One buttom Dimmer Mbed code
Finite state machine code sample for a dimmer controller by one buttom only.
The controlled light is the green LED LD7, connected to port PA9.
Made for ST STM32F4 Discovery board using ARM Mbed library and PlatformIO IoT Ecosystem.
Challenge for students of the discipline Microprocessed Systems II at SENAI CIMATEC university center.
Keywords: One buttom Dimmer, Finite State Machine, C/C++, Mbed, STM32F4
Finite State Machine policy
States:
- DOWN select: Orange LED ON
- UP select: Blue LED ON
- FALL intensity: Decrease intensity 5% per second while the orange LED is ON and flashing off 0.2s per second
- MIN. reached: 0% intensity reached. Orange LED flashes at 5Hz until the button releases
- RISE intensity: Increase intensity 5% per second while the blue LED is ON and flashing off 0.2s per second
- MAX. reached: 100% intensity reached. Blue LED flashes at 5Hz until the button releases
Transitions:
- Initial state: UP
- Transition - UP --> DOWN: tBt<1s
- Transition - DOWN --> UP: tBt<1s
- Transition - DOWN --> FALL: tBt>=1s && i>0.0
- Transition - UP --> RISE: tBt>=1s && i<1.0
- Transition - FALL --> MIN: Bt==1 && i==0.0
- Transition - RISE --> MAX: Bt==1 && i==1.0
- Transition - MAX --> DOWN: Bt==0 && i==1.0
- Transition - MIN --> UP: Bt==0 && i==0.0
- Transition - RISE --> UP: Button release && i<1.0
- Transition - FALL --> DOWN: Button release && i>0.0
- Transition - RISE --> RISE: Bt = 1 && i < 1.0 while i = i - 0.05 every second
- Transition - FALL --> FALL: Bt = 1 && i > 0.0 while i = i + 0.05 every second
Acronyms:
- Bt = Buttom
- tBt = time Button pressed
- i = intensity
Diagram:
