How can i connect two adafruit 16-channel 12-bit PWM/Servo Driver I2C interface (pac9685) to Raspberry or Arduino

Question

I need to control 24 servos but I do not know how to do with I2C. I saw some componentes that do it with USB, but I need to do it with I2c.

I am working in a robot with 8 legs and 3 degree of freedom in each leg, so i need to connect and control 24 servos to any arduino board, could be possible with an arduino mega and a sensor shield like that show in https://arduino-info.wikispaces.com/SensorShield but I want to do it using two "16-channel servo drive" like this https://www.adafruit.com/product/1411, each of these can control 16 servos using only 2 pins from the board and it is “Chain-able” design so i could connect 2 of this to an Arduino Uno board or Raspberry but I do not know how to do. Any one can help me with I2C chains connections.

Answer 1

You will need to control it vai I2C .

There are libraries for pca9685 , if you want to control it vai an Arduino(Micro controller ) https://github.com/Reinbert/pca9685

If you want to use with a RPI , you can directly use python libraries and I2C vai GPIO pins . https://github.com/voidpp/PCA9685-driver

I too am trying to build a hexapod/quadpod using tiny mg90 servo motors and 3d printed parts .

I am trying to get all of this ROS enabled so that we can perform more advanced level operations using this .

Anyways , for now i am trying to figure out how to operate the servo motors just for a 6 axis robotic arm i am building .

Answer 2

Adafruit has versions for both the Pi and the Arduino. Right in the web page describing each product they state you can stack up to 62 shields (or hats). Nobody would really do that, but it is obviously made for such abuse.

You'd have to either use right-hand headers or else solder the ends of the servo wires to the board.

I do with they'd been able to get 18 on a board because hexapods require 18. But then I'd always want another one. They're like Lays potato chips. :)

And Adafruit has the libraries for this.