Performance tests in case of rs485 failure

In my home automation project with Arduino and Android I always paid special attention to communication failures. These might happens for many reasons and the system has to deal with them.

In particular, in the following video I was interested to show you some test I made in order to assess whether the information presented by the touchscreen panel will be displayed whenever available.

The red led indicates that the Arduino is processing a modbus request. As you can see, it stops blinking when the bus 485 is interrupted and immediately after the connection has been restored, it restart to work. Indeed, take look at the bulb icons in the monitor. When the bus is restored, the bulb status will be updated.

The description of the project and the source code are also available. Take a look!

As usual, comments are well appreciated! :)

Android Arduino Communication through Modbus and Rs485

In this post I’d like to describe you a project I’m working on that consists of connecting an Android multi touch panel to one (or more) Arduino slave(s) using modbus protocol and RS485.
Even though the idea of this project could be applied in many fields, I chose to contextualize it in a typical smart home context: a touch display that dims lights, shows temperatures and bulbs statuses.


The nice feature of the Android multi touch panel I used is that it has many interfaces such as Ethernet, RS485, RS32 and I²C as well.
I expressly selected RS485 because Arduino-based microcontrollers are not ready for Ethernet yet (even though some examples still exist but without great success). Indeed, RS485 is a well known standard that has been widely used in the indus­trial con­text and in building automa­tion appli­ca­tions. It is a half-duplex, 2-wires, low noise bus that allows high speeds and remote devices connection (up to 1200 meters).
Furthermore, modbus is a serial communication protocol, developed for industrial applications, open and easy to deploy and maintain. I used modbus RTU, but other variations of the protocol still exist though. Continue reading

Industrial Automation and Future Trends

Industrial Automation remote I/O moduleThere is debate on the feasibility of employing Android on Industrial Automation applications.
Big companies contend the market share and most of the time constrains customers to use their proprietary software.

The world is changing and the Internet allows users to benefit from almost infinite availability of information, technical specifications and even to find people that freely share their knowledge and expertise.

Our vision is that in the close future, more industrial automation applications will benefit from the open community and they will lay the foundation to a new revival of this sector.

In this post, I want to show you how the integration of Android in industrial automation applications is possible. I also noted that is surprisingly straightforward.
Continue reading

Android Industrial: AC Drive over rs485

The following video represents an example of HMI in Industrial applications. In particular, in this project I used an Android multi touch that runs on Cortex A8 at 1Ghz and show how it can greatly control an AC drive. Specifically, I used a Allen-Bradley adjustable frequency AC drive.

The Android UI on the touch screen device allows to:

  • Start/Stop the motor
  • Set the direction (forward, backward)
  • Manage the output relay
  • Control the status of the digital inputs
  • See the parameters such as the current, frequency and output voltage
  • Set the motor frequency

You’ll find the source code and complete specifications of the project on my github channel. Don’t miss to check it out also our wiki section! As usual, comments are welcome :)