Mohammadreza Akbari
Then use /dev/serial0 in any code which accesses the Serial Port. The BCM2837 on the Raspberry Pi3, Pi3B+, PiZeroW has 2 UARTs (as did its predecessors), however to support the Bluetooth functionality the fully featured PL011 UART was moved from the header pins to the Bluetooth chip and the mini UART made available on header pins 8 & 10. Dec 07, 2017 Wiring your RS232 to TTL adapter to your Raspberry Pi is a simple process, with it requiring only 4 of the GPIO connecting to be wired to the serial connector, even better all 4 GPIO pins needed are in a row, so it is easy to follow. Make use of our table and guide below to connect your serial connector to your Raspberry Pi. VCC connects to Pin 4.
Hardware interfaces for the Raspberry Pi 2 and Raspberry Pi 3 are exposed through the 40-pin header J8 on the board. Functionality includes: 24x - GPIO pins. 1x - Serial UARTs (RPi3 only includes mini UART) 2x - SPI bus. 1x - I2C bus. 2x - 5V power pins. 2x - 3.3V power pins. Jun 26, 2019 The Raspberry Pi has 40 GPIO pins that connect to sensors, lights, motors and other devices. Here's a map and detailed explanation of what each does, including on the Pi 4. The Raspberry Pi serial port consists of two signals (a 'transmit' signal, TxD and a 'receive' signal RxD) made available on the GPIO header. To connect to another serial device, you connect the 'transmit' of one to the 'receive' of the other, and vice versa. You will also need to connect the Ground pins of the two devices together. Follow the steps below to start the Raspberry Pi UART communication: Step 1: Connect the serial to USB converter to the Raspberry Pi board as is shown in the circuit. Then plug the Raspberry Pi supply and connect the converter to your PC. Step 2: Go to the Device Manager and find the port number that is connected to the converter.
In this tutorial, you’ll learn about Raspberry Pi serial communication (UART), and how to connect your Raspberry Pi board to the Arduino boards or PC using serial communication.
- Serial communication between Raspberry Pi and PC
- Serial communication between Raspberry Pi and Arduino
Serial communication (UART) is one of the most popular communication protocols. Most processors support this two-wire connection. Also, many of modules and sensors use serial communication to connect to the other devices.
Serial communication requires only two wires; one for transmitting data and the other one for receiving it.
The rate of the data transfer in this protocol is called the Baud rate. The unit of baud rate is bit per second.
Raspberry Pi boards have two types of UART communications. One is called PL011 and the other is called miniUART. The Raspberry Pi boards that have Bluetooth/Wireless module, use the PL011 for UART communication by default.
Warning
The voltage level of all Raspberry Pi pins, including the RX and TX pins, is 3.3 volts. So to connect a device with 5 volts voltage level to the Raspberry Pi, you should use a voltage level converter or resistance-split circuit.
You can check the Raspberry Pi website for more information about the Raspberry Pi serial communication
| Raspberry Pi 3 B or B+ | × | 1 |
| Arduino UNO R3 | × | 1 |
| TTL to USB converter | × | 1 |
| Male to Female jumper wire | × | 1 |
| Bread board | × | 1 |
| 1K Ohm Resistor | × | 3 |
To establish a serial communication between the Raspberry Pi board and your PC you need a serial to USB converter.
Follow the steps below to start the Raspberry Pi UART communication:
Raspberry Pi Serial Gpio Pins
Step 1: Connect the serial to USB converter to the Raspberry Pi board as is shown in the circuit. Then plug the Raspberry Pi supply and connect the converter to your PC.
Step 2: Go to the Device Manager and find the port number that is connected to the converter.
Step 3: Open your terminal software and set up the configuration.
Step 4: Enable UART in the Raspberry Pi.
Open the Raspberry Pi terminal and insert the following commands.
1. Open the config.txt file in the nano editor using the following command.
Add the following lines to the end of the file.
2 | enable_uart=1 |
Then press Ctrl+x and press Y to save the file and close it.
2. Reboot your Raspberry Pi.
3. Check the terminal software on your computer
4. Disconnect the serial communication between the Raspberry Pi and the Bluetooth module.
Raspberry Pi 3 Serial Pinout
5. Open cmdline.txt in nano editor.
Delete the “console=serial0,115200” line and save the file.
6. sudo nano /boot/cmdline.txtReboot your Raspberry Pi again.
7. Install the minicom terminal on your Raspberry Pi.
The following command opens the minicom terminal, set the baud rate to 115,200, and starts the serial communication.
After executing this command, you should see the following window.
Now you can test the serial communication between the Raspberry Pi and your pc.
Note
If you want to see the commands you write in the minicom terminal, you need to enable the Echo mode by pressing Ctrl+A and then entering E in the minicom terminal.
Raspberry Pi Serial Port Pins
To exit minicom, first press Ctrl+A and then enter X.
Serial Communication Between Raspberry Pi and Arduino
You can connect your Arduino boards to the Raspberry Pi using a USB cable. By doing this, you provide the Arduino supply voltage, and you can also transfer your information between Arduino and the Raspberry Pi through the serial interface
Using the following command you can open the minicom terminal at 9600 bit/sec baud rate.
Now upload your code on the Raspberry Pi board and you can transfer the information between the Raspberry Pi and Arduino.
The following code sends any text you write in the minicom terminal from the Raspberry Pi to the Arduino. Then the Arduino returns the same text to the Raspberry Pi.