Under the Hood: AVR Registers, Timers and the Bare Chip

10 Lektionen in dieser Stufe

1. Navigating the ATmega328P Datasheet and Pin Functions
   Find register descriptions, electrical limits and alternate pin functions quickly. · Lab: Map every UNO header pin to its port bit and alternate functions in a table.
2. Port Registers: DDRx, PORTx and PINx
   Configure, write and read whole ports and single bits directly. · Lab: Rewrite Blink and a button reader using only port registers.
3. What digitalWrite Costs: Timing Direct Port Access
   Measure and explain the speed difference between core functions and register writes. · Lab: Toggle a pin both ways and compare frequencies on the logic analyzer.
4. Timer Hardware: Prescalers, Counters and Compare Units
   Describe how Timer0, Timer1 and Timer2 count and what the core already uses them for. · Lab: Calculate prescaler and compare values for 1 Hz, 1 kHz and 38 kHz.
5. Generating Precise Frequencies in CTC Mode
   Configure Timer1 to toggle an output pin at an exact frequency without software involvement. · Lab: Produce 1 kHz on pin 9 and verify within the analyzer's resolution.
6. Custom PWM Frequency and Resolution with Timer1
   Select fast or phase-correct PWM with a chosen top value. · Lab: Generate 20 kHz inaudible motor PWM and 16-bit LED dimming.
7. Input Capture for Accurate Pulse Timing
   Timestamp edges in hardware to measure period and frequency precisely. · Lab: Measure a signal from 10 Hz to 50 kHz and compare with pulse-counting results.
8. ADC Registers, Reference Selection and Free-Running Mode
   Set the prescaler, reference and trigger source and read results in an interrupt. · Lab: Sample at a fixed rate with the internal 1.1 V reference and measure the board's own supply voltage.
9. Writing Interrupt Vectors by Hand
   Enable timer, pin-change and ADC interrupts with ISR blocks and the correct mask bits. · Lab: Replace a pin-change library from level 12 with your own vector code.
10. Fuses, Bootloader and ISP Programming a Bare ATmega328P
    Read and set fuses carefully, burn a bootloader and upload through an ISP programmer. · Lab: Build a minimal chip circuit on a breadboard, set fuses for the crystal and upload Blink over ISP.

Abschlussprojekt

A breadboard-built ATmega328P signal generator and frequency counter programmed over ISP and written with register-level code only.

Teile für diese Stufe

• 1 × UNO-compatible board
• 1 × USB cable matching the board
• 2 × ATmega328P microcontroller DIP-28
• 2 × Crystal 16 MHz
• 4 × Ceramic capacitor 22 picofarad
• 6 × Ceramic capacitor 100 nanofarad
• 2 × Resistor 10 kilohm
• 1 × USBasp-compatible ISP programmer
• 2 × Solderless breadboard 830 points
• 1 × Jumper wire set male-male
• 1 × USB logic analyzer 8 channel
• 1 × Digital multimeter
• 4 × LED 5 mm assorted
• 4 × Resistor 220 ohm
• 2 × Tactile push button
• 1 × Potentiometer 10 kilohm
• 1 × LCD 16x2 with I2C backpack
• 1 × Passive buzzer

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