Automating External Monitor Positioning Using Bluetooth Technology

Proud to share this article written in collaboration with my talented colleague Prabhuram Natarajan

In today’s flexible work environments, users often switch between various monitor setups—connecting their laptops to different external monitors at home, work, or co-working spaces. One persistent challenge with this routine is that the laptop doesn’t automatically recognize the position of the external monitor relative to the laptop.

Every time a new monitor is connected, users are forced to manually drag and align the virtual position of the external monitor in their display settings, setting up the correct extended desktop view. This process becomes cumbersome, especially when it's a recurring task as flexible workspaces are increasingly common.

In this blog, we propose an innovative solution using?Bluetooth technology?to automate the identification and positioning of external monitors, eliminating the need for manual setup.

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The Problem: Manual Alignment of External Monitors

When you connect an external monitor to a laptop, the laptop generally recognizes it as an additional display. However, it cannot automatically determine the monitor's spatial orientation (e.g., whether it's positioned to the left, right, or above the laptop) without user input. Even laptops that can detect the monitor's position based on the port used may still require some manual adjustments for accurate alignment.

This results in the following issues:

1. Manual effort:?Users must manually adjust the position of the virtual monitor in display settings.
2. Frequent repositioning:?When connecting to different monitors in different setups, this manual configuration becomes a recurring annoyance.
3. Wasted time:?Especially for workers who frequently change setups, the time spent adjusting monitor positions adds up and disrupts productivity.

Imagine the convenience if the laptop automatically understood where the external monitor was placed and set up the extended desktop seamlessly. Enter our Bluetooth-based solution.

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High-Level Solution: Using Bluetooth to Automatically Detect Monitor Position

Our proposed solution leverages?Bluetooth Low Energy (BLE) technology?to automate the detection of an external monitor’s position relative to the laptop. The idea is to utilize a?BLE beacon?on the monitor and two Bluetooth receivers on the laptop to determine the monitor’s location. Here’s how it works:

Components:

1. BLE Beacon: This small device will be mounted on the center of the external monitor.
2. Bluetooth Receivers: Two receivers will be placed on the left and right sides of the laptop to measure Bluetooth signal strength.

Working Mechanism:

1. Beacon Broadcasting: The BLE beacon on the monitor continuously broadcasts signals.
2. Signal Reception: The two Bluetooth receivers on the laptop pick up the signals from the beacon.
3. RSSI Calculation: The receivers will calculate the Received Signal Strength Indicator (RSSI) from the beacon. The RSSI value will differ based on the distance of each receiver from the beacon.For example, if the external monitor is on the right side of the laptop, the RSSI value will be stronger on the right-side receiver and weaker on the left-side receiver.
4. Position Determination: Using the relative RSSI values, the system can triangulate the position of the external monitor with respect to the laptop (left, right, above, etc.).
5. Automatic Alignment: The laptop then automatically adjusts the external monitor's virtual position in the display settings based on its real-world location.

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What is a Bluetooth Beacon?

A?Bluetooth beacon?is a small wireless device that operates using?Bluetooth Low Energy (BLE). It broadcasts signals, and devices with Bluetooth capabilities, such as laptops or smartphones, can detect these signals.

The beacon sends out a?UUID?(Universally Unique Identifier) that helps identify the device. Receivers, such as the Bluetooth receivers on the laptop, listen for these signals, which carry RSSI values that help calculate the distance between the beacon and the receiver.

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Calculating Distance

The distance between the beacon and the receiver can be calculated using the following formula:

Where:

• MeasuredPower?is the RSSI value when the receiver is placed 1 meter from the beacon.
• InstantRSSI?is the current RSSI value received by the receiver.
• N?is an environmental constant (typically, a value of 2 is used in most cases where the environment remains consistent, as in this case where both the laptop and monitor are relatively stationary).

This formula helps measure how far the monitor (with the beacon attached) is from the laptop. By using two receivers on either side of the laptop, the system can compare the distances and deduce the relative position of the monitor.

Triangulation for Position Detection

Once the distances are calculated using RSSI, the system can use triangulation principles to determine the exact position of the monitor relative to the laptop. If we imagine the three devices (the monitor beacon and two laptop receivers) as forming a triangle, the system can calculate angles and distances.

Triangulation Formula

For a triangle with sides?a,?b, and?c?where the angles opposite these sides are?α,?β, and?θ?respectively, the relationships between the sides and angles are given by:

This mathematical approach allows the system to calculate the exact position of the monitor beacon in relation to the two Bluetooth receivers on the laptop.

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Why Bluetooth Low Energy (BLE)?

Bluetooth Low Energy is an ideal technology for this solution because:

• Low Power Consumption: BLE is designed for minimal power usage, making it perfect for devices like beacons that are always broadcasting signals.
• Widespread Support: Most modern laptops already come equipped with BLE, meaning this solution can be integrated without the need for additional hardware in many cases.
• Accurate Proximity Detection: BLE's ability to provide RSSI values makes it possible to estimate the distance and relative position of a device (in this case, the external monitor) with reasonable accuracy.

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Benefits of This Approach

1. Seamless Experience: Once implemented, users no longer need to manually adjust the position of their external monitor in display settings. The process becomes entirely automatic.
2. Time-saving: Workers who frequently change setups can save valuable time each day by eliminating this repetitive task.
3. Better Flexibility for Remote Work: With more people adopting flexible work environments, this solution will enhance productivity by making the transition between different monitor setups easier.
4. Energy Efficient: Since BLE is a low-power technology, the energy consumption by the beacon and Bluetooth receivers will be minimal.

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Challenges and Considerations

While this solution is promising, there are a few challenges and considerations to address:

1. Calibration: The system may require initial calibration to ensure the correct detection of the monitor’s position. Factors such as obstacles, interference from other devices, or distance between the laptop and monitor could impact RSSI accuracy.
2. Multiple Monitors: Handling multiple external monitors could be more complex and may require advanced signal processing algorithms to differentiate between signals from multiple beacons.
3. Hardware Requirements: While most laptops have Bluetooth capability, the BLE receivers on either side of the laptop might require additional hardware components in some cases.

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With the rise of flexible workspaces and the increased use of external monitors, automating the process of positioning external monitors can greatly enhance user experience. Using?Bluetooth Low Energy technology?to detect the relative position of monitors is an efficient, cost-effective, and user-friendly solution that addresses the frustration of manual setup. By implementing this solution, we can provide users with a seamless and productive experience, making extended monitor use simpler and more intuitive.