Time Without delay: millis and State Machines

10 Lektionen in dieser Stufe

1. Why delay Freezes Everything Else
   Demonstrate how blocking waits make inputs and outputs unresponsive. · Lab: Blink an LED with a two-second delay and show that button presses are missed.
2. Measuring Elapsed Time with millis and unsigned long
   Read the millisecond counter and store timestamps in the correct type. · Lab: Blink an LED using a stored timestamp and interval, with a button staying responsive.
3. Rollover-Safe Interval Arithmetic
   Write interval comparisons that keep working when the counter wraps after about 49 days. · Lab: Simulate rollover with a small 8-bit counter and prove the subtraction form survives it.
4. Several Independent Timers in One Loop
   Run multiple periodic activities, each with its own timestamp. · Lab: Blink three LEDs at 300, 700 and 1100 ms while reading a potentiometer.
5. Thinking in States: Drawing a State Diagram
   Describe behaviour as states, events and transitions before coding. · Lab: Draw the state diagram of a pedestrian crossing with a request button.
6. Implementing a State Machine with enum and switch
   Translate a state diagram into an enum, a state variable and a switch. · Lab: Code the pedestrian crossing from your diagram with no delay calls.
7. Non-Blocking Debounce with Timestamps
   Debounce inputs by time comparison instead of waiting. · Lab: Replace the delay-based debounce in a counter sketch and verify zero miscounts in 100 presses.
8. Detecting Short, Long and Double Presses
   Classify button gestures using a small state machine. · Lab: Print SHORT, LONG or DOUBLE for each gesture on one button.
9. Timeouts, Retries and Fail-Safe States
   Add time limits so a program never waits forever and falls back to a safe condition. · Lab: Add an inactivity timeout that returns a menu to its idle screen and silences outputs.
10. Splitting loop into Cooperative Task Functions
    Organise a program into short task functions that each return quickly. · Lab: Restructure a sketch into readButtons, updateLogic and updateOutputs tasks and measure loop time.

Abschlussprojekt

A fully non-blocking kitchen timer with LCD, one-button short, long and double-press control, buzzer patterns and a safe timeout state.

Teile für diese Stufe

• 1 × UNO-compatible board
• 1 × USB cable matching the board
• 1 × Solderless breadboard 830 points
• 1 × Jumper wire set male-male and male-female
• 1 × LCD 16x2 with I2C backpack
• 3 × Tactile push button
• 4 × LED 5 mm assorted
• 4 × Resistor 220 ohm
• 1 × Passive buzzer
• 1 × Potentiometer 10 kilohm

In jeder Lektion legst du die passenden Teile direkt in den Warenkorb. Arduino-kompatibel →