Quadrature Encoder Drivers

NuttX supports a low-level, two-part Quadrature Encoder driver.

1. An “upper half”, generic driver that provides the common Quadrature Encoder interface to application level code, and

2. A “lower half”, platform-specific driver that implements the low-level timer controls to implement the Quadrature Encoder functionality.

Files supporting the Quadrature Encoder can be found in the following locations:

• Interface Definition. The header file for the NuttX Quadrature Encoder driver reside at include/nuttx/sensors/qencoder.h. This header file includes both the application level interface to the Quadrature Encoder driver as well as the interface between the “upper half” and “lower half” drivers. The Quadrature Encoder module uses a standard character driver framework.

• “Upper Half” Driver. The generic, “upper half” Quadrature Encoder driver resides at drivers/sensors/qencoder.c.

• “Lower Half” Drivers. Platform-specific Quadrature Encoder drivers reside in arch/<architecture>/src/<hardware> directory for the specific processor <architecture> and for the specific <chip> Quadrature Encoder peripheral devices.