MAILBOX
       
       A connected mailbox using a switch, nodeMCU, and 3.7V battery.
       
 (DIR) Repository
       
       - Started: May 2024
       - Status: Working-ish
       
       A switch is afixed to the side panel of a mailbox. When the mailbox
       cover is closed the switch is depressed. When the cover is lifted the
       switch is released, completing a circuit between the microcontroller's
       3.3V supply and a GPIO pin set to wakeup when high. When this interupt
       occurs the program connects to a access point, sends a TCP and/or UDP
       message, and then returns to a sleep state.
       
       
       Development
       ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
       WIP
       
       
       Bugs
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       Mailbox close event sometimes does not get received. Should run
       tcpdump and see if host is receiving packet, but too slow to process.
       
       
       Lessons learned
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