How to Use Adafruit Trinket 3V: Examples, Pinouts, and Specs

The Adafruit Trinket 3V is a compact and versatile microcontroller board that harnesses the capabilities of the ATtiny85 microcontroller. Designed for hobbyists and professionals alike, the Trinket 3V offers a cost-effective platform for projects where space is at a premium and power consumption is a concern. Its small size makes it ideal for wearables, portable projects, and Internet of Things (IoT) devices.

• Wearable electronics
• Small robotics projects
• USB peripheral development
• Prototyping IoT devices
• Educational purposes for learning electronics and programming

• Microcontroller: ATtiny85
• Operating Voltage: 3.3V
• Input Voltage: 3.5V to 16V (via BAT+ pin)
• Digital I/O Pins: 5 (of which 2 are used for USB if the USB interface is enabled)
• PWM Channels: 3
• Analog Input Channels: 4
• Flash Memory: 8 KB (ATtiny85) with 2.75 KB used by bootloader
• SRAM: 512 bytes
• EEPROM: 512 bytes
• Clock Speed: 8 MHz
• Dimensions: 15.5mm x 31mm x 5mm

1. Powering the Trinket: Connect a battery or power supply to the BAT+ and GND pins, ensuring the voltage is within the 3.5V to 16V range.
2. Connecting I/O: Attach sensors, actuators, or other peripherals to the GPIO pins as required by your project.
3. Programming: Use the USB connection to program the Trinket with the Arduino IDE or other compatible software.

• Always ensure that the power supply voltage does not exceed the recommended range to prevent damage.
• When using PWM outputs, ensure that the connected devices are compatible with the 3.3V logic level.
• To minimize noise and power consumption, avoid using unnecessary pull-up or pull-down resistors if possible.
• Use capacitors for power supply decoupling to reduce voltage spikes and noise.
• Remember that using the USB interface for programming will consume two digital I/O pins (#0 and #1).

• Trinket not recognized by the computer: Ensure that the USB cable is properly connected and that the Trinket's bootloader is functioning correctly.
• Incorrect voltages at I/O pins: Verify that the power supply is within the specified range and that there are no shorts or open circuits.
• Inability to upload sketches: Check the selected board and port in the Arduino IDE, and ensure that the correct driver is installed.

• If the Trinket is not recognized, try using a different USB cable or port, and double-check the soldering of the USB connector.
• For voltage issues, use a multimeter to check the power supply and the voltage at the I/O pins.
• When having trouble uploading sketches, consult the Adafruit guide for setting up the Arduino IDE with the Trinket.

// Blink an LED connected to pin #2 on the Adafruit Trinket 3V

#define LED_PIN 2

void setup() {
  // Set the LED pin as an output
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  // Turn the LED on
  digitalWrite(LED_PIN, HIGH);
  delay(1000); // Wait for 1 second
  // Turn the LED off
  digitalWrite(LED_PIN, LOW);
  delay(1000); // Wait for 1 second
}

Note: This code is for demonstration purposes and assumes that an LED with an appropriate current-limiting resistor is connected to pin #2 of the Trinket 3V.

For further assistance, refer to the Adafruit Trinket 3V forums and the extensive online resources available for troubleshooting and project ideas.