@nca78 agreed. It totally depends on the application. On a 225mA button cell that may not work especially if it has to last a year or two!

@rvendrame Thanks a lot, I'm currently working on another project (electronic load). But I keep your idea in mind and will investigate when I'll continue this sensors project.

@mark-hansen I checked all links (Ebay & Ali) and they all link to the correct modules. The sensor might support 1.9-3.6V, but the modules are for 3.3 and 5.0V IO levels respectively. The blue modules have a component marked 662K at the bottom, which is a XC6206P332MR voltage regulator. The 6-pin component next to it is a level shifter so the module operates at 5V levels on the outside, and 3.3V to the SI7021. So please, explain why you think the links are wrong.

@nca78 I don't use ATAES132A. I put it in just in case I wanted to invest some more time using it. I now just use SimpleEncryption, it's secure enough for my purpose atm. (since the area I live in uses KAKU a lot, an insecure 433MHz lightswitch, I don't think anyone would be bothered to hack my temperature sensors. I found 163 433Mhz devices when I left domoticz logging for a couple of days.)

ESUN flex filament used.

@NeverDie Sorry for delay... This is example (improved version with 3d printed fixer)

BTW, I like how you both made a case for it. Very nice!

@gohan said in Arduino Pro Mini Shield for RFM69(H)W: If I remeber right that pin is used as input so the RFM69 is not receiving any 5v signal. In addition there are people claming they have the RFM69 module working on 5v on data pins and 3.3v on vcc, but I hardly suggest to do it. thank you just what i thought . about direct 5v on data...well... i seen a big red sign saying n :DONT do it! lol Level converters are so cheap...that i ordered 5 or 10 thoguether with rfm69 board. sorry about hijack this topic, i though i was on general discussion

Adafruit have a library for the htu21d which works well with Mysensors