I have a firewood vending machine. It drops wood off of 4 stacked conveyors, the top conveyor being the last. Basically, all I need is to rig a sensor to a computer or phone that would text me a message on my phone when it is empty. The location of the vending machine does not have WIFI. Any possible way this could happen?
Hook the sensor or whatnot to the Arduino; hook a cellular GSM shield/module to the Arduino - program the Arduino such that when the sensor senses the machine is out of wood, it sends an SMS message to your phone (or elsewhere) via the GSM shield/module.http://arduino.cc/en/Main/ArduinoGSMShieldhttp://arduino.cc/en/Guide/ArduinoGSMShield
Note that such shields/modules don't tend to be cheap, plus you need to get one that is compatible with your carrier's in your market - and on top of all that, you need to get cell phone service (and SIM card) for the device to work. Plus, it will also only work in areas with cell-phone coverage, of course (if you need something else, you'll be looking at satellite phone modems and such - which are even more expensive).