Seeing distance
differently.

What is LARS?

Traditional limit switches tell a robot when a mechanism has reached a physical position. Conventional distance sensors measure how far away an object is. LARS explores a different approach: using a field of distance measurements to make proximity information more useful to a robot.

At the center of LARS is an 8 × 8 time-of-flight sensor. Rather than returning just one distance, it divides its field of view into 64 zones, producing a two-dimensional map of measured distances. This gives the system spatial information about what is in front of it.

The goal is to make that information accessible through purpose-built electronics and embedded firmware, allowing distance measurements to become useful inputs for robot control and other sensing applications.

From light to information.

LARS uses time-of-flight (ToF) sensing. The sensor emits invisible infrared light and measures the returning signal to estimate the distance to objects within its field of view. Its optics and sensing array divide that field into 64 zones, each providing distance information.

The sensor communicates with the LARS microcontroller, which runs the embedded firmware. The electronics and firmware form the bridge between the raw ranging hardware and the interfaces through which a robot or another application can use the data.

What makes this approach interesting is the difference between knowing that something is nearby and having information about where it appears within a sensing region. Depending on how the data is used, that spatial information can support more flexible proximity logic than a single measurement alone.

The measurements are not a perfect representation of the physical world. Target material, ambient conditions, sensor placement, and measurement validity all matter. Good engineering means understanding those limitations as well as the capabilities.

Designed with FRC in mind.

FIRST Robotics Competition robots combine mechanical systems, electrical hardware, embedded devices, and software under demanding time constraints. Sensors need to do more than produce measurements: they need to fit into an existing control system and provide information teams can actually use.

That makes integration an important part of LARS. Its electronics are built around a dedicated microcontroller, with CAN communication and analog output forming part of the system’s intended interface design. These interfaces provide different ways to incorporate ranging information into a larger robot architecture.

On the software side, WPILib provides the framework FRC teams use to write robot programs. A dedicated LARS software interface can help bridge the device and application code, keeping hardware communication separate from the robot’s higher-level logic.

Potential applications include detecting nearby objects, monitoring mechanism clearance, and incorporating proximity measurements into autonomous routines. The particular behavior depends on the robot code, the sensor configuration, and the interfaces supported by the relevant firmware release.

Three years between an idea and a working system.

Developing LARS meant taking on a problem that extended well beyond selecting a sensor and putting it on a circuit board. A working product required the hardware, firmware, and communication interfaces to operate together as one system.

The development process involved designing custom PCBs, integrating the time-of-flight sensor with a microcontroller, working through hardware and communication problems, and bringing the embedded firmware to a functional state. Individual components could work in isolation without the complete system behaving as intended.

Debugging meant working through those layers methodically: checking electrical connections, investigating communication behavior, verifying sensor initialization, and determining whether a failure came from the hardware, the firmware, or the interaction between them.

It took roughly three years to get LARS working. That timeline reflects the reality of developing a complete embedded system independently: progress was not always linear, and resolving one problem often revealed another. Each setback became part of the process of understanding the system more completely.

LARS ultimately became more than a circuit-board design. It brought together electronics design, embedded programming, sensor integration, and product development in a single project. The experience of making those disciplines work together is part of what defines the system today.

From a working device to a product.

Getting a prototype to function is one milestone. Turning that prototype into something another team can integrate requires a different level of attention.

PCB layout, component selection, firmware behavior, communication interfaces, documentation, and manufacturing all affect whether a design can be reproduced and used reliably. A product also needs a clear explanation of what it does, how it fits into a larger system, and where its limitations lie.

LARS is being developed through Pennington Laboratories with that transition in mind: from an independently engineered embedded system toward a documented, manufacturable product for robotics and other applications where distance information can be useful.

The work continues beyond the first successful measurement. The objective is to make the underlying technology practical for other people to build with.