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I'm trying to follow an adafruit servos tutorial to control servo motor from my raspberrypi.

My PCA9685 seems on (the green led is power up) and i attached two servos to it. I cabled as in the tutorial, so the VCC is attached to the arduino with the ground (I think i so other possibilities). I made the alimentation myself from a 5V 0.4A.

PCA9685

Rpi&PCA9685

The pins have connected are:

 _______________
|..X..........
|XXX..........
|

When i use i2cdetect i got empty adresses:

pi@raspberrypi:~/Adafruit_Python_PCA9685 $ i2cdetect -y 1
 0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
 00:          -- -- -- -- -- -- -- -- -- -- -- -- --
 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 70: -- -- -- -- -- -- -- --

So i'm not sure if it's

  • my welding that are bad (i didn't weld every pin)
  • my alimentation that isn't strong enough
  • or if i'm missing something else.

Thanks alot.

EDIT:

I tried running:

echo -n 1 > /sys/module/i2c_bcm2708/parameters/combined

and in /etc/modprobe.d/i2c.conf :

options i2c-bcm2708 combined=1

and doing a reboot, but it didn't work and i still have no adresses showing up.

Result after installing :

pi@raspberrypi:~ $ sudo apt-get install pigpio python-pigpio python3-pigpio

pi@raspberrypi:~ $ pigs mg 2 mg 3
4
4
  • There's a line you may have to type in terminal to get I2C to work -- see this forum post: raspberrypi.org/forums/… – calcium3000 Jan 3 '17 at 15:44
  • sudo sh -c 'echo -n 1 > /sys/module/i2c_bcm2708/parameters/combined' – calcium3000 Jan 3 '17 at 15:44
  • Why do you have a wire connected to OE? If you are externally driving OE you will change the logic for the output pins. Leave it float, it's pulled up on the board. – Jack Creasey Jan 3 '17 at 17:11
  • I'm not and it's not connected, it's the photo that's show that. My connected pins are GND - SCL - SCA - VCC – Lumy Jan 3 '17 at 17:17
  • The device is not correctly connected to the Pi. We need a photo showing the I2C wires between the Pi and the device. – joan Jan 3 '17 at 17:23

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