The easiest way to get a contactless encoder with high reliability and durability is by using the AS5601 along with with a diametrically magnetized magnet as shown in the illustration on this slide. The AS5601, like all ams OSRAM position sensors, uses ams OSRAM's proven angle measuring principle and is therefore robust against stray magnetic fields, temperature variation, and displacement. The absolute 12-bit angle information can be read over I2C or as incremental output signals. Resolution of the incremental quadrature output can be configured to the resolution of a mechanical grid. This can be done using the I2C interface and does not require a special programmer.