Blue Maestro Tempo Bluetooth Smart Thermometer: Keeping tabs on your local environment

Blue Maestro Tempo Bluetooth Smart Thermometer

When I first heard about Blue Maestro's Tempo Bluetooth Smart Thermometer (£29.00, or about US$48), it was shortly after I had a conversation with a new friend about creating such a device. Ron, who I met on a recent cruise vacation, had wondered aloud why there wasn't an accessory for the iPhone that would let you check the local temperature. While his idea was more like a plug-in dongle for an iPhone or iPad, I think Ron would be happy with the Tempo Bluetooth Smart Thermometer.


  • Dimensions: 2.87" x 3.54" x 1.1" (73 x 90 x 28 mm)

  • Weight: 3.4 oz. (96.38 gm) with batteries installed

  • Connectivity: Bluetooth Smart (requires iPhone, 4S, iPhone 5, iPhones 5S and 5C and all later models of iPhone; iPad Mini, iPad 3 and all later models of iPad; iPod Touch 5th Generation and all later models of iPod Touch. iOS devices need to be running iOS 6, iOS 7 and later operating systems.)

  • Material: Polycarbonate case with nonslip silicone feet

  • Batteries: Two AA cells (lifetime of about one year)

  • Colors: Blue, Green, Gray, White, Black

  • Accuracy: +/- .2 degrees Celsius

  • Range: -13 degrees/167 degrees Fahrenheit (-25 degrees/75 degrees Celsius)

  • Usable distance: Up to 75 meters line of sight

Design Highlights

For something that you're probably going to use around the house, the Tempo is quite attractive. It has a rounded triangular shape and looks more like a small art object than a temperature sensor. The three nonslip silicone feet ensure that you can place the Tempo on many surfaces -- even if they're not perfectly flat -- and it will stay in one place.

Tempo is waterproof, so if you want to use it as an outside temperature monitor it will work just fine. Note that the low end of the temperature range is -13 degrees Fahrenheit (-25 degrees Celsius), and that a lot of locations in North America got that cold this year...

The two AA batteries are fairly easy to get to -- I was able to pry open the case with a fingernail, and I know it will be a cinch to replace them in a year. There's only one button on the device, a small pushbutton that's placed directly in the center of mass of the Tempo. Push it and a small LED lights up on the bottom of the device, indicating that it's powered up and ready to talk to the accompanying Tempo Thermometer iOS app (free).

Functionality Highlights

Tempo comes with the two AA batteries pre-installed, so setting it up was very easy. I just preloaded the app on my iPhone and iPads, pushed the button on the bottom of the Tempo, and then watched as the temperature came up on the app. Initially it showed the temperature in degrees Celsius -- changing to Fahrenheit was easily accomplished through settings.

The device stores up to 24 hours of temperature readings, so if you happen to be away from your Tempo for a while you can see what the temperatures were like for at least the last day. If you have more than one Tempo, it's simple to rename the devices with a more descriptive title, like "Bedroom", "Kitchen" and the like.

The app shows all of the readings from your various Tempos. There's a small indicator that tells you if the iPhone and device are currently in Bluetooth contact or not, and it appears that the app shuts off its request for Bluetooth connectivity in between requests. Tapping on a specific reading opens up a chart showing either 12 hours (portrait) or 24 hours (landscape) of readings. There's also a "table" button that, when tapped, provides a list of hourly temperature readings that can converted to a PDF or CSV file for emailing. Unfortunately for me, the emailed file was in degrees Celsius, not Fahrenheit. For most of the world, that's not a problem!

There's also a thermometer view that's available in the app -- a tap on a thermometer button brings up a replica of a bulb thermometer with scales in both Celsius and Fahrenheit. The app also allows users to easily set up alarms; perfect if you want notification when a certain temperature is reached.

When I think about my friend Ron's need for an iPhone-centric thermometer, I know that the Tempo would only serve part of his needs. What he really wants -- and I have to agree with him -- is a device that could either be part of an iPhone case or a small dongle that could be plugged into the Lightning or headphone ports for easy on-the-go temperature readings. My hope is that the Blue Maestro team will have a success with Tempo and will work on a smaller, more portable device.


While it's not something you could carry in your pocket in order to make spur-of-the-moment temperature readings, Blue Maestro's Tempo is an attractive and very functional Bluetooth Smart Thermometer that's perfect for home or office use. Blue Maestro has done a good job of making the Tempo easy to set up, and the app is surprisingly full-featured.

Rating: 3-1/2 stars out of 4 stars possible