AS5048A SPI - Magnetic rotary encoder library
Library for communication over the SPI interface with the ams.com AS5048A magnetic rotary encoder.
Example:
Simple readout of a single angle measurement from a single sensor on the SPI-bus
#include "mbed.h" #include <as5048spi.h> // The sensors connection are attached to pins 5-8 As5048Spi sensor(p5, p6, p7, p8); Serial pc(USBTX, USBRX); // tx, rx int main() { while(1) { // const int* angles = sensor.read_angle(); int angle = angles[0]; // The read angle returns the value returned over the SPI bus, including parity bit pc.printf("Read result: %x\r\n", angle); if( As5048Spi::parity_check(angle) ) { // Convert range from 0 to 2^14-1 to 0 - 360 degrees int degrees = As5048Spi::degrees(angle)/100; pc.printf("Parity check succesfull.\r\n"); pc.printf("Angle: %i degrees\r\n", degrees ); } else { pc.printf("Parity check failed.\r\n"); } wait_ms(500); } }
The class supports daisy chaining multiple sensors on the SPI-bus as well. See: SPI-Daisy-Chaining.
Diff: as5048spi.h
- Revision:
- 4:06b89a41109e
- Parent:
- 3:a8ad32e439d4
diff -r a8ad32e439d4 -r 06b89a41109e as5048spi.h --- a/as5048spi.h Tue Mar 17 14:46:45 2015 +0000 +++ b/as5048spi.h Tue Mar 17 14:56:30 2015 +0000 @@ -21,7 +21,7 @@ } As5048Diagnostics; - +//! Class for interfacing with the AMS AS5048A magnetic rotary sensor over the SPI-interface. class As5048Spi { public: @@ -46,7 +46,6 @@ /// Performs a single angle measurement on all sensors /// @return Array of raw angle data. To get the 14-bit value representing /// the angle, apply the mask() to the result. - /// To get an angle in degrees divide 360 by the result of the call to mask(). const int* read_angle(); /// Performs sequential angle measurements on all sensors. The first time this @@ -54,7 +53,6 @@ /// will be returned by the next call to this method. /// @return Array of raw angle data. To get the 14-bit value representing /// the angle, apply the mask() to the result. - /// To get an angle in degrees divide 360 by the result of the call to mask(). const int* read_angle_sequential(); /// Returns lowest 14-bits @@ -62,6 +60,7 @@ /// Applies the mask to the first n bytes in the read buffer (for daisychained sensors). static void mask(int* sensor_results, int n); + /// Checks if the return value from the sensor has the right parity /// @return true if ok static bool parity_check(int sensor_result);