Description

The Raspberry PI is an amazing little computer, but it is not expected to directly manage a servo-motor. The Servo Hat is an expansion card for Raspberry PI which allows to fly until ' 16 servo motors or LED with a 12-bit precision. In addition this shield uses an i2C with only two pines (SDA and SCL) necessary affair, which allows to use it further other shields without monopolizing too much pine.

This shield has a selectable address by welding, which allows to use up to 62 shields generating total 996 PWM outputs. It possible to use other sensors or eripherique I2C that does not use the base address 0 x 40.

Based on the PCA9685 circuit here is some advantage:

• It has an internal clock, you do not have to provide a PWM value permanently, once home, remember the chip and continued to vary the output.
• 6 addresses selectable to chain 62 shields.
• Adjustable PWM frequency 1,6 kHz
• 12 bits of resolution per channel, is a period of 4µS at 60 Hz
• Configurable in push-pull or open-drain output.

Some present extras on the Servo Hat:

• Possibility to use a Terminal screw for the external power supply (supplies)
• Protection of polarity on the screw terminals.
• Two LED of presense of voltage (VDC and + V)
• Block of 3 pins per channel to directly connect a servo-motor, the blocks are regrouppe by 4.
• Possibility to use curved connectors to be able to stack several cards (not provided)
• Oving to weld a big capacitor on line V + if needed.
• Resistances of 220Ω are welded on each output PWM to protect them and to be able to drive LEDS directly.
• Jumper weldable to select the address of the Servo Hat.
• Prototyping area free to add what you want.

The product is sold assembled and tested with:

• 4 X 4 x 3 connectors for connecting the servo motors or LED
• 1 X terminal block screw 2 points for external power supply.
• 1 X Conecteur 2 X 20 point for RPI part.

Features

• Dimensions (without the headers and the terminal block screw: 65mm x 56mm x 13mm / 2.6 "x 2.2"x 0.5")
• This I2C card use 7-bit addresses between 0 x 60 - 0x80, selectable by soldering jumper
• Planned for Raspberry model A + or B +, but compatbile model A or B using a connector 2 X 13
• Requires an external power supply 5V to 6V
  

• Documentation:

• Adafruit 16-Channel PWM/Servo HAT for Raspberry Pi