ATtiny85 Microcontroller Documentation

Introduction

The ATtiny85 is a compact, high-performance microcontroller from Microchip Technology, designed for use in a variety of applications due to its small size and low power consumption. Based on the AVR RISC architecture, it features 8KB of in-system programmable flash memory, making it ideal for simple embedded projects, such as DIY electronics, wearables, and IoT devices.

Common Applications and Use Cases

• Hobbyist electronics projects
• Wearable devices
• Simple IoT applications
• Prototyping and educational purposes
• Battery-operated devices

Technical Specifications

Key Technical Details

• Flash Memory: 8KB
• SRAM: 512 Bytes
• EEPROM: 512 Bytes
• I/O Pins: 6
• PWM Channels: 4
• ADC Channels: 4 (10-bit resolution)
• Clock Speed: Up to 20 MHz
• Operating Voltage: 2.7V - 5.5V
• Temperature Range: -40°C to +85°C

Pin Configuration and Descriptions

Usage Instructions

How to Use the ATtiny85 in a Circuit

1. Powering the ATtiny85:

   • Connect the VCC pin to a power supply within the operating voltage range (2.7V - 5.5V).
   • Connect the GND pin to the ground of the power supply.

2. Programming the ATtiny85:

   • Use an AVR programmer or an Arduino as an ISP (In-System Programmer) to upload code to the ATtiny85.
   • Ensure the correct pin mapping is used when programming the ATtiny85 with an Arduino.

3. Connecting I/O Pins:

   • Configure the I/O pins as input or output according to your application needs.
   • Use the PWM pins for analog output applications like dimming LEDs or controlling motor speed.

4. Using ADC Channels:

   • Connect analog sensors to ADC pins for analog-to-digital conversion.
   • Ensure proper reference voltage is set in your code for accurate readings.

Important Considerations and Best Practices

• Always check the pinout and datasheet before connecting the ATtiny85 to other components.
• Avoid supplying voltage higher than the maximum rating to prevent damage.
• Use decoupling capacitors close to the VCC and GND pins to stabilize the power supply.
• Consider using an external clock source for applications requiring precise timing.

Troubleshooting and FAQs

Common Issues

• ATtiny85 not responding to programming:

  • Check connections to the programmer.
  • Ensure that the correct device is selected in the programming software.
  • Verify that the ATtiny85 has not been set to use an external clock source without one being present.

• Incorrect behavior in I/O operations:

  • Double-check the pin configuration in your code.
  • Ensure that the power supply is stable and within the specified range.

Solutions and Tips for Troubleshooting

• If the ATtiny85 is unresponsive, try using a high-voltage programming mode if available.
• For analog readings, calibrate the ADC regularly to maintain accuracy.
• Use a multimeter to verify voltage levels and continuity in your circuit.

FAQs

• Can the ATtiny85 be used with Arduino IDE?

  • Yes, with the addition of the appropriate board package, the ATtiny85 can be programmed using the Arduino IDE.

• What is the maximum current per I/O pin?

  • The maximum DC current per I/O pin is 40 mA.

• How can I reduce power consumption for battery-operated devices?

  • Utilize sleep modes and disable unused peripherals to conserve power.

Example Code for Arduino UNO as ISP

#include <avr/sleep.h>
#include <avr/power.h>

void setup() {
  // Set up code here
}

void loop() {
  // Main code here

  // Example: Entering sleep mode to save power
  set_sleep_mode(SLEEP_MODE_PWR_DOWN);
  sleep_enable();
  power_all_disable(); // Disable all peripherals
  sleep_mode();        // Enter sleep mode

  // The device will wake up here after an interrupt
  power_all_enable();  // Re-enable all peripherals
  sleep_disable();
}

Note: This example demonstrates how to put the ATtiny85 into a power-down sleep mode to conserve energy, which is useful for battery-operated devices. The actual implementation will vary based on the specific application and the required wake-up sources.