I share today an experimental project for my mailbox. The idea was to get a pushover notification when mail delivery is done. I live in an apartment and hate to do a stupid walk to check downstairs my mailbox. Initial tests have been done with a weighter sensor on the bottom of the mailbox. But unfortunately it was too dependent on the position of the letters. During evaluation of the apds 9960 proximity sensor I got this simple idea to mesure the proximity from the bottom to the top of the mailbox, and when a letter is put inside the mailbox, the sensor detecte a change on the distance and send a notification. I don't have yet enough experience on the battery duration.

@cadet please find here the case: https://www.tinkercad.com/users/d3dPgqW3Cif-richard-borer

@gohan , the board is a great contribution from here: https://oshpark.com/shared_projects/uXIff7XO

@FotoFieber , I've built the same sensor, and it works since now 6 months with 2 AA

Few pics of my very simple DTH22 sensor long range (used to monitoring my wine cave temperature). A simple case 3D printed...

@ikkeT, I've used the PIN 3 with a door sensor, it work perfectly, just enable the mode INPUT_PULLUP on the setup.

void setup() {
pinMode(DOOR_PIN, INPUT_PULLUP);

Hi @qqlapraline , I experience the same issue. I've already built door sensors + Temp + humidity with a pro mini 3.3v and it working since 7 months with the same 2AA's.
I've done the same with the sensebender micro and in 2 weeks the battery are ko. I send temp/hum every 5 min, use sleep and interrupt for the door sensor.

Why not broadcast ? :)

@Cory , do you have a pic of the final result ?