PAT9125EL - Miniature Optical Navigation for Surface Tracking

The PAT9125EL is a miniature low power optical navigation chip using PixArt’s LASER-based optical navigation technology enabling digital surface tracking.

Hello World

Import programPAT9125_OTS_L476RG_Program

Initial Release of Program for PAT9125 OTS on L476RG Platform


Import librarypat9125_mbed

Library for PAT9125 on L476RG platform




The PAT9125EL integrates an ultra-low power CMOS-processed optical navigation chip with a LASER light source in a single miniature package, providing wide depth of field (DOF) range on glossy surfaces, and design flexibility into highly space constraint devices. This tracking system also does not require code wheel, code strip and any special marking on tracking surface for motion control or tracking purposes.

PAT9125EL is based upon PixArt’s optical navigation technology of LASER which measures changes in position by optically acquiring sequential surface images (frames) and mathematically determining the speed, the direction and the magnitude of motion. The displacement X and Y information are available in registers. A host controller can read and translate the displacement X and Y information from the SPI (PAT9125EL-TKMT) or I2C (PAT9125EL-TKIT) serial interface.

Tracking Configurations that PAT9125EL supports:

* Tracking on a moving surface:


* Tracking on the side of the rotational shaft:


* Tracking on end of the rotational shaft:


* Tracking on disk edge:


* Tracking on rotational bezel:


For more information on how to setup and run the PAT9125EL with ST NUCLEO-L476RG, please also visit the Wiki Page:

In addition, we have also tested it on Nordic, NXP/Freescale Platforms. Please see Tested Platforms for more compatible platforms. Do not see your platform of choice? Please let us know.

Part Number


Where to Buy

North America:

WPG America (Distributor)


Taiwan and China:

AIT Group (Distributor)


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