How to Use Teensy 4.0 Bottom SMT: Examples, Pinouts, and Specs

The Teensy 4.0 Bottom SMT, manufactured by PJRC, is a compact and high-performance microcontroller board designed for rapid prototyping and embedded applications. It features a powerful 600 MHz ARM Cortex-M7 processor, making it ideal for projects requiring high computational power and real-time processing. The Bottom SMT variant is specifically designed for surface-mount applications, allowing for a more compact and robust integration into custom PCBs.

• Robotics and automation systems
• Audio processing and synthesis
• High-speed data acquisition
• IoT (Internet of Things) devices
• Advanced motor control
• Machine learning and AI applications
• Custom embedded systems

• Processor: ARM Cortex-M7, 600 MHz
• Flash Memory: 2 MB
• RAM: 1 MB
• EEPROM: 4 KB (emulated)
• Operating Voltage: 3.3V
• Input Voltage Range: 3.6V to 5.5V
• Digital I/O Pins: 40 (35 PWM-capable)
• Analog Input Pins: 14 (12-bit ADC)
• Communication Interfaces: UART, SPI, I2C, CAN, USB (Host/Device)
• Clock Speed: 600 MHz (with dynamic scaling)
• Dimensions: 1.4 x 0.7 inches (35.56 x 17.78 mm)
• Temperature Range: -40°C to 85°C

The Teensy 4.0 Bottom SMT has a total of 48 pads, including power, ground, and I/O pins. Below is a summary of the pin configuration:

1. Powering the Board:

   • Provide a regulated 3.6V to 5.5V input to the VIN pin. The onboard regulator will supply 3.3V to the microcontroller.
   • Alternatively, you can power the board directly via the 3.3V pin if an external regulator is used.

2. Programming the Board:

   • Install the Arduino IDE and the Teensyduino add-on from PJRC's website.
   • Connect the Teensy 4.0 to your computer via USB.
   • Select "Teensy 4.0" as the board in the Arduino IDE and upload your code.

3. Connecting Peripherals:

   • Use the digital I/O pins for interfacing with sensors, actuators, and other devices.
   • For analog inputs, connect sensors to the A0-A13 pins.
   • Use the communication pins (UART, SPI, I2C, CAN) for advanced interfacing.

4. Surface-Mount Integration:

   • Solder the Teensy 4.0 Bottom SMT onto a custom PCB using the provided pads.
   • Ensure proper alignment and use a reflow soldering process for best results.

• Voltage Levels: All I/O pins operate at 3.3V logic levels. Do not apply 5V directly to any I/O pin.
• Heat Dissipation: For high-performance applications, ensure adequate heat dissipation to prevent overheating.
• Bootloader Mode: Use the PROGRAM pin to manually enter bootloader mode if needed.
• Static Protection: Handle the board with care to avoid damage from electrostatic discharge (ESD).

The following example demonstrates how to blink the onboard LED (D13):

// Blink the onboard LED on Teensy 4.0
const int ledPin = 13; // Onboard LED is connected to pin 13

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

void loop() {
  digitalWrite(ledPin, HIGH); // Turn the LED on
  delay(500);                 // Wait for 500 milliseconds
  digitalWrite(ledPin, LOW);  // Turn the LED off
  delay(500);                 // Wait for 500 milliseconds
}

1. Board Not Recognized by Computer:

   • Ensure the USB cable is functional and supports data transfer.
   • Check if the board is in bootloader mode by pressing the PROGRAM button.

2. Code Upload Fails:

   • Verify that "Teensy 4.0" is selected as the board in the Arduino IDE.
   • Ensure the Teensyduino add-on is installed correctly.

3. Overheating:

   • Check for excessive current draw from connected peripherals.
   • Ensure proper ventilation or add a heatsink if necessary.

4. I/O Pins Not Responding:

   • Confirm that the pins are configured correctly in your code.
   • Check for short circuits or incorrect wiring.

Q: Can I use 5V sensors with the Teensy 4.0?
A: Yes, but you must use a level shifter to convert 5V signals to 3.3V logic levels.

Q: How do I reset the Teensy 4.0?
A: You can reset the board by briefly connecting the RESET pin to GND.

Q: Is the Teensy 4.0 compatible with Arduino libraries?
A: Most Arduino libraries are compatible, but some may require modifications for the ARM Cortex-M7 architecture.

Q: Can I use the Teensy 4.0 for audio processing?
A: Absolutely! The Teensy 4.0 is well-suited for audio applications and supports the PJRC Audio Library.

This concludes the documentation for the Teensy 4.0 Bottom SMT. For further details, refer to the official PJRC website.