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• Function check

  jlbrian7 • 07/23/2016 at 02:08 • 0 comments

  The code for this was written in code composer studio, but as far as the encoder goes, it is the same.

  
  

• Hookup

  jlbrian7 • 07/18/2016 at 13:11 • 0 comments

  AMT312-D Pins	Function	EK-TM4C123GXL Pins	Function	Status
  1	TX_ENC+	J1-3 (PB_0)	RX(1)	Not Yet Tested
  2	RX_ENC+	J1-4 (PB_1)	TX(1)	Not Yet Tested
  4	GND	J2-20 (GND)	GND	Good
  6	5 V	J3-21 (VBUS)	VBUS	Good
  8	B+	J4-32 (PD_7)	B+	Good
  10	A+	J4-33 (PD_6)	A+	Good
  12	Z+	J3-26 (PD_3)	Index	Good

• Code

  jlbrian7 • 07/18/2016 at 13:02 • 1 comment

  The code taken from http://forum.43oh.com/topic/8875-problems-using-qei-with-ek-tm4c123gxl/ is good, and makes testing simple. The post was created because the person was actually using hall effect sensors for feedback, not an encoder.
  

  #include <stdint.h>
  #include <stdbool.h>
  
  #include "inc/hw_gpio.h"
  #include "inc/hw_ints.h"
  #include "inc/hw_memmap.h"
  #include "inc/hw_types.h"
  
  #include "driverlib/gpio.h"
  #define PART_TM4C123GH6PM
  #include "driverlib/pin_map.h"
  #include "driverlib/qei.h"
  #include "driverlib/sysctl.h"
  
  
  void config_QEI()
  {
           
    
          SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
          
          //Unlock GPIOD7
          HWREG(GPIO_PORTD_BASE + GPIO_O_LOCK) = GPIO_LOCK_KEY;
          HWREG(GPIO_PORTD_BASE + GPIO_O_CR) |= 0x80;
          HWREG(GPIO_PORTD_BASE + GPIO_O_AFSEL) &= ~0x80;   
          HWREG(GPIO_PORTD_BASE + GPIO_O_DEN) |= 0x80;
          HWREG(GPIO_PORTD_BASE + GPIO_O_LOCK) = 0;
  
          
          // Enable QEI Peripherals
          SysCtlPeripheralEnable(SYSCTL_PERIPH_QEI0);
          
          //Set Pins to be PHA0 and PHB0
  	GPIOPinConfigure(GPIO_PD6_PHA0); //GPIOPinConfigure(0x00031806);  //0x00031806 =>GPIO_PD6_PHA0
  	GPIOPinConfigure(GPIO_PD7_PHB0); //GPIOPinConfigure(0x00031C06);  // 0x00031C06 => GPIO_PD7_PHB0
          
          //Set GPIO pins for QEI
  	GPIOPinTypeQEI(GPIO_PORTD_BASE, (GPIO_PIN_6 | GPIO_PIN_7));
          
          //HWREG(GPIO_PORTD_BASE + GPIO_O_LOCK) = GPIO_LOCK_M; 
           
          // Configure quadrature encoder, use an arbitrary top limit of 2000 and enable QEI 
  	QEIConfigure(QEI0_BASE,(QEI_CONFIG_CAPTURE_A | QEI_CONFIG_NO_RESET | QEI_CONFIG_QUADRATURE | QEI_CONFIG_NO_SWAP), 2000);
          QEIEnable(QEI0_BASE);
          
          //Set position to a middle value
  	QEIPositionSet(QEI0_BASE, 1000);
  
          //Configure and enable velocity
  	QEIVelocityConfigure(QEI0_BASE, QEI_VELDIV_1, SysCtlClockGet()); // Divide by clock speed to get counts/sec
  	QEIVelocityEnable(QEI0_BASE);
  
  }
  void setup()
  {
    config_QEI();
    Serial.begin(9600);
    Serial.println("Start:");
    Serial.println("--------");
  }
  
  void loop()
  {
    uint32_t velocity, position;
    int32_t rotatingdirection;
    
    position = QEIPositionGet(QEI0_BASE); 
    velocity = QEIVelocityGet(QEI0_BASE);
    rotatingdirection = QEIDirectionGet(QEI0_BASE);
    
    Serial.println(position);
    Serial.println(velocity);
    Serial.println(rotatingdirection);
    Serial.println("--------");
    delay(1000);
    
  }

  Output:

  
  

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