Belle: Door bell alert with ESP8266 + IFTTT

1. Solder wire from PCB's battery wire connectors to the battery holder
2. Screw PCB and battery holder onto the acrylic sheet using M3 screws
3. Attach an acrylic sheet to the wall with 3m Mushroom Dual Lock Self Adhesive Tape

I am trying out a ghetto mounting on a wall that I cannot really drill. Masking tapes are not really for long term :p

I just mounted it up on the wall. I'm sure the mounting can be improved rather than using just masking tape.

Also, I have connect another IFTTT hook to create a spreadsheet line whenever the bell is pressed: https://docs.google.com/spreadsheets/d/1IVmJAPqfCwMcDdgMnkwIeOWHpnOo70u0uDfnYL4Y8I8/edit?usp=sharing

I'm doing an experiment to see how long an ESP8266 can last with 3 AA batteries. Would be good to learn about power consumption.