The 2m LiDAR Is Not a Cheaper TFS20-L
Quick Answer
The Benewake TFS20-L is our pick for a small drone rangefinder: it reaches 20m in favourable conditions, tolerates bright outdoor light and has documented ArduPilot support. The TF-LC02 is a 3cm–2m, indoor-biased proximity sensor for microcontroller projects. Similar dimensions do not make them interchangeable.
Why the Headline Range Changes the Job
We added the Benewake TFS20-L and Benewake TF-LC02 to the same sensor range, but we would not shortlist them for the same aircraft. Both are single-point Time-of-Flight modules: each reports one distance along a narrow optical path rather than drawing the 360-degree map produced by a scanning LiDAR.
The TFS20-L measures from 0.2m to 20m against a 90% reflective target in low ambient light. Benewake specifies 15m at 100 klux, and just 9m against a 10% reflective target under the same bright-light condition. That qualification matters more than the 20m headline: grass, dark surfaces, sunlight and vehicle attitude can all shorten usable range.
The TF-LC02 measures 3cm to 200cm against a 90% reflective indoor target. Its datasheet explicitly warns that direct sunlight degrades performance. That makes it useful for short-range presence sensing, robot clearance or an indoor landing experiment; it is not the budget version of a 20m outdoor altimeter.
The Numbers We Would Design Around
| Specification | TFS20-L | TF-LC02 |
|---|---|---|
| Rated range | 0.2–20m at 90% reflectivity, low ambient light | 0.03–2m at 90% reflectivity, indoors |
| Accuracy | ±6cm to 6m; 1% beyond 6m | ±2cm to 1m; ±5% from 1–2m |
| Frame timing | 20, 50, 100 or 250Hz | 33ms acquisition time, about 30Hz |
| Interface | 3.3V UART or I²C | 3.3V UART |
| Module size | 21 × 15 × 7.87mm | 20 × 11.5 × 7.6mm |
| Protection | No enclosure or IP rating | Bare consumer module; indoor use recommended |
There is also a catalogue trap worth recording. Our Shopify variant fields currently say 5g for the TFS20-L and 15,000g for the TF-LC02; neither is a trustworthy module mass. Benewake specifies the TFS20-L itself at 1.35g and describes the TF-LC02 as under 1g. For an aircraft mass budget, use the manufacturer module figure, then weigh your finished cable and mount.
What We Would Actually Fit
For ArduPilot altitude hold or terrain following, we would fit the TFS20-L. ArduPilot's current Benewake documentation lists it as a supported serial rangefinder using a spare UART, 115200 baud and the Benewake TF03 driver type. Power it from a proper 3.3V rail: this is not a 5V-tolerant accessory, and the bare board still needs vibration, moisture and debris protection.
Choose the TF-LC02 only when the real task ends inside 2m and the host can parse its UART protocol. It is absent from ArduPilot's supported Benewake list, so do not assume the TFS20-L setup transfers across. If you need a room map rather than one distance, read our LD19 versus TFmini-S explanation. For drift control rather than height alone, our optical-flow sensor guide explains why range and horizontal motion are separate measurements.
FAQ
Q: Can the TF-LC02 replace the TFS20-L on an outdoor drone?
A: No. Its specified range stops at 2m and Benewake warns that direct sunlight degrades performance. Use it for controlled short-range experiments, not as a 20m outdoor altimeter.
Q: Does the TFS20-L see obstacles around the aircraft?
A: No. Its field of view is under 2 degrees, so it returns one narrow distance. Multiple sensors or a scanning LiDAR are needed for broader obstacle coverage.
Q: Is either sensor weatherproof?
A: No IP rating is stated for the TFS20-L, and the TF-LC02 is an exposed indoor-oriented module. The host installation must keep the optical path clean and protect the electronics without obstructing the lens.