Ask Questions & Offer Ideas -"The Nice Asgard Project"

Summary Time!

Overview of the project – What are you building and what will it look like ultimately?

“Nice Asgard” is a completely unrelated name with credit going to a close friend. The project is to create a home automation system aimed at TV and film lovers with a focus on controlling the viewing environment of the user. The system aims to control the lighting and blind position in a room based on the set mode and the “profiles” set by the user. Initial versions assume a set of defaults that apply to all rooms and cover common scenarios such as normal night use, normal day use, out of the house modes and film watching modes which provide reduced lighting and closed blinds.

The system will be controlled from a users computer (Future iterations could provide control using any WiFi enabled device) with the possibility for control through the end devices using a simplified interface, much like an existing central heating system control panel.

What TI products are being used – simple list with part numbers and why you choose these parts?

• CC3000-FRAM-EMKCC3000-FRAM-EMK
  • Chosen for the WiFi capabilities and the simple interface to a standard MSP430. Used primarily for the simplicity of the design and the included SPI library without the need to create a TCP/IP stack or find a suitable one.
• TPS61042EVM
  • Chosen for the low voltage requirements and ability to control the IC output using  a simple PWM signal over the need to produce an analog signal and suitably filter it for use controlling the lighting. The small size of the EVM and the IC itself make it suitable for producing a compact device for both testing and in a production scenario
• DRV8805EVM
  • Similar to the LED driver, this device was chosen for its low power requirements and small IC size while still providing a suitable capacity for motors capable to raising blinds. This kit was chosen for its ability to handle stepper motors and normal DC motors. The main benefit was the step option which can be used for unipolar stepper motors to provide very precise control when combined with a counter in the main application. Additional features of the IC such as error signals and control pins mean it can be controlled without the need to handle bulky communications protocols.
• CC2530ZDK-ZNP-MINICC2530ZDK-ZNP-MINI
  • The CC2530 was chosen as the ZigBee protocol is the ideal solution for wireless communications in a home automation product and due to personal experience with a similar protocol (XBee). The CC2530 provides a solution that includes all the required stacks and crystals needed to build a ZigBee network, with the only external component (Excluding power and data) is an antenna. This means that adding wireless capability (separate to the existing WiFi capability) to the system is a relatively simple task allowing more time to be spent focussing on the software.

What other tools are being used – CCS, MSP430ware, CadSoft Eagle, etc.  List the tools/software and provide a short summary of how they have helped you.

• CCSCCS
  • CCS provided a tidy and well organised development environment with support for other useful features such as version control and integration with a variety of compilers including the standard MSP430 compiler (and those required by other TI processors). The ability to link different projects together allowed the provided libraries to be compiled as projects and included without the need to continuously move files around.
• MSP430ware
  • This tool was a great benefit by providing a basic API for the more complex functions of the processor such as I2C while also providing a friendly and clear interface for all the basics of the processor including GPIO by reducing tasks to functions and pins to clear names rather than bits and occasionally unclear header files.
• CadSoft EagleCadSoft Eagle
  • Eagle provided a reliable means of designing the circuit and laying out the circuit on a PCB. Using Eagle has meant that PCB designs can easily be exported in an industry standard format for use in producing boards. Due to Eagle being a common piece of software, package files are commonly available and in some cases so are schematics and PCB layouts. This means that producing a reliable design was suitable as the evaluation kit schematic could be adapted to match the design, thus reducing the time spent putting together the supporting circuitry such as the power supply and the system programmer/USB serial interface. The new XML file format used in the recent versions of Eagle mean that it is even easier than before to use the files with version control.
• Git
  • Git, and specifically Github was a great benefit as it provided support for version control and remote backup of the project. In addition to the element14 blog, the repository provides an easy way to share code, track issues and provide information about the project.
• mspgcc
  • On the odd occasion that CCS, linux drivers or Windows has failed to work properly, this package has provided a set of tools capable of performing the basic functions of CCS (Compiling, downloading, debugging) comprehensive enough to allow development to continue on different parts of the project such as developing specific drivers for parts.
• Other misc tools including DMMs, handfulls of LEDs, precrimped leads to act as jumpers and adapters, perf board for adapters.

Overview on “next steps” of the project – What is next?  What are you hoping to complete with some type of timeline?

With the recent OS/CCS disagreement, the aim is to break down the project into several smaller parts and get those working before reintroducing the communication protocol. This will form something of a demo mode to show the outputs, communications and inputs working as separate components. This will also aid with the debug process to narrow down where compiler issues are most likely occurring. With being limited to mspgcc at present, the development of a demo for the LED and stepper motor driver should take a week or two in an ideal world. This may include using the ZigBee development kit as the controllers for each and using the kits coordinator as the main controller. Combining this with the WiFi module may take longer. A final aim is to rewrite the user interface in Processing to match the system design and not rely on the example.

In the long term, the plan is to reintroduce the communications protocol. In terms of a post project long term, the aim is to further develop the system and produce a working prototype using custom made PCBs where possible.

Good update.

You might want to consider using a cable connection between the parts to verify data transfer and low level protocol issues before you go to the Wifi.

That way you can minimize the number of new things you have to look at for any communication problems.

It also gives you a controlled environment by which you can verify each component while using the PC debugging capability.

Just a thought,

DAB

Thanks for the idea DAB. A cable connection should help, slightly easier to probe too. Ideally I'd have access to a scope or something like a Openbench Logic Analyser, might be another trip to ebay to see what is around! Without it however, dumping data to the USB connection should work. A built in debugging feature would be a good feature, a little unnecessary for anything other than the initial setup, but still useful.

No problem.

In all of the projects I worked on in the past, we just found it easier to use direct connections first so that we could unit test with known signals and we could ignore the RF issues after we were sure the devices worked.

The secret to successful debugging is to eliminate as many unknown issues as you can.  Keep it simple and make life easy.

Good luck,

DAB

It is a good habit to get into with communications. Simple is always good, of course there are always things that are always going to be complex and can only be tested as a whole, but it wouldn't be as fun without them right?

It's all fun until the managers and the customers want it to work perfectly and delivered yesterday.

Luckily I learned early to under promise and over deliver.  It helps keep managers in line.

Keep having fun.

DAB

Everyone knows they aren't bugs, they are special features! Always a challenge to keep the managers happy, or in some cases finding them, but that is a different story.

Thanks, I shall keep having fun.