Short-Range Single-Point DToF Sensors for Industrial & Robotics
Most of what we've written about on this site covers long-reach applications — night vision, drones, handheld optics — where the interesting engineering problem is squeezing kilometres of range out of a few grams. Industrial and robotics ranging is a different problem entirely: the distances involved are often centimetres to a few hundred metres, the update rate needs to be high, the power budget is frequently battery-constrained, and — critically — you usually already know roughly where you need to point the sensor.
Single-point vs scanning
A scanning LiDAR sweeps a beam (or an array of beams) across a field of view and builds up a point cloud — powerful, but it costs more, draws more power, and adds mechanical or MEMS complexity you don't need if your application only ever needs one number: the distance along one fixed axis. A single-point DToF sensor gives you exactly that — one beam, one reading per shot — at a fraction of the cost, power and integration complexity. For a huge share of industrial and robotics ranging problems, that's not a compromise; it's the right tool. A few examples: a fixed down-look sensor on an AGV for drop-off/cliff detection, a proximity or homing sensor on a robot arm end-effector, a bumper-mounted forward sensor for collision avoidance, an object-presence or height-check sensor on a conveyor line.
Why near-zero minimum range matters here
Long-reach modules are optimized for a minimum range of a metre or more — fine for handheld optics, useless for a robot that needs to know if it's 5 cm from a wall. Our integration-series modules are built the other way round: the SPD1200S2 and SPD1200Z2 both start their measurement range at 0.2 m, extending out to 1,200 m (1,500 m at night). That near-zero minimum is what makes them usable as close-quarters proximity and clearance sensors, not just long-distance rangefinders pressed into a job they weren't designed for.
| Model | Size | Weight | Range | Frequency |
|---|---|---|---|---|
| SPD1200S2 | 24.6 × 14.45 × 26.3 mm | ≤ 10 g | 0.2–1,200 m (1,500 m night) | 4–15 Hz adaptive |
| SPD1200Z2 | 7.2 × 14.8 × 28.2 mm | ≈ 6 g | 0.2–1,200 m (1,500 m night) | 2–20 Hz adaptive |
The power argument
A mobile robot or an AGV running on batteries can't afford a sensor that draws multiple watts continuously — that's the kind of budget a mechanically scanning LiDAR often needs. Single-point DToF modules in this class sit well under 1 W in normal operation and drop to sub-milliwatt sleep power when idle, which is why they can run continuously on a mobile platform without meaningfully denting runtime. If your application only needs a periodic check rather than continuous streaming, the sleep-power figure is usually the more important spec to look at than the peak operating figure.
Mechanical fit
Square and rectangular envelopes — like both modules above — mount more predictably into a flat chassis panel or an automation fixture than a cylindrical tube does; there's no rotational alignment to get right, and the mounting footprint is easier to lay out in a mechanical drawing. That's a small detail, but it matters at integration time far more than it shows up on a spec sheet.
Getting data into your control system
Output is the same UART-TTL frame used across the entire catalog, which means any robotics-class microcontroller or single-board computer — an STM32, an Arduino-class board, a Raspberry Pi — can read it directly with a standard serial driver. There's no proprietary SDK or driver stack to integrate; see our UART-TTL integration guide for the frame format and a minimal parse loop.
Sensor fusion, not sensor replacement
Single-point DToF ranging is rarely the only sensing modality on a robotics platform — it typically sits alongside encoders, IMUs, bump switches or a camera, contributing the one measurement none of those give you cleanly: a calibrated absolute distance along a known axis. A drop-off sensor doesn't need to understand the floor's texture the way a camera-based system might; it needs a fast, reliable "how far to the surface below me" number, and that's exactly what a fixed-axis DToF point sensor is built to deliver without the compute cost of processing an image or a point cloud. Treating it as one clean input into a wider sensor-fusion stack, rather than trying to make it do a scanning sensor's job, is usually the right architectural call.
Validating before you commit to a design
Because these modules are cheap and low-power enough to prototype with easily, the practical path is to bring up one sample on your actual target surface and mounting geometry before committing a design — reflectivity, angle of incidence and ambient light at your specific installation point all affect real-world range and valid measurement rate more than the datasheet's reference-condition numbers alone will tell you. That's a five-minute check with a sample and a serial terminal, and it catches integration surprises far earlier than discovering them on a production run.
What's next in this line
We've extended this short-range family further for industrial and robotics integrators who need even more coverage below the 2 km mark, down to a 0.05 m minimum range — see Introducing our short-range DToF sensor line for the full new lineup, or send us your ranging requirement directly and we'll match it to the right module today.