I want to control brightness of 6 LEDs using RPi, Please help me i am a beginner here,
You can set up a circuit like this one (but with 6 LEDs):
Then, use this test code to set PWM value for a LED (example on pin 12, add for the rest of them):
import RPi.GPIO as GPIO # Import the GPIO library. import time # Import time library GPIO.setmode(GPIO.BOARD) # Set Pi to use pin number when referencing GPIO pins. # Can use GPIO.setmode(GPIO.BCM) instead to use # Broadcom SOC channel names. GPIO.setup(12, GPIO.OUT) # Set GPIO pin 12 to output mode. pwm = GPIO.PWM(12, 100) # Initialize PWM on pwmPin 100Hz frequency # main loop of program print("\nPress Ctl C to quit \n") # Print blank line before and after message. dc=0 # set dc variable to 0 for 0% pwm.start(dc) # Start PWM with 0% duty cycle try: while True: # Loop until Ctl C is pressed to stop. for dc in range(0, 101, 5): # Loop 0 to 100 stepping dc by 5 each loop pwm.ChangeDutyCycle(dc) time.sleep(0.05) # wait .05 seconds at current LED brightness print(dc) for dc in range(95, 0, -5): # Loop 95 to 5 stepping dc down by 5 each loop pwm.ChangeDutyCycle(dc) time.sleep(0.05) # wait .05 seconds at current LED brightness print(dc) except KeyboardInterrupt: print("Ctl C pressed - ending program") pwm.stop() # stop PWM GPIO.cleanup() # resets GPIO ports used back to input mode
The code was taken from https://www.mbtechworks.com/projects/raspberry-pi-pwm.html
Thanks mate for this.
As i am using this to make a test bench so i have to operate i on 12v supply. What should i do??
You can’t power the Pi from 12V, you can however power the LEDs from the Pi without needing another power supply I believe.