Timer as Encoder

Added support to use HardwareTimer as an encoder input

STM32F1/cores/maple/HardwareTimer.cpp

@@ -142,6 +142,28 @@ void HardwareTimer::refresh(void) {
     timer_generate_update(this->dev);
 }
 
+/*  CARLOS Changes to add encoder mode.*/
+
+//direction of movement. (to be better described). 
+    uint8 HardwareTimer::getDirection(){
+        return get_direction(this->dev);
+    }
+    
+//set if the encoder will count edges on one, which or both channels. 
+    void HardwareTimer::setEdgeCounting(uint32 counting) {
+        (dev->regs).gen->SMCR = counting;//TIMER_SMCR_SMS_ENCODER3; //choose encoder 3, counting on 
+    
+    }
+    
+    uint8 HardwareTimer::getEdgeCounting() {
+        return (dev->regs).gen->SMCR;
+    }
+    
+    
+
+//set the polarity of counting... not sure how interesting this is.. 
+    void HardwareTimer::setPolarity(){} 
+
 /* -- Deprecated predefined instances -------------------------------------- */
 
 HardwareTimer Timer1(1);

STM32F1/cores/maple/HardwareTimer.h

@@ -38,6 +38,10 @@
 /** Timer mode. */
 typedef timer_mode TimerMode;
 
+//CARLOS
+//defines for the ENCODER mode.
+
+
 /**
  * @brief Interface to one of the 16-bit timer peripherals.
  */
@@ -205,6 +209,23 @@ public:
      */
     void refresh(void);
 
+//CARLOS.
+/*
+    added these functions to make sense for the encoder mode. 
+*/
+//direction of movement. (to be better described). 
+    uint8 getDirection();
+    
+//set if the encoder will count edges on one, which or both channels. 
+    void setEdgeCounting(uint32 counting);
+    uint8 getEdgeCounting(); //not sure if needed. 
+
+//set the polarity of counting... not sure how interesting this is.. 
+    void setPolarity();
+    
+//add the filtering definition for the input channel.
+    
+
     /* Escape hatch */
 
     /**

STM32F1/cores/maple/libmaple/timer.c

@@ -38,6 +38,8 @@
 static void disable_channel(timer_dev *dev, uint8 channel);
 static void pwm_mode(timer_dev *dev, uint8 channel);
 static void output_compare_mode(timer_dev *dev, uint8 channel);
+static void encoder_mode(timer_dev *dev, uint8 channel) ;//CARLOS
+
 
 static inline void enable_irq(timer_dev *dev, timer_interrupt_id iid);
 
@@ -230,6 +232,10 @@ void timer_set_mode(timer_dev *dev, uint8 channel, timer_mode mode) {
     case TIMER_OUTPUT_COMPARE:
         output_compare_mode(dev, channel);
         break;
+    //added by CARLOS. 
+    case TIMER_ENCODER: 
+        encoder_mode(dev, channel); //find a way to pass all the needed stuff on the 8bit var
+        break;
     }
 }
 
@@ -293,6 +299,13 @@ void timer_detach_interrupt(timer_dev *dev, uint8 interrupt) {
     dev->handlers[interrupt] = NULL;
 }
 
+//CARLOS 
+uint8 get_direction(timer_dev *dev){
+    return *bb_perip(&(dev->regs).gen->CR1, TIMER_CR1_DIR_BIT);
+}
+
+
+
 /*
  * Utilities
  */
@@ -313,6 +326,31 @@ static void output_compare_mode(timer_dev *dev, uint8 channel) {
     timer_cc_enable(dev, channel);
 }
 
+//added by CARLOS.
+static void encoder_mode(timer_dev *dev, uint8 channel) {
+    
+    //prescaler. 
+    //(dev->regs).gen->PSC = 1;
+
+    //map inputs. 
+    (dev->regs).gen->CCMR1 = TIMER_CCMR1_CC1S_INPUT_TI1 | TIMER_CCMR1_CC2S_INPUT_TI2 | TIMER_CCMR1_IC2F | TIMER_CCMR1_IC1F ;
+
+    (dev->regs).gen->SMCR = TIMER_SMCR_SMS_ENCODER3; //choose encoder 3, counting on both edges. 
+
+    //polarity
+    //(dev->regs).gen->CCER = TIMER_CCER_CC1P; //to invert the counting, only one of the inputs should be inverted.  
+
+    //set the interval used by the encoder.
+    //timer_set_reload(dev, 1000);
+
+//    (dev->regs).gen->CR1  |=TIMER_CR1_UDIS_BIT;
+
+    //run timer
+    timer_resume(dev);
+}
+
+
+
 static void enable_adv_irq(timer_dev *dev, timer_interrupt_id id);
 static void enable_bas_gen_irq(timer_dev *dev);
 

STM32F1/system/libmaple/include/libmaple/timer.h

@@ -569,6 +569,8 @@ typedef enum timer_mode {
     /* TIMER_ONE_PULSE, TODO: In this mode, the timer can generate a single
      *                        pulse on a GPIO pin for a specified amount of
      *                        time. */
+     
+     TIMER_ENCODER,  //CARLOS Change
 } timer_mode;
 
 /** Timer channel numbers */
@@ -620,6 +622,11 @@ void timer_attach_interrupt(timer_dev *dev,
                             voidFuncPtr handler);
 void timer_detach_interrupt(timer_dev *dev, uint8 interrupt);
 
+//CARLOS 
+uint8 get_direction(timer_dev *dev);
+
+
+
 /**
  * Initialize all timer devices on the chip.
  */