How to Use Teensy++ 2.0: Examples, Pinouts, and Specs

The Teensy++ 2.0 is a powerful and versatile microcontroller development board based on the AT90USB1286 chip. It features built-in USB support, a large number of input/output (I/O) pins, and is compatible with the Arduino IDE, making it an excellent choice for both beginners and advanced users. Its compact size and robust capabilities make it ideal for a variety of applications, including:

• Robotics and automation systems
• Interactive devices and wearables
• Data logging and sensor interfacing
• Custom USB devices (e.g., keyboards, MIDI controllers)
• Prototyping and educational projects

The following table outlines the key technical details of the Teensy++ 2.0:

The Teensy++ 2.0 has a total of 46 digital I/O pins, including 8 analog input pins. The following table provides a summary of the pin configuration:

1. Powering the Board:

   • The Teensy++ 2.0 can be powered via the USB port (5V) or through the VIN pin using an external power source (5V regulated).
   • Ensure the power source is stable and within the recommended voltage range.

2. Programming the Board:

   • Install the Arduino IDE and the Teensyduino add-on for Teensy compatibility.
   • Connect the Teensy++ 2.0 to your computer using a USB cable.
   • Select the appropriate board and port in the Arduino IDE.
   • Write your code and upload it to the board.

3. Connecting Peripherals:

   • Use the digital I/O pins for connecting LEDs, buttons, or other digital devices.
   • Use the analog input pins (A0-A7) for sensors that output analog signals.
   • For communication, use the UART, SPI, or I2C pins as needed.

• USB Communication: The Teensy++ 2.0 supports native USB communication, allowing it to emulate devices like keyboards, mice, or MIDI controllers. Use the appropriate USB libraries in your code.
• Pin Voltage Levels: Ensure that the voltage levels of connected peripherals are compatible with the 5V logic of the Teensy++ 2.0.
• Heat Management: Avoid overloading the board with excessive current. Use external power supplies for high-power peripherals.
• Bootloader Mode: If the board does not respond, press the reset button to enter bootloader mode for reprogramming.

The following example demonstrates how to blink an LED connected to pin 13:

// Blink an LED connected to pin 13 on the Teensy++ 2.0

void setup() {
  pinMode(13, OUTPUT); // Set pin 13 as an output
}

void loop() {
  digitalWrite(13, HIGH); // Turn the LED on
  delay(1000);            // Wait for 1 second
  digitalWrite(13, LOW);  // Turn the LED off
  delay(1000);            // Wait for 1 second
}

1. The board is not recognized by the computer:

   • Ensure the USB cable is functional and supports data transfer.
   • Press the reset button to enter bootloader mode and try reprogramming.

2. Code does not upload:

   • Verify that the correct board and port are selected in the Arduino IDE.
   • Check for syntax errors in your code.

3. Peripherals are not working as expected:

   • Double-check the wiring and connections.
   • Ensure that the voltage and current requirements of the peripherals are within the board's capabilities.

4. Board overheats:

   • Disconnect high-power peripherals and use external power supplies if necessary.
   • Verify that the board is not short-circuited.

Q: Can the Teensy++ 2.0 be used as a USB keyboard or mouse?
A: Yes, the Teensy++ 2.0 supports native USB communication and can emulate devices like keyboards, mice, and MIDI controllers using the appropriate libraries.

Q: Is the Teensy++ 2.0 compatible with the Arduino IDE?
A: Yes, with the installation of the Teensyduino add-on, the Teensy++ 2.0 is fully compatible with the Arduino IDE.

Q: What is the maximum current output of the I/O pins?
A: Each I/O pin can source or sink up to 40 mA, but it is recommended to stay below 20 mA per pin for safe operation.

Q: Can I use the Teensy++ 2.0 with 3.3V peripherals?
A: Yes, but you will need level shifters to safely interface 3.3V peripherals with the 5V logic of the Teensy++ 2.0.