The Adafruit PiUART is a UART (Universal Asynchronous Receiver/Transmitter) interface board specifically designed for use with the Raspberry Pi series of single-board computers. This component simplifies the process of connecting UART-compatible devices, such as serial consoles, to the Raspberry Pi's GPIO (General Purpose Input/Output) pins. It is an essential tool for developers and hobbyists who need to establish serial communication between their Raspberry Pi and other hardware components.

• Serial console for Raspberry Pi debugging and configuration
• Interfacing with GPS modules, RFID readers, and other serial devices
• Data logging from sensors with UART output
• Robotics and embedded systems projects requiring serial communication

• Operating Voltage: 3.3V (matches Raspberry Pi logic levels)
• Baud Rate: Configurable, supports standard baud rates (e.g., 9600, 115200)
• Connectivity: Direct connection to Raspberry Pi GPIO header

1. Power Connection: Connect the VCC pin of the PiUART to a 3.3V pin on the Raspberry Pi GPIO header.
2. Ground Connection: Connect the GND pin of the PiUART to a ground pin on the Raspberry Pi GPIO header.
3. Data Connection: Connect the TX pin of the PiUART to the RX pin on the Raspberry Pi, and the RX pin of the PiUART to the TX pin on the Raspberry Pi.

• Ensure that the Raspberry Pi is powered off before connecting the PiUART to prevent any electrical damage.
• Use a logic level converter if you need to connect the PiUART to devices that operate at different logic levels (e.g., 5V).
• Always double-check connections before powering up the Raspberry Pi to avoid short circuits.
• For reliable communication, configure both the Raspberry Pi and the connected UART device to use the same baud rate.

• No Communication: Ensure that the TX and RX pins are not reversed and that the correct baud rate is set.
• Garbled Data: Check for loose connections and verify that both devices are using the same baud rate and data format.
• Power Issues: Confirm that the PiUART is receiving 3.3V power from the Raspberry Pi.

• If you encounter issues with serial communication, try using a different baud rate or checking the serial port settings on the Raspberry Pi.
• Use a multimeter to verify that the PiUART is receiving the correct voltage.
• Consult the Raspberry Pi's documentation for the correct GPIO pinout and ensure that you are using the correct pins for UART communication.

Q: Can I use the PiUART with a 5V logic device? A: No, the PiUART is designed for 3.3V logic levels. Use a logic level converter for 5V devices.

Q: How do I change the baud rate on the PiUART? A: The baud rate is set within your Raspberry Pi's software configuration. Refer to the Raspberry Pi's serial interface configuration settings to adjust the baud rate.

Q: Is the PiUART compatible with all Raspberry Pi models? A: The PiUART is compatible with any Raspberry Pi model that has a GPIO header with UART pins available.

Below is an example Python script for sending a simple message through the PiUART to a connected serial device. This script assumes you have already configured the serial port on your Raspberry Pi.

import serial
import time

ser = serial.Serial( port='/dev/serial0', # Replace with the correct serial port if necessary baudrate=9600, # Set the baud rate to match the connected device timeout=1 )

def send_message(message): ser.write(message.encode())

try: while True: send_message("Hello from Raspberry Pi!") time.sleep(2) # Wait for 2 seconds before sending the next message except KeyboardInterrupt: ser.close() # Close the serial connection when the script is stopped

Remember to configure the serial port on your Raspberry Pi and install the `pyserial` package before running the script. Use the command `pip install pyserial` to install the package if it's not already installed.