Here, it is shown how to blink an LED connected to an Arduino board using PyFirmata. PyFirmata is a Python library that allows you to communicate with Arduino boards and control their GPIO pins using the Firmata protocol. By the end of this tutorial, you will have a basic understanding of how to use PyFirmata to control hardware components with an Arduino.
Prerequisites
To follow along with this tutorial, you will need the following:
- An Arduino board (e.g., Arduino Uno)
- A computer with Python and the PyFirmata library installed
- A USB cable to connect the Arduino to your computer
- An LED and a resistor (220-470 ohms) for the circuit
- Step 1: Setting up the Hardware:
First, let's set up the hardware components. Connect one leg of the LED to one end of the resistor. Connect the other leg of the LED (the longer leg, known as the anode) to the Arduino's digital pin 9. Connect the other end of the resistor to the Arduino's ground (GND) pin.
- Step 2: Installing PyFirmata:
Before we can start coding, we need to install the PyFirmata library. You can use any of python capable IDE(Integrated Development Environment). Here we will use using Visual Studio Code(VSCode). Open the terminal or command prompt and enter the following command:
pip install pyfirmataThis command will install the PyFirmata library on your computer.
- Step 3: Uploading StandardFirmata to the Arduino:
To establish communication between the Arduino and PyFirmata, we need to upload the StandardFirmata sketch to the Arduino board. Open the Arduino IDE, go to File -> Examples -> Firmata -> StandardFirmata, and upload the sketch to the Arduino.
- Step 4: Writing the Python Code:
Now, let's write the Python code to blink the LED. Open your preferred Python editor or IDE and create a new Python file. Here the python file is called LEDBlink.py.
First, we need to import the necessary modules and set up the connection with the Arduino:
import time
from pyfirmata import Arduino
# Define the port where Arduino is connected
port = 'COM3' # Replace with your port
# Establish a connection with the Arduino
board = Arduino(port)Next, we can write the code to blink the LED. We will toggle the state of the digital pin 9 (connected to the LED) with a delay of 1 second between each state change:
# Set up the pin modes
led_pin = board.get_pin('d:13:o')
# Blink the LED
while True:
led_pin.write(1) # Turn the LED on
time.sleep(1) # Delay for 1 second
led_pin.write(0) # Turn the LED off
time.sleep(1) # Delay for 1 second
Note that if you installed pyfirmata and get error not finding
pyfirmata, you may need to set the correct path by opening the command
palette in Visual Studio Code using the shortcut Ctrl+Shift+P. Next, type in settings.json and select it from the search results. This will open the settings.json file where you can add the following code snippet:
{
"python.defaultInterpreterPath": "C:/Users/Dell/AppData/Local/Programs/Python/Python311/python.exe"
}
Make sure to replace the path in the code snippet with the correct
path where your Python interpreter is installed. After adding this code
to the settings.json file and saving it, Pylance should be able to detect your Python installation correctly.
Step 5: Running the Code:
Save the Python file with a descriptive name, such as LEDBlink.py. Open your terminal or command prompt, navigate to the directory where the file is saved, and run the following command:
python LEDBlink.pyIf everything is set up correctly, you should see the LED connected to the Arduino board blinking on and off at a 1-second interval.
The complete LED blink code using pyfirmata library is below..
Conclusion: Congratulations! You have successfully learned how to blink an LED using an Arduino board and PyFirmata. This basic example demonstrates the power of PyFirmata in controlling
References
[1] Arduino LED blinking using Matlab
[2] Arduino Nano LED blink Code
