am coming back to this thread, besides taking your inputs is the result of recommendations I have received. I would use probably as ESP32 type of board to monitor the environment acustically and detect the special "ring" of the alarm of the smoke detector. As 2 of the smoke detectors would be placed in my workshop I need to be able to identify when the alarm of the smoke detector gets active and clearly be able to differentiate it from other possible noises it might encounter (i.e. the loud music of my son, or a flex in my mechanical workshop). This way I do not have to buy the expensive smoke detectors that support smart home communication protocols, I do not have to modify the smoke detectors. As the ESP32 is designed around wireless communication it seems to be an appropriate and inexpensive hardware.

    My problem is that I have never dealt with audio or any kind of acoustics I am now looking for advice to learn the topics related and receive a clue about how this kind of acustic detector can be realized. To my knowledge sound is a wave with a spectrum of frequencies and intensities. So I would assume I have to connect an adequate microphone to an ADC port of the microcontroller, use the sample frequency as one source of information and the "intensity" as the value that is being digitized. Now how with this inputs, sample rate = frequency detection and "level" as the digitized sample can be used to identify and differentiate the smoke detector alarm from other noise sources I assume special mathematics have to be applied. FFT's from what I have read might not be the proper technique. I do not want to reinventate how this analysis of the digitized samples is done and so recommendations for what to look would be highly appreciated!

    The link you gave me is perfect. But being a nerd in electronics I would like to understand "how" it is done mathematically and applying what concept. Also I would like to know what properties the microphone module has and what are the parameter choices that make one microphone module more adequate than another.
     
    Last edited: Dec 3, 2017
  6. Hellmut1956

    Hellmut1956 New Member

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    I am currently fighting to get my IDE for the ESP32 working. I have tried many IDE's but have failed to get my board, the ESP32 with OLED display to work.
     
  7. large_ghostman

    large_ghostman Well-Known Member Most Helpful Member

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    Not sure because we had to have a panel fire alarm because of the lab being near the house. But double check the rules for building control, I am sure i have seen a EU directive on connecting sensors, i cant remember if its business only or if the rules also covered houses.

    No idea about Germany, but check the rules for things like house of multiple occupancy, this will tell you of any restrictions regarding what, or how you can connect. It might not apply to domestic, i honestly dont remember because it got really complicated really quickly in our situation.

    I am not rules for rules sake, but i am aware that some insurance companies can be really funny paying out in a fire if your not 100% to the letter.
     
  8. dave miyares

    Dave New Member

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  9. Hellmut1956

    Hellmut1956 New Member

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    Little Ghostman: i think it is good practice not to mess in a device whose proper function effects the liability. There are such alarms with interconnection., but just to upgrade a device capable to be networked costs 71,- Euros for each alarm and i didn't even look for what the central controller would cost. I want to base my solution following a youtube video that combines an ESP32 board, you get them for approximately 2 Euros a piece and a small microphone board. The most expensive part from the hardware point of view is the case in which I place the boards and the cables to connect microphone box with ESP32 containing case. I plan to use a rechargeable battery and have the battery being monitored by the ESP board itself. But the mess is that I am not able to program the ESP board neither from the Arduino IDE, I do not have the links required, I am not able to use the Micropython approach nor a third I just can't remember its name.

    I do have a guess that the Micropython problem is due to using Python 3.6 and not 2.7. In the next days I will look into it!
     
  10. large_ghostman

    large_ghostman Well-Known Member Most Helpful Member

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    These are not units I have used, i wasnt trying to be unhelpful. I had a near miss with an insurance issue over modifying the alarm system. If your sure its ok where you are then thats cool.

    I use python 3 myself and you are correct, python 2 and 3 dont always play nice together. But it shouldnt be too hard to drop back to 2 unless you have used the libs heavily, but i am pretty sure your aware of this.
    The units themselves i will be looking into, they might be of use for a project i am currently trying to do. if i come up with anything useful i will post it for you.

    These seem to be popular units here so i will give them a look, the normal units i use for this kind of thing are expensive for what you want to do.
     
  11. large_ghostman

    large_ghostman Well-Known Member Most Helpful Member

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    I might have the cadence SDK, i will need to look. You sure these are real 'mesh' devices? I ask because if they are, i may have another way for you.
     
  12. large_ghostman

    large_ghostman Well-Known Member Most Helpful Member

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    Hold on scrap that........ Which IDE's do you have?
     
  13. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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    I'm thinking about a monitoring system too, but mainly water. This https://www.monnit.com/ system has peaked my interest. I gather you need a Win machine running all of the time, BUT you can interrogate each sensor separately via JSON data structures. There is an annunciator too.
     
  14. Hellmut1956

    Hellmut1956 New Member

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    Little Ghostman: I have not succeeded to get any of the available IDE's to work, So I am totally open as long as the IDE is for free.

    KeepItSimpleStupid: No there is no Win machine involved besides when coding!
     
  15. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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    The monit.com system seems like it does need a windows machine running all of the time. It appears that the sensors report all data to one machine which makes a lot of sense.
    It appears that an application can interrogate the sensor data on that machine and do something different than just reporting. It was just a very interesting system.
     
  16. ClydeCrashKop

    ClydeCrashKop Well-Known Member

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    You need to have JAVA installed in your computer. If you don’t have, go to this website: http://java.com/download, download and install the latest version.
    Have you been able to blink an LED?
    Are you using NodeMCU and LUA?
    Are you using Arduino and have the ESP8266 installed properly and chosen as the device?
    Have you chosen the right COM port?
    Have you put the ESP8266 in programming mode?
     
  17. Hellmut1956

    Hellmut1956 New Member

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    Sorry for being so slow to respond. I have a hard time trying to get my mind to work properly. But I was last Wednesday at the trade show "Embedded World 2018" where I met a guy from espressif who offered to help me to get an IDe for my ESP32 board running. Lets see what comes out of it!
     

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