Controlling an LED via GPIO on Smart Pi One

This page describes how to control an LED using GPIO on the Smart Pi One, with detailed steps, wiring instructions, a wiring diagram, and code examples in both Python and C.

Required Materials

• Smart Pi One
• LED (with resistor around 220Ω to 1kΩ if necessary)
• Connecting wires
• Breadboard (optional for easier connections)

Wiring Diagram

Below is the wiring diagram for connecting an LED to GPIO on the Smart Pi One

Connecting the LED

Connect the LED: - Connect the longer leg of the LED (anode) to GPIO (GPIOG11/PIN: 7). - Connect the shorter leg of the LED (cathode) to ground (GND/PIN:9). - If necessary, place a resistor in series with the LED to limit the current (typically around 220Ω to 1kΩ).

Prerequisites: Configuration of smartpi-gpio

To install SmartPi-GPIO on your Smart Pi One, follow these steps:

1. Update system:

sudo apt update 
sudo apt-get install -y python3-dev python3-pip libjpeg-dev zlib1g-dev libtiff-dev
sudo mv /usr/lib/python3.11/EXTERNALLY-MANAGED /usr/lib/python3.11/EXTERNALLY-MANAGED.old

1. Clone the repository:

git clone https://github.com/ADNroboticsfr/smartpi-gpio.git
cd smartpi-gpio

1. Install the library:

sudo python3 setup.py sdist bdist_wheel
sudo pip3 install dist/smartpi_gpio-1.0.0-py3-none-any.whl

1. Activate GPIO interfaces:

sudo activate_interfaces.sh

Turning on an LED via Command Line (CLI)

Step 1: Turn on the LED

To turn on the LED on GPIO 7:

sudo gpio 7 mode out
sudo gpio 7 write 1

Step 2: Turn off the LED

To turn off the LED:

sudo gpio 7 write 0

Using Python

Creating the Python Script

1. Open a terminal on your Smart Pi One.
2. Create a new Python file using nano:

nano led_control.py

1. Copy and paste the following Python code into the file:

import time
from smartpi_gpio.gpio import GPIO

# Initialize GPIO
gpio = GPIO()

# Set GPIO7 as output for the LED
gpio.setup(7, gpio.OUT)

try:
    while True:
        # Turn on the LED
        gpio.output(7, gpio.HIGH)
        print("LED is ON")
        time.sleep(2)  # Keep it on for 2 seconds

        # Turn off the LED
        gpio.output(7, gpio.LOW)
        print("LED is OFF")
        time.sleep(2)  # Keep it off for 2 seconds
except KeyboardInterrupt:
    pass
finally:
    gpio.cleanup()  # Clean up GPIO

1. Save the file by pressing CTRL + X, then Y, and finally Enter.

Running the Python Script

To run the Python script, use the following command:

sudo python3 led_control.py