File content as of revision 0:0532a6e10a23:

#ifndef _HALLSENSOR_HARDWARE_DECODER_H
#define _HALLSENSOR_HARDWARE_DECODER_H



#include "mbed.h"

// Hardware Quadrature Encoder ABZ for Nucleo F401RE
// Output on debug port to host PC @ 9600 baud


/* Connections
   PA_0 = Encoder A
   PA_1 = Encoder B
   PA_4 = Encoder Z
*/

InterruptIn ZPulse(PA_4) ; // Setup Interrupt for Z Pulse


void EncoderInitialise(void)
{
    // configure GPIO PA0 & PA1 as inputs for Encoder
    RCC->AHB1ENR |= 0x00000001;  // Enable clock for GPIOA

    GPIOA->MODER   |= 0x0000000A;//GPIO_MODER_MODER0_1 | GPIO_MODER_MODER1_1 ;           //PA0 & PA1 as Alternate Function   /*!< GPIO port mode register,               Address offset: 0x00      */
    GPIOA->OTYPER  |= 0x00000003;//GPIO_OTYPER_OT_0 | GPIO_OTYPER_OT_1 ;                 //PA0 & PA1 as Inputs               /*!< GPIO port output type register,        Address offset: 0x04      */
    GPIOA->OSPEEDR |= 0x0000000F;//high speed //GPIO_OSPEEDER_OSPEEDR0 | GPIO_OSPEEDER_OSPEEDR1 ;     // Low speed                        /*!< GPIO port output speed register,       Address offset: 0x08      */
    GPIOA->PUPDR   |= 0x00000005;//pull high  //GPIO_PUPDR_PUPDR0_1 | GPIO_PUPDR_PUPDR1_1 ;           // Pull Down                        /*!< GPIO port pull-up/pull-down register,  Address offset: 0x0C      */
    GPIOA->AFR[0]  |= 0x00000011 ;                                          //  AF01 for PA0 & PA1              /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
    GPIOA->AFR[1]  |= 0x00000000 ;                                          //                                  /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */

    // configure TIM2 as Encoder input
    RCC->APB1ENR |= 0x00000001;  // Enable clock for TIM2

    TIM2->CR1   = 0x0001;     // CEN(Counter ENable)='1'     < TIM control register 1
    TIM2->SMCR  = 0x0003;     // SMS='011' (Encoder mode 3)  < TIM slave mode control register
    TIM2->CCMR1 = 0xF1F1;     // CC1S='01' CC2S='01'         < TIM capture/compare mode register 1
    TIM2->CCMR2 = 0x0000;     //                             < TIM capture/compare mode register 2
    TIM2->CCER  = 0x0011;     // CC1P CC2P                   < TIM capture/compare enable register
    TIM2->PSC   = 0x0000;     // Prescaler = (0+1)           < TIM prescaler
    TIM2->ARR   = 0xffffffff; // reload at 0xfffffff         < TIM auto-reload register

    TIM2->CNT = 0x0000;  //reset the counter before we use it
}

void EncoderInitialise_HAL(void)
{

    
    // init structure
    TIM_HandleTypeDef       htim2;
    TIM_Encoder_InitTypeDef sConfig;
    TIM_MasterConfigTypeDef sMasterConfig;
    GPIO_InitTypeDef        GPIO_InitStruct;
    // timer GPIO setup
    __HAL_RCC_GPIOA_CLK_ENABLE();
    GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1;//pin num PA "0"
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF1_TIM2; //timer
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct); //port P"A"0
    // basic timer setup
    __HAL_RCC_TIM2_CLK_ENABLE();
    htim2.Instance = TIM2; //timer
    htim2.Init.Prescaler = 0;
    htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
    htim2.Init.Period = 0x000fffff;
    htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
    //encoder mode setup
    sConfig.EncoderMode = TIM_ENCODERMODE_TI12;
    sConfig.IC1Polarity = TIM_ICPOLARITY_FALLING;
    sConfig.IC1Selection = TIM_ICSELECTION_DIRECTTI;
    sConfig.IC1Prescaler = TIM_ICPSC_DIV1;
    sConfig.IC1Filter = 2;
    sConfig.IC2Polarity = TIM_ICPOLARITY_RISING;
    sConfig.IC2Selection = TIM_ICSELECTION_DIRECTTI;
    sConfig.IC2Prescaler = TIM_ICPSC_DIV1;
    sConfig.IC2Filter = 2;
    HAL_TIM_Encoder_Init(&htim2, &sConfig);
    // timer mode setup
    sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
    sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
    HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig);
    // timer start
    HAL_TIM_Encoder_Start(&htim2, TIM_CHANNEL_ALL);

}

// Z Pulse routine
void ZeroEncoderCount()
{
    TIM2->CNT=0 ; //reset count to zero
}


#endif