First Last / Encoder

Library to read out speed and position from a quadrature encoder. This library uses X2 decoding.

Dependents:   BMT-K9_encoder BMT-K9-Regelaar K9motoraansturing_copy EMGverwerking ... more

encoder.h@3:dcb7bdc73882, 2014-09-29 (annotated)

Committer:
vsluiter
Date:
Mon Sep 29 15:45:09 2014 +0000
Revision:
3:dcb7bdc73882
Parent:
1:2dd7853c911a
Child:
4:69be34f39c9f
Changed to make speed readout optional

Who changed what in which revision?

UserRevisionLine numberNew contents of line
vsluiter 0:c90b36abcbf8 1 #ifndef _ENCODER_H_
vsluiter 0:c90b36abcbf8 2 #define _ENCODER_H_
vsluiter 0:c90b36abcbf8 3
vsluiter 0:c90b36abcbf8 4 #include "mbed.h"
vsluiter 1:2dd7853c911a 5 /** Encoder class.
vsluiter 1:2dd7853c911a 6 * Used to read out incremental position encoder. Decodes position in X2 configuration.
vsluiter 1:2dd7853c911a 7 *
vsluiter 3:dcb7bdc73882 8 * Speed estimation is very crude and computationally intensive. Turned off by default
vsluiter 3:dcb7bdc73882 9 *
vsluiter 1:2dd7853c911a 10 * Example:
vsluiter 1:2dd7853c911a 11 * @code
vsluiter 1:2dd7853c911a 12 * #include "mbed.h"
vsluiter 1:2dd7853c911a 13 * #include "Encoder.h"
vsluiter 1:2dd7853c911a 14 *
vsluiter 3:dcb7bdc73882 15 * Encoder motor1(PTD0,PTC9,true);
vsluiter 1:2dd7853c911a 16 * Serial pc(USBTX,USBRX);
vsluiter 1:2dd7853c911a 17 * pc.baud(115200);
vsluiter 1:2dd7853c911a 18 * while(1) {
vsluiter 1:2dd7853c911a 19 * wait(0.2);
vsluiter 1:2dd7853c911a 20 * pc.printf("pos: %d, speed %f \r\n",motor1.getPosition(), motor1.getSpeed());
vsluiter 1:2dd7853c911a 21 * }
vsluiter 1:2dd7853c911a 22 * @endcode
vsluiter 1:2dd7853c911a 23 */
vsluiter 0:c90b36abcbf8 24 class Encoder
vsluiter 0:c90b36abcbf8 25 {
vsluiter 0:c90b36abcbf8 26 public:
vsluiter 1:2dd7853c911a 27 /** Create Encoder instance
vsluiter 1:2dd7853c911a 28 @param int_a Pin to be used as InterruptIn! Be careful, as not all pins on all platforms may be used as InterruptIn.
vsluiter 1:2dd7853c911a 29 @param int_b second encoder pin, used as DigitalIn. Can be any DigitalIn pin, not necessarily on InterruptIn location
vsluiter 1:2dd7853c911a 30 */
vsluiter 3:dcb7bdc73882 31 Encoder(PinName int_a, PinName int_b, bool speed=false);
vsluiter 1:2dd7853c911a 32 /** Request position
vsluiter 1:2dd7853c911a 33 @returns current position in encoder counts
vsluiter 1:2dd7853c911a 34 */
vsluiter 0:c90b36abcbf8 35 int32_t getPosition(){return m_position;}
vsluiter 1:2dd7853c911a 36 /** Overwrite position
vsluiter 1:2dd7853c911a 37 @param pos position to be written
vsluiter 1:2dd7853c911a 38 */
vsluiter 0:c90b36abcbf8 39 void setPosition(int32_t pos){m_position = pos;}
vsluiter 1:2dd7853c911a 40 /** Request speed
vsluiter 1:2dd7853c911a 41 @returns current speed
vsluiter 1:2dd7853c911a 42 */
vsluiter 0:c90b36abcbf8 43 float getSpeed(){return m_speed;}
vsluiter 0:c90b36abcbf8 44 private:
vsluiter 0:c90b36abcbf8 45 void encoderFalling(void);
vsluiter 0:c90b36abcbf8 46 void encoderRising(void);
vsluiter 3:dcb7bdc73882 47 bool m_speed_enabled;
vsluiter 0:c90b36abcbf8 48 Timer EncoderTimer;
vsluiter 0:c90b36abcbf8 49 Timeout EncoderTimeout;
vsluiter 0:c90b36abcbf8 50 InterruptIn pin_a;
vsluiter 0:c90b36abcbf8 51 DigitalIn pin_b;
vsluiter 0:c90b36abcbf8 52 int32_t m_position;
vsluiter 0:c90b36abcbf8 53 float m_speed;
vsluiter 0:c90b36abcbf8 54 void timeouthandler(void);
vsluiter 0:c90b36abcbf8 55 bool zero_speed;
vsluiter 0:c90b36abcbf8 56 };
vsluiter 0:c90b36abcbf8 57
vsluiter 0:c90b36abcbf8 58
vsluiter 0:c90b36abcbf8 59 #endif //_ENCODER_H_