EtherCAT Arduino Shield by Esmacat (EASE)
Feature Highlights
Raspberry Pi
Codesys
Hardware Connections
Required Libraries
Software
Running the Master Code
Results

Published February 13, 2020 © GPL3+

Raspberry Pi with Codesys PLC UI Controlling an Arduino

Use a Raspberry Pi with Codesys to control the LED on the EtherCAT Arduino Shield by Esmacat attached to an Arduino Uno.

BeginnerProtip1 hour8,721

Things used in this project

Hardware components

Raspberry Pi 4 Model B

Raspberry Pi to be used as EtherCAT Master with free open-source EtherCAT master code provided by Esmacat

Raspberry Pi Power Supply

Esmacat Master S

Optional EtherCAT Master

Esmacat Master C

Optional EtherCAT Master

Arduino UNO

EtherCAT Arduino Shield by Esmacat (EASE)

Ethernet Cable, Cat6a

Power over Ethernet (POE) Injector

DC Adapter

For powering the POE injector

Software apps and online services

Arduino IDE

Codesys

Software to program the Master PLC.

Story

You can read more about this and other Esmacat tutorials on the official Esmacat website. Check out our other Hackster.io demos as well.

Detailed documentation of the codes and steps for this tutorial can be found here.

Check out our EASE Crowd Supply Campaign Page: https://www.crowdsupply.com/harmonic-bionics/ease

Overview:

In this tutorial, you will learn how to set up a Raspberry Pi with Codesys to act as both a PLC and an EtherCAT master. It will be used to control the on-board LED found on the EtherCAT Arduino Shield by Esmacat (EASE) Slave device that is attached to an Arduino Uno.

First, some general information about Raspberry Pi and Codesys is discussed.
After learning to set up the Pi and Codesys, you will learn to implement a practical project to blink the onboard led on EASE based on user input by updating EASE registers using Codesys.

EtherCAT Arduino Shield by Esmacat (EASE):

EASE is an EtherCAT slave that connects to an EtherCAT master (PC/ Laptop/ Dedicated Master devices like the Esmacat Master S and Esmacat Master C.) It can be stacked on top of Arduino, other MCU boards with an Arduino Uno form factor, and shields. This shield allows high-speed communication with an industry-standard EtherCAT protocol for high-performance robotic applications. Esmacat's simple to use Arduino and Mbed libraries allow for easy coding on the base board and Esmacat's free open source master software has a high-level abstraction so users can run applications within minutes!

1 / 2 • EASE

Feature Highlights:

EASE connects Arduino boards, Arduino-like boards, and Arduino Shields for large-scale applications.
High speed communication (200Mbps, 200x faster than CAN bus) is supported with EtherCAT which is an industrial-standard fieldbus for automation.
The EtherCAT hardware/software is present only on EASE so there is no performance lost on the MCU base board
EASE has the form factor of Arduino Uno, and thus can take the advantage of the Arduino ecosystem.
Daisy chain connection between multiple EASE simplifies the topology of wiring.
Power-over-EtherCAT (POE) technology reduces the number of required wires and power outlets.
The data packet between Arduino Board and EASE is communicated via SPI, allowing EASE to be compatible with many different types of boards including Arduino boards and MBed boards.
Arduino and Mbed developed by Esmacat library allow users to easily develop code between the base board and EASE within minutes.
This shield has 8 registers that can be used to send/receive data between devices through the EtherCAT master via Ethernet cables attached to the shield.

More info: https://www.esmacat.com/ease

Suggested Reading: EASE Datasheet.

Raspberry Pi:

Raspberry Pi is a tiny, dual-display, low-cost desktop computer that is used widely in robot brains, smart home hubs, media centers, as a networked AI core and factory controllers. It can also be used as an EtherCAT master just like a Laptop/PC. However, it should be noted that the Pi is a Linux based computer.

Codesys:

Codesys Logo

CODESYS is a PLC programming environment that is used widely by many industrial automation companies like Beckhoff, Bosch, Wago, etc. You can program in Codesys using the traditional Ladder Logic or using Structured text and Continuous Flow Chart (IEC 61131-3 standards).

For this tutorial, the following packages must be downloaded from the links below,

Note: You must create a Codesys account in order to download the above files.

