By John Dodge

By John Dodge

CHICAGO (CBS) — As Friday afternoon wanes, thoughts turn to meeting friends for a few well-earned cocktails and conversation.

Relaxing at an outdoor venue, the weather is serene, the company lively, and Happy Hour turns into much than an hour.

Now the uncertainty comes into play: Am I OK to drive?

A new device aims to answer that question without a doubt and potentially keep over-served adults off the road.

It’s called Drink Mate, and it plugs into Android phones to give users their blood alcohol content.

It is billed as the smallest breathalyzer in the world.

The device works like this:

> Plug DrinkMate into your Android phone.

> Follow the app’s instruction to blow into DrinkMate.

> BAC results are displayed instantly.

(Credit: Kickstarter)

(Credit: Kickstarter)

The developers at Edge Tech Labs say the reading is accurate to within +/- 0.01% BAC at a BAC of 0.02%.

The sensor’s maximum BAC is 0.20% BAC, which is 2.5 times the legal limit of .08 in Illinois.

The DrinkMate is being promoted through a Kickstarter campaign. Supporters who donate $25 are guaranteed delivery of one DrinkMate.

The developers have tested the device successfully in these phones:

Samsung Galaxy S3, S4, and S5
Samsung Galaxy Note 3
Motorola Moto X
Asus Transformer Prime, Infinity

It is being beta-tested, but is expected to be compatible with:

Google Nexus 5 and 7
Sony Xperia Z1 and Z2
Phone or tablet running Android 3.1 or later with USB host capability.

The lead developers of DrinkMate, Shaun Masavage, an electromechanical engineer, and Mack Redding, an engineer and physicist, say they will develop a more-costly iPhone version if the Android campaign is a success.

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