Topics created by MikaelK

@AWI it was not clear, but I was thinking of using a mosfet in combination with the water level sensor shown in my first post, which is in fact drawing about 1.4mA when dry, and around 15mA when put in water. Add those 1.4mA to the those taken by the step up, and it feels like the mosfet would lower that a lot when the node is sleeping (if I read the datasheet correctly, it draws between 25 and 250µA, depending on its operating temperature).

thank for the input

The siren probably has all four batteries in series, so you would probably have to modify the battery holder to connect two pairs in series. But yes, since you have the space for four batteries you might as well use that and double the battery life.

@Patrik-Söderström - I made some more tests but with the same conclusion... still lurking in the back of my head what to do but no good answer so far. I dont want to use RpI even if its a good sollution. Its way to expensive compared to my normal projects. Maybe install a real waterflow meter somewhere... not that expensive in that link AWI posted... dont know if it can handle a normal household flow though.

Thanks for the anwser. Sorry for the noise, it was some weak soldering issue on the gateway. Worked the whole night, but broke around noon today. It's now fixed and works. Mikael

Hello, Two things : first, the atmega chip was due to bad low fuse setting. secondly, I had some luck when reverting to 1.5.1 and got a value on domoticz because the problem came back quickly. I tested my setup with 2 others ds18b20 temp sensors and it worked with only one of them. I checked again the DHT22 on my other sensor node (an arduino nano) and it works. It seems to me that my board has some issue, and one of those temp sensor is tolerant to it (I believe the other one works but I should check that). I Checked the voltage with my multimeter and it is 3.3v as it should. But I'm not experimented on electronics and I could have done some basic mistake. Would someone have any idea ? Regards Mikael

The mySensors is focused on home-automation mostly. You always need at least one sensor, one gateway and a controller to process the data. In your scenario (car), maybe you could find an android app that communicates directly to arduino via USB, and fetches the temperature? That would be the straight forward approach I think.