Note: The ESI (EtherCAT Slave Information) of EASE must be added to Codesys to use it in the program. Refer to the documentation (section 3.2.2) below to get detailed steps for the initial setup of Codesys for Raspberry Pi.

Hardware Connections:

The primary hardware components include,

EtherCAT slave (EASE with Arduino)
EtherCAT Master (Raspberry Pi)
Power Over Ethernet (POE Injector)
Ethernet cable
DC Adapter (for POE) and

Since EASE uses a POE injector, there is no need to power the Arduino board separately. EASE can power the board andany other boards connected through EtherCAT!

The connections are as shown in the two schematics attached in the "Schematics" section of this tutorial. "The Hardware setup schematic" gives an overview of the connections to be made while the "Physical connection schematic" shows the setup once all the connections are made.

Note:

Make sure the Ethernet connections are fit tightly into the sockets. (Loose connections may lead to the slave device not being recognized.)

Required Libraries:

An EASE Library for Arduino to communicate with the Arduino subsystem.

The link to the library has been included under the Code section. Download the library and add it to the Arduino IDE (Sketch-> Include Library-> Add.ZIP library and select the file) to get started with the coding part.

Suggested Reading:Getting started with EASE.

Software :

The software required for this tutorial involves coding for

the Esmacat Master and
the Arduino.

Programming the Esmacat Master:

Open the Codesys software and import the.project file downloaded from the Code section and build the source code.

Suggested Reading: Section 8 Getting Started with EASE & Codesys.

Coding the Arduino:

Open the Arduino IDE and create a new sketch file. The complete code for this tutorial is available under the Code section named "EASE_codesys_onboard_led".

Compile and Upload this code into the Arduino board connected with EASE.

Note: Make sure you check whether the Board and Port are chosen correctly in the IDE.

Running the Master Code:

When running the master code you get a result similar to the following on the Codesys environment (with a graphical UI showing the update of registers in EASE).

Master Code Execution

Results:

By now you have successfully programmed the Arduino boards and the Esmacat master! The visualization tool in Codesys gives a graphical UI to control the on-board LED in Arduino similar to the GIF attachment at the start of the tutorial and the YouTube video below.

Final Notes: A detailed step by step tutorial for this project can be found in the document attached below.

Suggested Reading: Getting Started with EASE & Codesys.

Code

/*
  Codesys Onboard LED Control

  This sketch does the following:
  1) Controls the onboard led in Arduino using input from the EtherCAT master (Pi) using Codesys.
  2) Depending on the value updated in one of the EASE registers it does the following
      2.1) If the register value is 0 the led is turned off.
      2.2) If the register value is greater than 0, the led is turned on.      

  created 27 Jan 2020
  by Harmonic Binonics Inc. (https://www.harmonicbionics.com/).  
*/

#include <Esmacatshield.h>      //Include the Esmacat Arduino Library

# define ARDUINO_UNO_SLAVE_SELECT 10      // The chip selector pin for Arduino Uno is 10 

Esmacatshield ease_test(ARDUINO_UNO_SLAVE_SELECT);      // Create a slave object and specify the Chip Selector Pin

// Required variables Initialization
int led_state = 0,led_pin = 8,delay_time = 1000;
int ease_registers[8];   // EASE 8 registers

void setup() 
{
//  Serial.begin(9600);   // Begin Serial communication at the specified baud rate
  pinMode(led_pin,OUTPUT);
  ease_test.start_spi();   // Start SPI for EASE
}

void loop()
{
  ease_test.get_ecat_registers(ease_registers);   // Update EASE registers with new data
  led_state = ease_registers[0];   // Assign register 0 value to variable
  delay_time = ease_registers[1];  
//  Serial.print("LED State is ");   
//  Serial.print(led_state);   // Print variable to the Serial monitor (for debugging)
  if(led_state == 1)
  {
    digitalWrite(led_pin,HIGH);
    ease_test.write_reg_value(1,led_state,true);
    delay(delay_time);
    ease_test.write_reg_value(1,led_state,false);
  }
}

Credits

Esmacat

11 projects • 16 followers

Esmacat is an easy yet powerful EtherCAT solution for robotics. Our EtherCAT tech allow users to run EtherCAT applications in minutes!

Raspberry Pi with Codesys PLC UI Controlling an Arduino