Let's build an LED ring chaser using an ATtiny85! This project is great for beginners, combining electronics and programming in a fun way. We'll use three 74HC595 shift registers to control 24 LEDs, creating dynamic light patterns. I've pre-designed five patterns, but you can easily customize them. For easier assembly, I've also created a PCB (using JLCPCB), but you can certainly wire it up without one. Programming is done via an Arduino IDE (using any Arduino board, like an UNO, as a programmer). Let's get started!

Here's what you'll need:

• 1 x ATtiny85 Microcontroller

• 24 x LEDs

• 24 x 180-ohm Resistors

• 3 x 74HC595 Shift Registers

• 1 x 8-Pin IC Socket

• 1 x DC Power Barrel Jack

This code creates a program for an LED ring chaser using an ATtiny85 microcontroller, three 74HC595 shift registers, and 24 LEDs. The code defines six different LED patterns. Let's break down the process:

1. Hardware Setup:

* Connections: You'll need to connect the ATtiny85's pins (1, 2, and 3, as defined in `ShiftRegister74HC595<3> led(1, 2, 3);`) to the data, clock, and latch pins of the 74HC595 shift registers respectively. The shift registers then control the 24 LEDs, each with its own 180-ohm resistor. A detailed circuit diagram is crucial for correct wiring and should be consulted. The power supply connects to the circuit.

* Components: Ensure you have all components (ATtiny85, 24 LEDs, 24 resistors, 3 74HC595s, 8-pin IC socket, DC power barrel jack).

2. Software Setup:

* Library: You need the `ShiftRegister74HC595.h` library installed in your Arduino IDE.

* Code Upload: Upload the provided code to the ATtiny85 using the Arduino IDE. You'll need to select the correct board and port for your ATtiny85 in the IDE.

3. Code Explanation:

* `ShiftRegister74HC595<3> led(1, 2, 3);`: This line initializes the shift register object, specifying three shift registers are used. Pins 1, 2, and 3 on the ATtiny85 are used for data, clock, and latch respectively.

* `void loop()`: This function calls six different LED patterns (`pattern1` to `pattern6`).

* `pattern1()` - `pattern6()`: These functions control the LED patterns. They use `led.setAllHigh()`, `led.setAllLow()`, and `led.set(a, HIGH/LOW)` to control individual LEDs or all LEDs simultaneously. The `delay()` function controls the speed of the patterns.

4. Potential Issues and Further Steps:

* Circuit Diagram: The provided code lacks a circuit diagram. Obtaining and carefully following a circuit diagram is essential to avoid hardware errors.

* Pin Mapping: Double-check the pin mappings between the ATtiny85, shift registers, and LEDs to ensure everything is connected correctly.

* Power Supply: Verify that your power supply can provide enough current to power all the LEDs.

* Troubleshooting: If the LEDs don't work as expected, systematically check the wiring, power supply, and code. Use a multimeter to verify the voltage and current at different points in the circuit.