SPD1200N0 Mini 905nm Laser Rangefinder Module for Thermal Imagers, Night Vision and Civil Optics

Technical Specifications

Functional Description

The system supports single measurement and continuous measurement functions.

3.1 Baud Rate Configuration
Allows modification of the serial communication baud rate.

3.2 Single Measurement
Triggers a single distance measurement to the target. For low-reflectivity targets, the system automatically repeats measurements until stable distance data is obtained. The final result is transmitted via the serial interface in the standard data format.

3.3 Continuous Measurement
In continuous measurement mode, the laser module performs repeated distance measurements on the target. The typical refresh rate can be set to 2 Hz, and the maximum refresh rate can reach 15 Hz.

Electrical Interface Definition

Mechanical Interface

Product Description

The SPD1200N0 is a miniature 905nm laser rangefinder module developed for civil electro-optical products that need stable distance measurement in an extremely small package. It is intended for integration into thermal imagers, night vision devices, telescopes, laser illuminators and lightweight civil UAV or outdoor observation equipment, where low size, low mass and simple UART-TTL integration are more valuable than oversized long-range hardware.

The module operates at 905nm ±5nm and measures from 0.2m to 1200m, with a maximum nighttime range up to 1500m under favorable conditions. Ranging accuracy is specified as ±0.3m below 100m, and ±0.3m + d×0.7‰ from 100m to 1200m, where d is the measured distance. The valid measurement rate is ≥98%, false alarm rate is ≤1%, beam divergence is <4.5mrad, and the receiving aperture is Ø6.5mm. These figures place the SPD1200N0 in the compact 905nm OEM rangefinder class commonly used in handheld optics and thermal-imaging integration. 

Unlike bulkier 1km-class modules, the SPD1200N0 emphasizes a small cylindrical body and low SWaP profile. It supports single measurement and continuous measurement, with a measuring frequency of 2–15Hz or 4–15Hz Adaptive. In single mode, when target reflectivity is low, the module automatically repeats internal measurements until stable distance data is obtained before sending the final result, which improves usability in real outdoor conditions rather than only on clean white targets in tidy demo rooms.

Electrically, the module uses a UART-TTL communication interface with a default baud rate of 115200bps and a supply voltage of 3.3V to 5V. Startup time is ≤200ms, average operating power is approximately 0.45W, and maximum power is ≤0.75W. That makes it practical for battery-powered optics, compact sensor heads and light civil UAV payloads where power margin is always annoyingly finite.

The communication protocol is designed for easy secondary development. It uses an 8-byte frame with 0x55 0xAA headers, function code, four data bytes and checksum. Supported functions include single-shot ranging, continuous ranging, stop ranging, optional angle measurement for angle-sensor versions, power-on self-test, baud-rate configuration and LD constant-ON mode for development. Distance data is returned in hexadecimal as the actual value multiplied by 10, so the host reconstructs the range with one decimal place. Baud-rate changes take effect only after reboot, and the manual explicitly warns not to keep LD constant-ON mode enabled for long periods.

Mechanically, the SPD1200N0 is especially compact at Ø15.7 × 21.3mm and weighs about 5g. It uses a 6-pin interface providing SW-SHOT, RXD, TXD, reserved I/O, VCC and GND. The guide notes that the Enable pin must be pulled LOW (connected to GND) during operation. This extremely short cylindrical format is well suited to small observation tubes, compact thermal viewer housings and embedded optics where available depth is limited.

The environmental envelope is practical for civil outdoor products: −20°C to +60°C operating temperature, −30°C to +70°C storage, IP67 protection inside the lens cavity, 1000g/ms shock resistance along the optical axis, 5–50–5Hz, 2.5g vibration resistance, and MTBF ≥1500h. These values are a good match for outdoor observation devices, smart field equipment and portable electro-optical products.

For optical-window integration, the manual recommends H-K9L optical glass or fused silica, wedge-angle tolerance ≤3′, surface roughness around Ra 0.012, and an AR coating optimized for 855–955nm with transmittance ≥99.5%. After hydrophobic or hard coatings, total transmittance should remain ≥98%. The recommended window thickness is 2–4mm, with the transmit optical axis parallel to the window normal and the air gap below 0.5mm to minimize additional loss and back-reflection. Tiny module, same unforgiving optics physics.

The use notes also clarify realistic field performance. Under the reference condition—a medium-reflectivity target such as a building wall, perpendicular incidence, clear weather and no direct sunlight—the module achieves nominal performance. The manual also notes that high-reflectivity targets such as highway traffic signs can reach farther distances, while low-reflectivity targets such as trees or animals range shorter. Rain, fog, snow and haze will reduce usable range, and tripod mounting is recommended for long-distance measurement.

Search behavior around this class of module usually combines wavelength + form factor + application, such as “905nm laser rangefinder module,” “night vision rangefinder module,” or “thermal imaging laser ranging module.” Similar OEM pages also position 905nm modules around night vision, thermal imaging and compact civil optics integration, which aligns well with SPD1200N0’s niche.

Overall, the SPD1200N0 is best understood as a micro 905nm ranging core for civil electro-optical integration: small enough for tight optical assemblies, strong enough for 1200m-class daytime and 1500m-class nighttime performance, and simple enough for UART-based secondary development in thermal imaging, night vision, telescopic observation and lightweight civil payloads.