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! :)

New Arm Cortex A8 MCU touch screen

Arm powered logoIn this post, I’d like to share with you a video preview of the latest development board (Single Board Computer) with Android OS that I’m working on. It has a capacitive 7″ touch screen. Compared to the MCU ARM used in a previous home automation project, this SBC is shipped with an ARM Cortex A8 MCU at 1 GHz and with no doubt it is very powerful and fast.

In addition to Android (up to ver 4), it supports WinCE and Ubuntu. It has 512MB DDR2 on board SDRAM, 4GB of iNand flash memory, Ethernet, serial ports (3x Rs232, Rs485, uart, i2c, spi) and 4x USB Hosts, HDMI and TV OUT, 2x SD, G-sensor, GPS and GPRS interfaces and many more. For those of you interested to use this ARM Cortex in industrial automation, I designed a native Android library that manage the rs485 modbus protocol.

Take a look at the complete technical specifications. I’m working to share the Android projects I used for smart homes and industrial automation. If you find it interesting and you think that it could be a valid solution to your needs, please consider to buy it :)

As usual, comments are welcome!

Android Project for Smart Home Automation

Android project smart home automationThe project I’m working on is about making a home automation system using an ARM Cortex A8 1Ghz Android based development board and some Arduino slaves that communicates using rs485 and modbus.
In the previous article, I wrote about how to create Arduino slaves that wait and answer for modbus requests. Indeed, I also made some performance tests in case of rs485 communication failure. Please take a look at the end of the article.

It is now time to present how to write an Android project that acts as a master and communicates with slave devices.

The nice thing of this design is that the logic that controls the smart home system is not constrained to be on the masters’ node. Instead, it can be distributed across all the Arduino devices. Indeed, since rs485 and modbus protocol were designed for industrial environments, this project could be easily used in industrial automation.
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