How to Use Adafruit FTDI Friend: Examples, Pinouts, and Specs

The Adafruit FTDI Friend (Manufacturer Part ID: 284) is a USB-to-serial converter designed to facilitate seamless communication between a computer and microcontrollers or other serial devices. It features a built-in voltage regulator and supports multiple logic levels, making it a versatile tool for debugging, programming, and interfacing with embedded systems. The FTDI Friend is particularly useful for devices that lack native USB support, such as Arduino Pro, Pro Mini, or other microcontroller boards.

• Programming and debugging microcontrollers (e.g., Arduino Pro, Pro Mini)
• Serial communication with embedded systems
• Interfacing with TTL-level devices
• USB-to-serial bridge for custom projects
• Debugging serial data streams

The Adafruit FTDI Friend is based on the FT232RL chip and offers the following key specifications:

The FTDI Friend has a 6-pin header for serial communication. Below is the pinout:

1. Connect the FTDI Friend to Your Device:

   • Align the 6-pin header of the FTDI Friend with the corresponding pins on your microcontroller or serial device.
   • Ensure the GND pin is connected to the ground of your circuit.

2. Set the Logic Voltage Level:

   • Use the onboard jumper to select the desired logic level (3.3V or 5V). This determines the voltage level for TXD, RXD, and VCC pins.

3. Connect to Your Computer:

   • Plug the FTDI Friend into your computer using a USB Mini-B cable.
   • Install the necessary FTDI drivers if not already installed (available on the Adafruit website).

4. Open a Serial Terminal:

   • Use a serial terminal program (e.g., Arduino IDE Serial Monitor, PuTTY) to communicate with your device.
   • Select the correct COM port and baud rate.

5. Power Your Device:

   • If your device requires power, you can use the VCC pin of the FTDI Friend to supply 3.3V or 5V (depending on the jumper setting).

• Voltage Selection: Always verify the voltage requirements of your device before connecting the FTDI Friend. Incorrect voltage settings can damage your device.
• Driver Installation: Ensure the FTDI drivers are properly installed on your computer to avoid connection issues.
• Pin Alignment: Double-check the pin alignment when connecting the FTDI Friend to your device to prevent miswiring.
• Baud Rate: Match the baud rate of the FTDI Friend with the baud rate of your device for proper communication.

Below is an example of how to upload code to an Arduino Pro Mini using the FTDI Friend:

1. Connect the FTDI Friend to the Arduino Pro Mini as follows:

   • GND → GND
   • VCC → VCC
   • TXD → RXD
   • RXD → TXD
   • RTS → DTR (optional, for auto-reset during programming)

2. Open the Arduino IDE and select the correct board (e.g., "Arduino Pro or Pro Mini") and COM port.

3. Write or load your Arduino sketch and click "Upload."

4. The FTDI Friend will handle the serial communication and upload the code to the Arduino Pro Mini.

Here is an example Arduino sketch to test serial communication with the FTDI Friend:

// Simple sketch to test serial communication with FTDI Friend
void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 baud
  Serial.println("FTDI Friend Test"); // Send a test message
}

void loop() {
  if (Serial.available() > 0) {
    // Read incoming data and echo it back
    char received = Serial.read();
    Serial.print("Received: ");
    Serial.println(received);
  }
}

Upload this code to your microcontroller and open the Serial Monitor in the Arduino IDE. Type a character and press Enter to see it echoed back.

1. FTDI Friend Not Recognized by Computer:

   • Ensure the FTDI drivers are installed correctly.
   • Try a different USB cable or port.
   • Check the Device Manager (Windows) or System Information (macOS) for the COM port.

2. No Communication with Device:

   • Verify the TXD and RXD connections (TXD on FTDI Friend should connect to RXD on the device, and vice versa).
   • Ensure the baud rate matches between the FTDI Friend and the device.

3. Device Not Powering On:

   • Check the VCC pin voltage and ensure it matches the device's requirements.
   • Confirm the jumper is set to the correct voltage level (3.3V or 5V).

4. Data Corruption or Errors:

   • Use shorter cables to reduce noise.
   • Ensure proper grounding between the FTDI Friend and the device.

Q: Can I use the FTDI Friend with 1.8V logic devices?
A: No, the FTDI Friend only supports 3.3V and 5V logic levels. For 1.8V devices, use a level shifter.

Q: How do I reset my microcontroller using the FTDI Friend?
A: Connect the RTS pin on the FTDI Friend to the DTR pin on your microcontroller. This allows the FTDI Friend to trigger a reset during programming.

Q: Is the FTDI Friend compatible with Linux?
A: Yes, the FTDI Friend is compatible with Linux. Most modern Linux distributions include built-in support for FTDI devices.

Q: Can I use the FTDI Friend to power my device?
A: Yes, the FTDI Friend can supply up to 50mA of current via the VCC pin. Ensure your device's power requirements do not exceed this limit.