The schematic diagram of the module is as shown below:
Experimental Procedures
Step 1: Build the circuit.
| Raspberry Pi | GPIO Extension Board | Dual-Color LED Module |
| GPIO0 | GPIO17 | R |
| GND | GND | GND |
| GPIO1 | GPIO18 | G |
#!/usr/bin/env python3
import RPi.GPIO as GPIO
import time
colors = [0xFF00, 0x00FF, 0x0FF0, 0xF00F]
pins = (11, 12) # pins is a dict
GPIO.setmode(GPIO.BOARD) # Numbers GPIOs by physical location
GPIO.setup(pins, GPIO.OUT) # Set pins' mode is output
GPIO.output(pins, GPIO.LOW) # Set pins to LOW(0V) to off led
p_R = GPIO.PWM(pins[0], 2000) # set Frequece to 2KHz
p_G = GPIO.PWM(pins[1], 2000)
p_R.start(0) # Initial duty Cycle = 0(leds off)
p_G.start(0)
def map(x, in_min, in_max, out_min, out_max):
return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min
def setColor(col): # For example : col = 0x1122
R_val = col >> 8
G_val = col & 0x00FF
R_val = map(R_val, 0, 255, 0, 100)
G_val = map(G_val, 0, 255, 0, 100)
p_R.ChangeDutyCycle(R_val) # Change duty cycle
p_G.ChangeDutyCycle(G_val)
def loop():
while True:
for col in colors:
setColor(col)
time.sleep(0.5)
def destroy():
p_R.stop()
p_G.stop()
GPIO.output(pins, GPIO.LOW) # Turn off all leds
GPIO.cleanup()
if __name__ == "__main__":
try:
loop()
except KeyboardInterrupt:
destroy()
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