The Texas Instruments ez430-Chronos watch is based on the MSP430 architecture, and features a number of built-in sensors that may be polled wirelessly through an RF receiver. We use LabVIEW to poll the watch and interpret accelerometer data.
The ez430-Chronos, as shipped with its default firmware, transmits accelerometer data packets upon request to a USB RF receiver. The receiver creates a virtual serial (COM) port on the desktop host, and is interfaced with LabVIEW using the VISA serial library.
To begin, install the ez430-Chronos software, and verify that you can interact with the watch in the Chronos Control Center (be sure to stop the access point before running your application in LabVIEW). Note the COM port used by the RF dongle; on Windows machines, this can be found in the Device Manager (Figure 1). Select this COM port when running examples from the project below.
Figure 1: Device manager showing the COM port number of the RF adapter.
Three examples are provided in the project below: simple graphing of the accelerometer, advanced graphing of the accelerometer, and a Theremin emulator. All may be found in the Example Finder by searching for ez430 or navigating to Hardware Input and Output -> Serial. Figure 2 below shows an example of graphing the accelerometer:
Figure 2: Simple graphing of the ez430-Chronos accelerometer.
The simple interface to the RF receiver makes it easy to customize the software on the ez430-Chronos and communicate information to LabVIEW; just send packets via serial and unflatten them in LabVIEW.
1.0 (2010-08-10): Initial release.
1.1 (2011-08-25): Updated to VI Package Manager.
2.0 (2012-07-18): Corrected acclerometer calibration, updated to Silver controls/indicators. Added palettes and examples to example finder.
2.0.1 (2012-07-27): Corrected calibration.
great, i have search aome like this chronos + labview, but i have error,labview display me "errro 5000, poll accelerometer", can you help me?
It would help if you provided more detail; I understand that you had the Chronos Control Center open at the same time you ran the LabVIEW application? After closing the Chronos Control Center, were you able to run the LabVIEW application successfully?
Yes, I did build that VI - based on information I found in the ez430 Chronos Wiki, I send a packet that requests acccelerometer data, and wait until the packet is received on the serial port. The VI checks to see if the packet is received successfully and reconstructs the x, y, and z axis. I think I may scale to +/- 1 as well.
Hi Scott – in the interest in maintaining my community posts, I only post one version of the software online. If you would like, I can e-mail you a 2009 version.