ESP8266 Door Contact Housing

thingiverse

Housing for low-power MQTT WiFi contact based on Arduino Mini Pro and ESP8266. It's not the prettiest thing, but it prints easily. Both processor boards, reed-contact, step-up-converter, and two AAA batteries fit snugly inside the housing. The flashing status LED of the Mini and ESP can be seen through the white PLA housing. The software/electronic part took a lot longer than expected to complete. But now it runs on some microamps in standby mode. I dropped the easy code for Arduino and instead opted for EasyESP to control the ESP. (Contact and battery status are also handled.) A circuit diagram sketch will be uploaded soon, possibly created using CAD software. Please note that a reed-contact was used for real alarm systems, so it's normally closed, not normally open. UPDATE 2 Sep 2017: A picture of the schematic has been uploaded. P.S. The lid is still loose, but it's good enough for a first print. UPDATE 3 Nov 2017: The first batteries are now empty, and my step-up-converter stopped working at 2.45V. I didn't implement persistence on openhab right away. To give you an idea of battery life, I've uploaded a diagram of the battery discharge. You can extrapolate the data yourself to estimate how long it will last for two people with normal jobs. A quick calculation suggests approximately 120 days.