Interrupts and Precise Timing

10 Lektionen in dieser Stufe

1. Polling versus Interrupts: Choosing the Right Tool
   Decide when an event needs an interrupt and when polling is enough. · Lab: Miss short pulses with a slow polling loop, then explain the result.
2. External Interrupts with attachInterrupt
   Attach a service routine to pin 2 or 3 on a chosen edge. · Lab: Count button edges with an interrupt while the main loop is deliberately slow.
3. volatile Variables and Short Service Routines
   Share data with a service routine correctly and keep it minimal. · Lab: Remove volatile from a working sketch, observe the failure with optimisation, then restore it.
4. Atomic Access to Shared Multi-Byte Data
   Prevent corrupted reads of values that an interrupt may change mid-read. · Lab: Provoke a torn read of a long counter and fix it by briefly disabling interrupts.
5. Pin-Change Interrupts on Any Pin with a Library
   Extend interrupt capability beyond pins 2 and 3. · Lab: Detect changes on three buttons on arbitrary pins using a pin-change library.
6. Reading a Rotary Encoder Reliably
   Decode quadrature signals into direction and steps without losing counts. · Lab: Adjust a value up and down with the encoder and show no skipped steps at speed.
7. Hardware Debouncing with an RC Filter and Schmitt Trigger
   Clean a switch signal electrically before it reaches the pin. · Lab: Add an RC network and a 74HC14 stage and compare interrupt counts before and after.
8. Counting Pulses: Frequency and RPM Measurement
   Compute rate from pulses counted in a fixed time window. · Lab: Measure the RPM of a small motor with a slot sensor or hall sensor and magnet.
9. Periodic Timer Interrupts with a Timer Library
   Run code at an exact interval independent of loop duration. · Lab: Sample an analog input exactly every 10 ms and verify the spacing.
10. Microsecond Timing with micros and Pulse Measurement
    Measure short durations and understand the 4 microsecond resolution on a 16 MHz board. · Lab: Measure the high time of a servo-style pulse you generate on another pin.

Abschlussprojekt

A bicycle-style speedometer with hall sensor pulse counting, rotary-encoder menu and trip distance on a display.

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 × Rotary encoder module with push switch
• 1 × Hall effect sensor module
• 2 × Small magnet
• 1 × Infrared slot sensor module
• 1 × Schmitt trigger inverter 74HC14
• 5 × Ceramic capacitor 100 nanofarad
• 5 × Resistor 10 kilohm
• 2 × Tactile push button
• 1 × OLED display 0.96 inch I2C 128x64
• 1 × Small DC hobby motor 3–6 V
• 2 × LED 5 mm assorted
• 2 × Resistor 220 ohm

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