top> Sample sketch

breadboard

• LED x1: notification
• Button x1: create invoice request
• download fritzing file

Arduino Sketch

• sample.ino

variables

• LnShield instance

setUp()

• GPIO settings
• initialize LnShield
• set callback functions

loop()

• get button status
  • if pushed, call create invoice API.
• call eventPoll()
  • send and receive between Ptarmigan(ping/pong)
    • if ping/pong fail, goto ERROR status and call error callback function.
  • check internal status
    • if status change, call change status callback function.
    • Arduino can use API on STATUS_NORMAL status.
  • check local amount
    • if amount change, call change amount callback function.

callback functions

• callbackChangeStatus()
  • something LnShield status changed without ERROR status.
    • callbackError() is called when ERROR status.
• callbackChangeMsat()
  • local amount changed.
    • First status change to STATUS_NORMAL, this function will be called.
• callbackError()
  • Library caught error(maybe fail connect to Raspberry Pi).
  • Never return user application.
    • push RESET button on Arduino