Short answer: seven ERDILRF 905 nm modules expose I²C alongside UART — LRF22VB, LRF50VB, LRF100H, LRF200H, LRF300H, LRF600H and LRF1500H. The VB-series publishes a default 7-bit slave address of 0x52 and a 400 kHz maximum clock. Every other model in the catalogue, including LRF50H and the whole LR-series, is UART only.
Why this question is hard to answer with a search
Search for an I²C laser distance sensor and you get short-range time-of-flight chips — the VL53L0X class of part. Those are genuinely I²C-native, cheap and well documented, and they top out at a couple of metres. Search for a long-range 905 nm rangefinder module and you get UART, almost universally, because serial is what the pulsed DToF module market standardised on.
So the engineer who needs both — tens or hundreds of metres of reach and a two-wire bus because the controller has no spare UART — falls into a gap between two bodies of documentation. This page is the list that gap is missing.
Which ERDILRF modules actually speak I²C
| Specification | LRF22VB | LRF50VB | LRF100H | LRF200H | LRF600H |
|---|---|---|---|---|---|
| Interface | UART / I²C | UART / I²C | UART / I²C | UART / I²C | UART / I²C |
| I²C address published | Yes — 0x52 | Yes — 0x52 | No — on request | No — on request | No — on request |
| Max I²C clock | 400 kHz | 400 kHz | Not published | Not published | Not published |
| Range @ 90% refl. | 0.05–20 m | 0.05–50 m | 0.05–100 m | 0.05–200 m | 0.05–600 m |
| Range @ 10% refl. | 0.05–10 m | 0.05–20 m | 0.05–30 m | 0.05–70 m | 0.05–200 m |
| Distance unit on the wire | mm | mm | cm | cm | cm |
| Supply voltage | 3.0–3.6 V DC | 3.3–5 V DC | 9–36 V DC | 9–36 V DC | 9–36 V DC |
| Weight | 1.5 g | 1.3 g | 20 ± 2 g | 20 ± 2 g | 20 ± 2 g |
| Average power | < 0.2 W | 0.2 W | 0.7 W | 0.7 W | 1.2 W |
LRF300H and LRF1500H also list UART / I²C and share the H-series electrical envelope. Everything else in the catalogue — LRF50H, LRF10VB, LRF1200A1, LRF3000A1, the LR-series and the SPD-series — is UART only, so if I²C is a hard requirement those models are out before you start comparing range.
The VB-series: fully documented I²C
The LRF22VB 20 m module and LRF50VB 50 m module are the two parts where you can write the driver from the manual without asking anyone a question. Both specify an I²C slave interface with a default address of 0x52 in 7-bit address mode, supporting a maximum clock frequency of 400 kHz — Fast-mode in the terms of the NXP I²C-bus specification. Both manuals document a single-register write sequence for configuration.
They are also the two lightest parts in the range, at 1.5 g and 1.3 g, and the only ones that run on logic-level supplies of 3.0–3.6 V and 3.3–5 V respectively. That combination — two wires, a few grams, no separate 9–36 V rail — is why they end up in small robots, AGV bumpers and camera focus assemblies rather than in cabinets.
The H-series: I²C is listed, the address is not
Here is the part most vendors would leave vague. The LRF100H, LRF200H, LRF300H, LRF600H and LRF1500H all list UART / I²C as their interface, and we have no reason to doubt it — but the I²C slave address and register map are not stated anywhere in those five manuals. That is a known, logged gap in our documentation, not something we are going to paper over by assuming the VB-series 0x52 carries across. It may well be 0x52. We have not confirmed it, so we are not publishing it as if we had.
The practical consequence: if you are designing an H-series module onto an I²C bus, ask us for the register map in writing before you commit the schematic. If your schedule cannot absorb that round trip, design the UART path first and treat I²C as an optimisation.
The 10× trap: mm on VB, cm on H
This one has bitten real integrations, so it is worth stating plainly. Across both interfaces, the VB-series reports distance in millimetres and the H-series reports distance in centimetres. A two-byte little-endian value of 0x1102 means 4354 mm on an LRF22VB and 4354 cm on an LRF100H. Same frame layout, same header byte, same checksum rule — and a factor of ten between the two answers.
The out-of-range sentinel differs the same way: LRF22VB returns 20000, LRF50VB returns 50000, and the H-series modules return 65535, each in their own unit. Never port a driver from one family to the other by changing only the model name in a comment. Our serial protocol and checksum guide walks through the frame structure both families share.
When UART is still the better answer
I²C is attractive because it is two wires and because you may already have a bus. It is worth being honest about where it stops being the right choice:
- Cable length. I²C was specified for on-board communication and its total bus capacitance budget is what limits it. A sensor on a silo roof twenty metres from the controller is a UART job, or an RS-485 job, not an I²C job.
- Throughput at high update rates. The H-series modules default to 1 kHz output. Polling a 1 kHz sensor over a shared 400 kHz bus that also carries an IMU and an EEPROM needs a real timing budget, whereas the 460800 baud UART stream is a dedicated pipe that simply arrives.
- Address collisions. Two sensors of the same model on one bus need distinct addresses. With the VB-series both default to 0x52, so a two-sensor design needs either address reconfiguration or a bus multiplexer.
If you land on UART, our UART-TTL integration guide covers wiring and logic levels. All modules discussed here are Class 1 under IEC 60825-1.
Frequently asked questions
What is the I²C address of an ERDILRF laser rangefinder module?
For the LRF22VB and LRF50VB it is 0x52 by default, in 7-bit address mode. For the H-series modules the address is not published in the manual; contact us for the register map rather than assuming the VB-series value applies.
What I²C clock speed do these modules support?
The LRF22VB and LRF50VB both specify a maximum clock of 400 kHz, which is standard Fast-mode. The H-series maximum clock is not published.
Can I get a 200 m laser rangefinder module with an I²C output?
Yes — the LRF200H lists UART and I²C and is rated 0.05–200 m at 90% reflectivity, or 0.05–70 m at 10%. Request the I²C register map before you design it in, since it is not in the published manual.
Does the LRF50H support I²C?
No. Despite sitting in the same H-series naming scheme, the LRF50H is UART only. The LRF100H and above are the H-series parts that list I²C.
Why does my distance reading look ten times wrong?
Almost certainly a unit mismatch. VB-series modules report millimetres, H-series modules report centimetres, and the frame format is otherwise identical, so a driver written for one family returns a plausible-looking but ten-times-off value on the other.
Ask for the register map
Tell us the model you are evaluating, your bus topology and how many sensors share it, and we will send the interface documentation you need — including whether an I²C design is realistic for your cable run. Reach us through our contact page.