--- id: 1076 title: WIFI+MQTT Smoke-Detector with 5yrs battery and ESP8266 date: 2018-08-27T02:15:19+00:00 author: xro layout: post guid: http://wp.realraum.at/?p=1076 permalink: /2018/08/wifimqtt-smoke-detector-with-5yrs-battery-and-esp8266/ responsive_meta_box_designation: - responsive_meta_box_facebook: - responsive_meta_box_twitter: - responsive_meta_box_googleplus: - responsive_meta_box_text_linkedin: - snap_isAutoPosted: - 1535328919 snap_MYURL: - snapEdIT: - 1 snapTW: - 's:380:"a:1:{i:0;a:12:{s:2:"do";s:1:"1";s:9:"msgFormat";s:15:"%TITLE% - %URL%";s:8:"attchImg";s:1:"1";s:9:"isAutoImg";s:1:"A";s:8:"imgToUse";s:0:"";s:9:"isAutoURL";s:1:"A";s:8:"urlToUse";s:0:"";s:4:"doTW";i:0;s:8:"isPosted";s:1:"1";s:4:"pgID";s:19:"1033870673255563265";s:7:"postURL";s:55:"https://twitter.com/realraum/status/1033870673255563265";s:5:"pDate";s:19:"2018-08-27 00:15:51";}}";' categories: - english - MakingCrafting - Projekte - realraum News --- Read about Flocx’s current project, a battery-saving WIFI+MQTT-enabling cheap smoke-detector here:

I wanted to do the same thing for my flat, but instead of using the IKEA one, I ordered two cheap 7€ SmartWares detectors from Amazon with 9V batteries that are advertised to give 5yrs battery life and otherwise identical hardware. Also instead of µPython I used Sming and C++. Just for the fun of it, I also added a voltage divider that measures the battery voltage at the time of alarm. You can find my [firmware on GitHub](https://github.com/btittelbach/sming_smokedetector). ](https://github.com/btittelbach/sming_smokedetector/blob/master/esp8266_smokedetector/esp8266_smokedetector.pdf) Todo for the future: motivate someone to do this for realraum. ;-> Since all 9V smoke-detectors ICs basically use the same pinout with an I/O-function on pin 7 that pulls LOW when no smoke is detected and HIGH on alarm, they are all equally easy to mod. The SmartWares are smaller than the IKEA ones though, so I did not even attempt to fit everything inside the case. More accessibility traded for lower WAF :) Note that there are 3V Lithium 10yrs battery life smoke detectors out there, which work a bit differently. For once, the ESP8266 does not run with 3.0V but needs true 3.3V, so at the very least you will need a cheap and tiny boost converter from AliExpress. Furthermore, they do not use a CS2105G0 based chip but a PIC which might not have an pin as CS2105G0-I/O-pin configured. A word of warning: In order to conserve the battery, the circuit disconnects the whole GND when no smoke is detected. Thus GND and 3V3 of the ESP8266 may be short-circuited through the unpowered buck-converter, depending on your component. So just to be safe, remove the Wemos from the circuit before connecting it via USB.