Servoberry V 1.0

ServoBerry V 1.0 is an extension board for Raspberry Pi derived from the shield Adafruit 16-Channel Servo Driver, and it is an Open Hardware Design. It has two functionalities: a PWM led/motor driver IC and an ADC.

servoberry_on_raspberry

 

The PWM is the PCA9685 an I2C-bus controlled 16-channel LED controller. Each LED output has its own 12-bit resolution (4096 steps) fixed frequency individual PWM controller that operates at a programmable frequency from a typical of 24 Hz to 1526 Hz with a duty cycle that is adjustable from 0% to 100% to allow the LED to be set to a specific brightness value. All outputs are set to the same PWM frequency. The LED output driver is programmed to be either open-drain with a 25 mA current sink capability at 5 V or totem pole with a 25 mA sink, 10 mA source capability at 5 V. The MCP3008 device is successive approximation 10-bit Analog-to-Digital (A/D) converters with on-board sample andhold circuitry. The MCP3008 is programmable to provide four pseudo-differential input pairs or eight single-ended inputs. Communication with the devices is accomplished using a simple serial interface compatible with the SPI protocol. The devices are capable of conversion rates of up to 200 ksps.

servoberry_two_motor_bottom

You can see a couple of PWM motors connected to ServoBerry board.

servoberry_two_motor_top

 

It is possible to preorder this board for only 25€.

ServoBerry with CodeSys

It is possible to use servoberry board with codesys application for raspebrry.

Instructions:

  1. SPI enabled
  2. Comment the following line in config.txt:

#dtoverlay=mcp2515-can0-overlay,oscillator=16000000,interrupt=22

  1. Install CODESYS Control for Raspberry Pi SL for more details go to: http://store.codesys.com/codesys-control-for-raspberry-pi-sl.html.

It is possible to use the free version that work for 2 hours.

  1. Install CODESYS Development System V3.5 SP7 Patch 5 for more details go to: https://www.codesys.com/products/codesys-engineering/development-system.html
  2. Open in CODESYS Development System V3.5 the project Servoberry.project.
  3. if the device is in the same network with your programming PC. Select it and run “log in” from the menu “Online”. Then start the application with F5.
  4. Start an internet browser (possibly also on your smartphone) and connect to <Network Address raspberry>:8080/webvisu.htm

 

Software examples

Download Wheezy raspbian Prerequist:

1. SPI enabled
2. wiringPi installed

Comment the following line:

dtoverlay=mcp2515-can0-overlay, oscillator=16000000,interrupt=22

in the /boot/config.txt file to enable the SPI0.0 dev used to communicate with servo PWM driver.

Download ServoBerry-Test

ServoTest_screenshot

Download

Schematic PDF

EalgeCAD File

ServoBerry Datasheet

 

Certification Disclaimer

Leave a Reply

Your email address will not be published. Required fields are marked *