How to Use FTDI: Examples, Pinouts, and Specs

The FTDI (Future Technology Devices International) USB-to-Serial interface chip is a versatile component designed to convert USB signals to various serial communication protocols such as UART, SPI, and I2C. This chip is widely used in applications where a USB interface is required to communicate with microcontrollers, sensors, and other serial devices. Common use cases include:

• USB-to-serial adapters
• Microcontroller programming
• Data logging and communication with sensors
• Debugging and development tools

1. Power Supply: Connect the VCC pin to a 3.3V or 5V power supply and the GND pin to ground.
2. USB Connection: Connect the USB D+ and USB D- pins to the corresponding USB data lines.
3. Serial Communication: Connect the TXD and RXD pins to the corresponding UART pins on your microcontroller or serial device.
4. Flow Control (Optional): If using hardware flow control, connect the RTS# and CTS# pins.
5. Configurable Pins: Use the CBUS pins for additional I/O functions as needed.
6. LED Indicators: Connect the TXLED# and RXLED# pins to LEDs for visual indication of data transmission and reception.

• Voltage Levels: Ensure that the voltage levels of the FTDI chip match those of the connected devices.
• Decoupling Capacitors: Place decoupling capacitors close to the VCC pin to filter out noise.
• USB Compliance: Follow USB design guidelines to ensure reliable communication.
• Driver Installation: Install the appropriate FTDI drivers on your computer to enable USB-to-serial communication.

#include <SoftwareSerial.h>

// RX and TX pins for FTDI
const int RX_PIN = 10;
const int TX_PIN = 11;

// Create a SoftwareSerial object
SoftwareSerial mySerial(RX_PIN, TX_PIN);

void setup() {
  // Start the hardware serial communication
  Serial.begin(9600);
  // Start the software serial communication
  mySerial.begin(9600);
}

void loop() {
  if (mySerial.available()) {
    // Read data from FTDI and send it to the Serial Monitor
    Serial.write(mySerial.read());
  }
  if (Serial.available()) {
    // Read data from Serial Monitor and send it to FTDI
    mySerial.write(Serial.read());
  }
}

1. No Communication: Ensure that the correct drivers are installed and the FTDI chip is properly connected.
2. Incorrect Data: Verify that the baud rate and other serial settings match between the FTDI chip and the connected device.
3. Device Not Recognized: Check the USB connection and ensure that the FTDI chip is powered correctly.

• Driver Issues: Reinstall the FTDI drivers from the official website.
• Connection Problems: Double-check all connections and ensure that there are no loose wires.
• Power Supply: Ensure that the FTDI chip is receiving the correct voltage and that decoupling capacitors are in place.

By following this documentation, users can effectively integrate the FTDI USB-to-Serial interface chip into their projects, ensuring reliable and efficient communication between USB and serial devices.