RGB LEDs and Ada PCA9685 servo driver breakout issuse
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RGB LEDs and Ada PCA9685 servo driver breakout issuse

by cannon fodder on Sat Nov 17, 2012 8:33 pm

Hi,

I need some help with a Adafruit 16-Channel 12-bit PWM/Servo Driver - I2C interface - PCA9685, I am using it to drive some RGB LEDs with a common anode. The issue, I have is when I turn off any of the 3 PWM pins or all of them at the same time, I have about 2-3 volts bleeding through and the LEDs remains dimly lit. My setup is a Raspberry Pi, coppler board and the Adafruit 16-Channel 12-bit PWM/Servo Driver - I2C interface - PCA9685. The LEDs have been placed on prototype broad with its current limiting resistors, and headers so it can plug into breadboard. I am using a wall wart to provide 5v dc to supply the LEDs, the RasPi has its own wall wart. The code below should turn off/on channel 0 very 2 seconds

Code: Select all | TOGGLE FULL SIZE
 from Adafruit_PWM_Servo_Driver import PWM
import time

pwm = PWM(0x40, debug=True)
pwm.setPWMFreq(50)
while True:

pwm.setPWM(0,0,4094)
time.sleep(2)
pwm.setPWM(0,4094,0)
time.sleep(2)

cannon fodder
 
Posts: 3
Joined: Fri Nov 16, 2012 6:13 pm

Re: RGB LEDs and Ada PCA9685 servo driver breakout issuse

by cannon fodder on Sat Nov 17, 2012 9:45 pm

Hi,

OK, I stripped out the common anode RGB LED, and used single LEDs instead, and it works! I will have to try a common cathode RGB LED, I will report back with my findings.

cannon fodder
 
Posts: 3
Joined: Fri Nov 16, 2012 6:13 pm

Re: RGB LEDs and Ada PCA9685 servo driver breakout issuse

by cannon fodder on Sun Dec 02, 2012 5:51 pm

Hi, an update. It works fine with a common cathode RGB LED, no issuses now :D

cannon fodder
 
Posts: 3
Joined: Fri Nov 16, 2012 6:13 pm