SPD1200M2 Micro 905nm Distance Engine for Thermal Imaging, Night Vision and Civil UAVs

Technical Specifications

Functional Description

The system supports single measurement and continuous measurement functions.

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

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 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 SPD1200M2 is an ultra-compact 905nm laser rangefinder module developed for OEM integration in night vision devices, thermal imagers, telescopes, laser illuminators and lightweight civil UAV payloads. Compared with heavier 1km-class cylindrical modules, it is built around an ultra-slim rectangular format and a low-power UART-TTL interface, making it better suited to tightly packed electro-optical assemblies and miniature payload compartments.

The module operates at 905nm ±5nm and supports a measuring range of 0.2m to 1200m, with a maximum nighttime range up to 1500m. The specification states that strong sunlight and poor visibility can reduce effective range, which is normal for compact 905nm rangefinders. Ranging accuracy is ±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%, the false alarm rate is ≤1%, beam divergence is <4mrad, and the receiving aperture is 5.0mm × 7mm. Those figures position the SPD1200M2 as a miniature 905nm ranging core optimized for electro-optical integration rather than long-range industrial standoff use.

One of its strongest selling points is the 2–15Hz measuring frequency, with the manual also noting 4–15Hz adaptive operation as an option. The module supports both single measurement and continuous measurement. In single mode, when the target reflectivity is low, the system automatically repeats internal measurements until stable data is obtained, then sends the final result over the serial interface. In continuous mode, the typical refresh rate can be set to 2Hz, while the maximum reaches 15Hz. This gives designers more flexibility than the usual “slow single-shot only” 905nm module class.

Electrically, the SPD1200M2 uses a UART-TTL communication interface with a default baud rate of 115200bps, running from 3.3V to 5V. Startup time is ≤200ms, startup inrush current is about 380mA, average operating power is about 0.45W, and maximum power is ≤0.75W. That SWaP profile makes it attractive for battery-powered optics, compact sensor heads and small airborne payloads where every gram and watt gets audited like a suspicious expense report.

The protocol is intentionally simple. The sensor uses an 8-byte frame with 0x55 0xAA header bytes, a function code, four data bytes and checksum. Supported functions include single-shot ranging, continuous ranging, stop ranging, optional angle measurement for versions fitted with an angle sensor, power-on self-test, baud-rate configuration and LD constant-ON mode for development. The baud-rate menu supports 9600, 14400, 19200, 38400, 56000, 57600, 115200 and 230400bps, with changes taking effect after reboot. Distance data is returned in hexadecimal as the actual value multiplied by 10, so the host can reconstruct the range with one decimal place. The manual also warns not to keep LD constant-ON mode enabled for long periods.

Mechanically, the SPD1200M2 is very small at 7.7mm × 15.3mm × 27.85mm and weighs ≤6g. It uses a 6-pin electrical interface with SW-SHOT, RXD, TXD, reserved I/O, VCC and GND. The manual notes that the Enable pin must be pulled LOW (connected to GND) during operation, which is one of those tiny details that saves a lot of muttering during bring-up. Because the body is slim and rectangular, it is easier to place inside narrow optical channels and compact housings than many older cylindrical 905nm modules.

The environmental envelope is practical for civil outdoor electronics: −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 characteristics fit portable optics, embedded electro-optical heads and compact payloads used in outdoor monitoring and field instruments.

For front-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 optimised for 855–955nm with transmittance ≥99.5%. After any hydrophobic or hard coatings, total transmittance should remain ≥98%. The guide also recommends keeping the optical-window thickness around 2–4mm, aligning the transmit optical axis parallel to the window normal, and keeping the air gap below 0.5mm to reduce extra loss and back-reflection. This is the sort of detail that quietly determines whether the shipped product behaves like the datasheet or like a small optical tragedy.

The use notes also make the real-world behaviour clear. 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 further notes representative target behaviour: high-reflectivity targets such as highway traffic signs, medium-reflectivity building walls, and low-reflectivity targets such as trees or animals all produce different maximum ranges, while rain, fog, snow and haze reduce usable distance. For long-distance measurement, tripod mounting is recommended.

Taken together, the SPD1200M2 is best understood as a micro 905nm ranging core for civil electro-optical integration: tiny enough for miniature optics, strong enough for 1200m-class daytime and 1500m-class nighttime performance, and simple enough for quick UART-based secondary development in night vision, thermal imaging, portable observation devices, civil UAV payloads and smart field equipment. Similar market offerings in the 905nm segment are also commonly framed around night vision, thermal imaging and UAV integration, which lines up neatly with this module’s actual niche.