I am working on my first Arduino project. It's a Reverse Geocache. Basically, it's a puzzle where a battery-powered Arduino is mounted inside a locked box, and is able to unlock the box if the user brings the box to the correct GPS coordinates and presses a push-button (that activates the Arduino, that runs a sketch, that checks the GPS, and operates a servo to release the lock).
It's all working, but I am trying to build in a backdoor, so I can unlock the box when I need to.
I have made the Arduino USB port accessible, and my hope is that I could connect a PC, and execute the appropriate command to operate the servo to unlock the box. The command is:
The sketch that drives the whole puzzle depends on these libraries, but I am guessing the only one needed to operate the servo is PWMServo.h:
#include <PWMServo.h> #include <SoftwareSerial.h> #include <TinyGPS.h> #include <EEPROM.h> #include <LiquidCrystal.h>
I would like to be able to operate the servo without altering/replacing the uploaded sketch.
Is it possible to execute code "command prompt" style? Or can I somehow detect from within the sketch code that there is a USB connection, and have that trigger the unlock?
Finally (not the main question, but I would appreciate clarification), I have been told that the power to the Arduino should be disconnected before uploading new sketches (not sure why or if this is true). If forcing an unlock via the backdoor required uploading a new sketch, I seem to have a problem... For the puzzle to work within the locked box, the battery must be permanently connected, and also connecting to a PC via the USB seems to immediately power up the Arduino too. Does this mean uploading a new sketch would be impossible?