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

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:

**broken link removed**

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.

The ESP8266 is cheap and can be programmed with the free Arduino IDE program and USB.
We have a section for it here. IoT - Internet of Things
I am using this: http://www.simpleiothings.com/10-diy-wifi-smoke-alarm-notifier-roost-nest-alternative-full-tutorial/
It connects to "If This Then That" http://ifttt.com/wtf
to send me an email and a phone call IF my smoke alarm sounds.
Be sure that it will work in Germany.

Another option is Home Automation Using ESP8266
https://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.

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.

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.

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.

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!

Hellmut1956 said:

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!

Click to expand...

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.

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.

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

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.

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!

Hellmut1956 said:

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

Click to expand...

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.

You need to have JAVA installed in your computer. If you don’t have, go to this website: **broken link removed**, 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?

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!

Still blocked by serious health problems. I had to be at the hospital for 10 days due to the fact that my blood sugar was way too high. I guess it will still take some weeks before I can continue.

Hellmut1956 said:

the fact that my blood sugar was way too high.

Click to expand...

Some things that might help you understand things better:
1. Hemoglobin A1c measured (hA1c) is a based on a weighted average over about 3 months. However, it in different units than blood sugar.
2. Once a red blood cell takes on too much sugar, it's useless (saturated) until replaced.
3. New red blood cell get created about every 6 weeks.
4.High blood sugar kills your body slowly
5. Low blood sugar can kill you quickly. Coma is easier.
6. Symptoms of high/low blood sugar are similar, but not identical.
7. The more lows you have says the body will have more trouble detecting lows in the future.
8. Know what excessive thirst and excessive urination is. They are symptoms of high blood sugar.
9. Dizzyess, light-headed is the low symptom I can feel the most. If lying down, I can't tell. Get up if you were sleeping.
10. Irritability is probably the high symptom I fell the most.
11. Tight control is very difficult to achieve. No experience with CGM's (Continuous Glucose monitoring)
12. Learn about the glycemic index of foods. Even if you don't, you'll figure it out. White bread, refined sugars, ice cream, pizza ffor example create a high spike, so they need to be limited and/or compensated for. How you cook a food may change the glycemic index.
13. I can cure neuropothy (tingling in feet) at it's onset. "Cure" means, it will go away for long periods up to a year or more, but tit can come back and be fixed again.
14. Keep blood pressure under control to protect your kidneys.
15. The liver dumps glucose into he blood stream if needed.
16. Triglycerides are basically a high density storage of glucose.
17. Fat is excess storage.
18. The greatest motivation to achieve good control is that it can kill the male sexual response.

Pay attention to blood viscosity. Push on your fingernail until it turns white and release. It should turn red again very quickly. As soon as you release.

Your energy levels will take up to 3 months to get close to normal after an extended high/

Thx KeepItSimpleStupid. Since about 2 months I am using the FreeStyle Libre 2 system from Abbott. It keeps a reader of a sensor placed on the upper arm. So every about 15 minutes the reader monitors my level of sugar and an alarm rings when the upper or lower limit is reached and/or past. So the reader can be connected to an app that runs on my pc to archive its reading and display diverse statistics. So when the alarm sounds, I do keep the reader in a pocket of the skirt I am wearing, it displays if either the low or the high limits have been crossed. So it demands me to scan the sensor that keeps monitoring the tissue of my arm. So I am learning what doses of short term insulin to inject depending on what my meal will consist of and what sugar level I have. So, when I am eating sugar-rich food I do increase the doses when the value gets too high also. I do carry sugar tablets with me to take if the lower limit is approached. So far the lower limit was reached much less than 0.1% of the time. Thx God, my insurance here in Germany pays those expensive sensors of which each just works for 14 days.

I thought the Libre 2 didn't have alarms? Are you saying the scanner can have an alarm that demands you to scan the sensor?

There is another CGM that uses belly sensors that will generate alarms automatically.

I have insurance that MAY cover a CGM. it won't cover the insulin pump because my C-peptide level is low, but not low enough.

My biggest problem is not injecting short-term soon enough. e.g 20 minutes before a meal.