Variation Nigel Webb's. AB encoders, using pullups and diodes for connecting 5V (or higher voltage) encoders.

Dependencies:   mbed

Fork of HardwareQuadratureEncoderABZ by Nigel Webb

Revision:
1:e63be50a9453
Parent:
0:25c34018702c
--- a/main.cpp	Mon Nov 17 19:17:21 2014 +0000
+++ b/main.cpp	Sun Jan 25 23:01:30 2015 +0000
@@ -4,6 +4,7 @@
 // Output on debug port to host PC @ 9600 baud
 // 
 // By Nigel Webb, November 2014
+// Modified by Miguel Sánchez, January 2015
 
 /* Connections
    PA_0 = Encoder A
@@ -11,7 +12,11 @@
    PA_4 = Encoder Z 
 */
 
-InterruptIn ZPulse(PA_4) ; // Setup Interrupt for Z Pulse
+// ZPulse(PA_4) ; // Setup Interrupt for Z Pulse --> no index needed here
+
+DigitalIn A(PA_0);
+DigitalIn B(PA_1);
+
 
 void EncoderInitialise(void) {
     // configure GPIO PA0 & PA1 as inputs for Encoder
@@ -38,16 +43,86 @@
     TIM2->CNT = 0x0000;  //reset the counter before we use it  
 }
 
+
+void EncoderInitialiseTIM3(void) {
+    // configure GPIO PA0 & PA1 aka A0 & A1 as inputs for Encoder
+    // Enable clock for GPIOA
+    __GPIOA_CLK_ENABLE(); //equivalent from hal_rcc.h
+ 
+    //stm32f4xx.h 
+    GPIOA->MODER   |= GPIO_MODER_MODER6_1 | GPIO_MODER_MODER7_1 ;           //PA6 & PA7 as Alternate Function   /*!< GPIO port mode register,               Address offset: 0x00      */
+    GPIOA->OTYPER  |= GPIO_OTYPER_OT_6 | GPIO_OTYPER_OT_7 ;                 //PA6 & PA7 as Inputs               /*!< GPIO port output type register,        Address offset: 0x04      */
+    GPIOA->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR6 | GPIO_OSPEEDER_OSPEEDR7 ;     //Low speed                         /*!< GPIO port output speed register,       Address offset: 0x08      */
+    GPIOA->PUPDR   |= GPIO_PUPDR_PUPDR6_1 | GPIO_PUPDR_PUPDR7_1 ;           //Pull Down                         /*!< GPIO port pull-up/pull-down register,  Address offset: 0x0C      */
+    GPIOA->AFR[0]  |= 0x22000000 ;                                          //AF02 for PA6 & PA7                /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
+    GPIOA->AFR[1]  |= 0x00000000 ;                                          //nibbles here refer to gpio8..15   /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
+   
+    // configure TIM3 as Encoder input
+    // Enable clock for TIM3
+    __TIM3_CLK_ENABLE();
+ 
+    TIM3->CR1   = 0x0001;     // CEN(Counter ENable)='1'     < TIM control register 1
+    TIM3->SMCR  = TIM_ENCODERMODE_TI12;     // SMS='011' (Encoder mode 3)  < TIM slave mode control register
+    TIM3->CCMR1 = 0xF1F1;     // CC1S='01' CC2S='01'         < TIM capture/compare mode register 1
+    TIM3->CCMR2 = 0x0000;     //                             < TIM capture/compare mode register 2
+    TIM3->CCER  = 0x0011;     // CC1P CC2P                   < TIM capture/compare enable register
+    TIM3->PSC   = 0x0000;     // Prescaler = (0+1)           < TIM prescaler
+    TIM3->ARR   = 0xffffffff; // reload at 0xfffffff         < TIM auto-reload register
+  
+    TIM3->CNT = 0x0000;  //reset the counter before we use it  
+}
+ 
+void EncoderInitialiseTIM4(void) {
+    //PB6 PB7 aka D10 MORPHO_PB7
+    // Enable clock for GPIOA
+    __GPIOB_CLK_ENABLE(); //equivalent from hal_rcc.h
+ 
+    //stm32f4xx.h 
+    GPIOB->MODER   |= GPIO_MODER_MODER6_1 | GPIO_MODER_MODER7_1 ;           //PB6 & PB7 as Alternate Function   /*!< GPIO port mode register,               Address offset: 0x00      */
+    GPIOB->OTYPER  |= GPIO_OTYPER_OT_6 | GPIO_OTYPER_OT_7 ;                 //PB6 & PB7 as Inputs               /*!< GPIO port output type register,        Address offset: 0x04      */
+    GPIOB->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR6 | GPIO_OSPEEDER_OSPEEDR7 ;     //Low speed                         /*!< GPIO port output speed register,       Address offset: 0x08      */
+    GPIOB->PUPDR   |= GPIO_PUPDR_PUPDR6_1 | GPIO_PUPDR_PUPDR7_1 ;           //Pull Down                         /*!< GPIO port pull-up/pull-down register,  Address offset: 0x0C      */
+    GPIOB->AFR[0]  |= 0x22000000 ;                                          //AF02 for PB6 & PB7                /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
+    GPIOB->AFR[1]  |= 0x00000000 ;                                          //nibbles here refer to gpio8..15   /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
+   
+    // configure TIM4 as Encoder input
+    // Enable clock for TIM4
+    __TIM4_CLK_ENABLE();
+ 
+    TIM4->CR1   = 0x0001;     // CEN(Counter ENable)='1'     < TIM control register 1
+    TIM4->SMCR  = TIM_ENCODERMODE_TI12;     //               < TIM slave mode control register
+    //TIM_ENCODERMODE_TI1 input 1 edges trigger count
+    //TIM_ENCODERMODE_TI2 input 2 edges trigger count
+    //TIM_ENCODERMODE_TI12 all edges trigger count
+    TIM4->CCMR1 = 0xF1F1;     // CC1S='01' CC2S='01'         < TIM capture/compare mode register 1
+    //0xF nibble sets up filter
+    TIM4->CCMR2 = 0x0000;     //                             < TIM capture/compare mode register 2
+    TIM4->CCER  = TIM_CCER_CC1E | TIM_CCER_CC2E;     //     < TIM capture/compare enable register
+    TIM4->PSC   = 0x0000;     // Prescaler = (0+1)           < TIM prescaler
+    TIM4->ARR   = 0xffff; // reload at 0xfffffff         < TIM auto-reload register
+  
+    TIM4->CNT = 0x0000;  //reset the counter before we use it  
+}
+
+
+
+
+/*
 // Z Pulse routine
 void ZeroEncoderCount() {
     TIM2->CNT=0 ; //reset count to zero
 }
+*/
+
+
 
 int main() {
     EncoderInitialise() ;
     
-    ZPulse.rise(&ZeroEncoderCount) ; //Setup Interrupt for rising edge of Z pulse 
-    ZPulse.mode(PullDown) ; // Set input as pull down
+    //ZPulse.rise(&ZeroEncoderCount) ; //Setup Interrupt for rising edge of Z pulse 
+    //ZPulse.mode(PullDown) ; // Set input as pull down
+     A.mode(PullUp);
+     B.mode(PullUp);
      
     unsigned int EncoderPosition ;