Bluetooth Enables Wireless Datalogging

Figure 1. U1177A Bluetooth Adapter With U1240 Series Handheld DMM

Engineering apps can be a productivity booster while offering convenience in test and related tasks. The apps can replace volumes of textbooks and reference works, provide for remote control of data acquisition, and in some instances, even enable mobile devices to become instruments themselves (such as an audio spectrum analyzer), as I noted in an earlier article.¹

In other instances, mobile apps can augment existing instruments and accessories. That’s an approach Agilent Technologies is taking with its late Q1 introduction of a wireless connectivity solution. It links up to three Agilent handheld digital multimeters to smart phones, tablets, and PCs.

Key to this offering are the $48 U1177A Bluetooth Wireless Adapter and two mobile apps. The U1177A connects to Agilent’s U1270 Series, U1250 Series, U1240 Series, and U1230 Series DMMs by means of the DMMs’ IR port. Agilent specs the adapter’s battery life (two AAA cells) at 30 hours typical of continuous operation (Figure 1).

Android Apps for DMMs

The apps, called Mobile Meter and Mobile Logger, run on Android tablets and smart phones. They turn the Android platforms into virtual instruments that can control the DMMs and access measured data from across a room.

Both apps support up to three DMMs. They can be downloaded for free from the Android market, recently and confusingly renamed the Google Play Store. Mobile Meter is a straightforward app that displays readings on your mobile device, isolated from the harsh environment in which your DMM might be hooked up. You can email readings as text or as an image of the mobile device screen—sending an image, for example, to the Picasa photo-sharing site. You also can send SMS messages.

The Mobile Logger application acquires data over an extended period of time. It lets you set the measurement interval (as long as it doesn’t exceed the auto-off period of the meter or Bluetooth adapter), and you can define the period during which data will be logged. As with the Mobile Meter app, you can share readings via SMS messages and emails. You also can provide for various types of notifications for out-of-limit events: ringtones, vibration, SMS messages, and emails. And, of course, you can export logged data.

Safety and Convenience

At a pre-introduction demonstration of the adapter, apps, and meters, Tak Tsang, business development manager for handheld tools at Agilent’s basic instruments division, said the Bluetooth adapter and apps could be particularly useful for engineers involved in power electronics or automation. They could provide added safety and convenience, removing personnel from high-voltage environments and separating them from moving parts. In addition, the adapter and apps provide for easy verification and documentation: “A local operator can take measurements from a convenient spot and send them to an engineer,” he said.

Figure 2. Data From a U1273A DMM Logged Over a Bluetooth Connection

I tried out the Bluetooth adapter and a U1273A DMM. The U1273A is a 4½-digit water- and dust-resistant meter with a high-brightness OLED display that, somewhat paradoxically, is much easier to read than my smart-phone display. Initially, I put the adapter and meter through their paces using Agilent’s GUI Data Logger software for PCs. My Bluetooth-enabled laptop readily discovered the U1177A and DMM, and I was logging data within minutes (Figure 2).

As this article goes to press, I am experimenting with beta versions of the two Android apps. Agilent’s release notes say the apps have been tested with two Android smart phones (the Google Nexus One and HTC Sensation Z710e, both with Android 2.3) as well as several Android tablets from Acer, Asus, Motorola, Samsung, and Sony. I don’t have any of those platforms and am having issues with my LG G2X Android phone. Visit my blog at www.evaluationengineering.com/blogs/ricks-blog.php for updates.