SmallRobots' Tiny AS5048A Encoder Tracks a Magnet for Easy 0.022°-Resolution Angle Sensing

Austria-based SmallRobots has launched a compact encoder board based on the AMS AS5048A sensor — designed to measure the absolute angle of a nearby magnet with a resolution of 0.022°.

"Ideal for small robots and motor control applications, this small sensor board measures the orientation of a nearby magnet (contactless measurement)," SmallRobots explains of its creation. "It uses an SPI interface for communications, and can return angle values to 14bit precision — that’s 16384 counts per revolution, or 0.022° degrees. It's tiny 21×17mm (around 0.83×0.67") dimensions mean it will fit any project, and can be easily mounted even to tiny motors or actuators using the 2.2mm (around 0.087") holes."

"Existing magnetic encoder PCBs I could find to buy always seemed to have one or more of the following shortcomings — they were too large, had inconvenient bits sticking out of them, were super-expensive, required soldering wires to them, didn't offer the SPI interface or had poor accuracy/performance," SmallRobots notes. "This meant they didn't work in my small robot designs, or at least not in the way I wanted them to. So I decided to design my own encoder board, with none of those problems."

Designed to work with 3.3V or 5V power, the compact sensor board tracks the rotation of a diametrically magnetized magnet - one of which is included as part of the bundle. The board connects to an SPI bus via a SH-1mm six-pin connector. "One cable is included," SmallRobots notes, "and pre-made cables are inexpensive and easily available should you require more."

A driver is provided for use with Arduino microcontrollers, while support is baked in to the SimpleFOC library — designed to offer simplified Field Oriented Control (FOC) in Arduino projects.

The board is now available on SmallRobots' Tindie store at $15, which includes a single sensor PCB, bundled cable, and a small magnet.