This is a more advanced control program for the Particle Argon WIFI microcontroller used in this Instructables hospital bed controller. Instead of using multiple IFTTT recipes (one for up and one for down, for each joint,) this uses a single recipe, passing an entire command string to the Particle microcontroller. Then a state machine parses the sudo-natural language commands.

Digital assistant trigger move the bed command string

Hey Google, move the bed up 20 degrees.

Hey Google, move the bed legs up 10 degrees.

Hey Google, move the bed down.

Hey Google, move the bed up halfway.

Hey Google, stop the bed now.

• halfway
  • Move head by 35 degrees
  • Move feet by 17 degrees
• all the way
  • Move head by 50 degrees
  • Move feet by 25 degrees

• Parse commands
  • Use a single IFTTT recipe
  • String tokenizer
  • State machine command parser
• Time-based angle estimation
  • Calculate duration from estimated actuator speed
  • Account for actuator acceleration and deceleration time
• Measure DC current through pendant switches
  • Watch DC current to track actuator load and end-stops
  • Preload joint slop after detecting actuator end-stop
• Measure angle directly at bed joint
  • Hall effect angle sensor
  • Calibrate sensor reading map to real angle