Bluetooth to deter Power Tools theft

Thieves are increasingly stealing power tools from retail outlets and selling them online at lower prices. Recently, Home Depot announced that it has started using Bluetooth technology to prevent theft of power tools from its outlets. However, the retailer provided scant details. This article explains a possible implementation of theft prevention using Bluetooth technology at a retailer.

Retail outlet to use Bluetooth to prevent theft

In March 2021, police arrested a thief for stealing 17K USD worth of machine tools from Home Depot in Florida. The retail outlet observed that a power tool is valuable only if it can function. Hence the retail outlet will use the Bluetooth IC embedded inside the power tool to activate the tool after the customer has purchased the device.

For several years, power tool vendors, e.g., Bosch, Milwaukee, etcetera, have embedded Bluetooth chips in their cordless tools. The benefit is that the user can monitor the battery status, enable/disable their power tools, adjust settings via a smartphone app.

Customers employ a power tool to do a domestic chore or commercial job, e.g., drilling, grinding, etcetera. A typical cordless power tool uses an electric motor, e.g., a Brushless DC motor (BLDC), to rotate its output shaft.

Typically a power tool supply chain consists of a manufacturing facility, a distributor and a retail outlet. The OEM will lock the power tool in its manufacturing facility and ship it to the distributor. The cloud server is connected to the locking, unlocking device and POS in the supply chain.

Locking and unlocking the Power tool

Locking the power tool

First, the locking device receives unique information such as the tool’s serial number, product model, radio Bluetooth address, etcetera. The locking tool combines this unique tool information with other parameters such as current date & time and can apply a hash algorithm to generate a unique locking code.

Second, the locking device communicates this locking code to the power tool over Bluetooth low Energy (BLE). Third, the power tool stores this locking code in its memory and will prevent the tool’s motor to operate.

Fourth, the cloud also receives this lock code and stores it on the server. The retail outlet will receive the tool-specific lock code from the manufacturing facility via the cloud server.

Next, the factory ships the power tools to the retail outlet. The retailer displays the power tools in a locked state. The customer selects the power tool and takes it to the POS for payment.

A possible implementation: Customer activates the tool at home

After payment, the retail outlet prints the tool-specific unlock code on the customer’s receipt. Alternatively, the retail store can also email / SMS the specific unlock code to the customer after purchase.

At home, the customer power up the drill (and its Bluetooth radio) and then provides the unlock code through the drill’s mobile app over Bluetooth low energy to activate the power tool. The app will refuse to start the device after a few failed attempts to deter the thief.

Note that there are multiple possibilities to unlock the power tool. This article cover one potential implementation.

It’s still early days to conclude the effectiveness of this pilot program. Further, Home Depot has shared meager details of its implementation. Nevertheless, this Bluetooth use case for theft prevention is intriguing, and we will learn more about this application in the coming months.