TM4C123GH6PGE: Question QEI of DK-TM4C123G

Hello

Same problem. ? 

thanks

Hello Amit,

i'm think  by define 32bit  full   maxposition  of  "0xFFFF.FFFF"   !!

Question : What does Maxposition mean &  How  value should I set ?

I just checked the hardware.

Waveform is a problem as you have told me.

I just checked the software

[ Direction CCW ]  CH1 : A1 , CH2 : B1

.[ Log Message]

[ Direction CW ]  CH1 : A1 , CH2 : B1

.[ Log Message]

[ Source Code Modify ]

Addtion  

     (note) QEIVelocityConfigure(uint32_t ui32Base, uint32_t ui32PreDiv,  uint32_t ui32Period)

1. QEIVelocityConfigure(QEI1_BASE, QEI_VELDIV_2, SysCtlClockGet());    

                  SysCtlClockGet()/50  - ->  SysCtlClockGet()

                    40Mhz/50 = 800Khz  -->    40Mhz  !!

2. Delay. ( SysCtlDelay(SysCtlClockGet()/24);)

Queistion :   What is mean about  given time period ?  (Velocity = 41 or 6 .....  in Log message)

                       QEIVelocityGet(),  Returns:   Returns the number of pulses captured in the given time period.

#include <stdbool.h>
#include <stdint.h>
#include "inc/tm4c123gh6pge.h"
#include "inc/hw_memmap.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/interrupt.h"
#include "driverlib/qei.h"
#include "driverlib/uart.h"
#include "utils/uartstdio.h"

int qei_position;
int qei_velocity;

void ConsoleInit()
{
		//UART Init

		SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
		SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

		GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

		UARTStdioConfig(0, 115200, SysCtlClockGet());

		UARTEnable(UART0_BASE);
		UARTprintf("UART Init \n");
}

void QEI1IntHandler(void)
{
	unsigned long status;
	status = QEIIntStatus(QEI1_BASE, false);   
	if ((status & QEI_INTTIMER) == QEI_INTTIMER)
	{
		QEIIntClear(QEI1_BASE, QEI_INTTIMER);
		qei_position = QEIPositionGet(QEI1_BASE);
		qei_velocity = QEIVelocityGet(QEI1_BASE) * QEIDirectionGet(QEI1_BASE);

	}
}

int 
main(void)
{
	
	SysCtlClockSet(SYSCTL_SYSDIV_5 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ); // 40 MHz  200MHz/5 = ?

	ConsoleInit();

	SysCtlPeripheralEnable(SYSCTL_PERIPH_QEI1);
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);
	QEIConfigure(QEI1_BASE, QEI_CONFIG_CAPTURE_A_B | QEI_CONFIG_NO_RESET
	| QEI_CONFIG_QUADRATURE | QEI_CONFIG_SWAP, 0xFFFFFFFF);
	GPIOPinTypeQEI(GPIO_PORTC_BASE, GPIO_PIN_5 | GPIO_PIN_6);


	GPIOPinConfigure(GPIO_PC5_PHA1);
	GPIOPinConfigure(GPIO_PC6_PHB1);
	QEIVelocityConfigure(QEI1_BASE, QEI_VELDIV_2, SysCtlClockGet());
	QEIVelocityEnable(QEI1_BASE);
	QEIEnable(QEI1_BASE);

	QEIIntEnable(QEI1_BASE, QEI_INTTIMER);
	QEIIntRegister(QEI1_BASE, &QEI1IntHandler);
	IntEnable(INT_QEI1);
	IntMasterEnable();

	GPIOPadConfigSet(GPIO_PORTC_BASE, GPIO_PIN_5 | GPIO_PIN_6, GPIO_STRENGTH_8MA_SC, GPIO_PIN_TYPE_STD_WPU);
	while(1)
	{
		SysCtlDelay(SysCtlClockGet()/24);
		UARTprintf("position = %d \n", qei_position);
		UARTprintf("velocity = %d \n\n", qei_velocity);
	}		

	
	 
}

.[ Log Message]

Hello Jame

How many step will it take to complete a full rotation of the motor as seen by the rotary encoder. That would be the MAX positions.

Hello Amit

Is there a problem  MaxPosition value?

Use as Stepper RDK instead of rotary encoder.

Starts, stops, and changes the motor rotation every time the mode switching button is pressed.

The number of pulses per revolution(ppr) is unknown. !!

How do you know what the Maxposition value should be?

Can I apply a quadrature encoder interrupt source to QEI_INTDIR?

thanks

[illustration-1]

[illustration-2]

Hello Amit

Generation Quardrature Plus  is a  Stellaris Micocontroller in Stepper RDK

thanks.

Ch1:  A ,  Ch2 : B ,  Ch3: /A ,  Ch4: /B

I do not know if it is not an input condition.. !!

Why ?

I attached the learned QEI timing diagram.

thanks

[illustration 1 ]

[illustration 2 ]

Hello  Amit

I have another question.

How do I set the source code?

 RPM = (clock x (2^VELDIV) x Speed x 60 ) / (Timer Load  x  ppr x edge)

thanks. 

  [illustration 1]    Description In Datasheet

[illustration 2]    QEI Block Diagram 

I have analyzed the above source code.

ISR :

qei_position = QEIPositionGet(QEI1_BASE);

 qei_velocity = QEIVelocityGet(QEI1_BASE) * QEIDirectionGet(QEI1_BASE);

Main :

QEIConfigure(QEI1_BASE, QEI_CONFIG_CAPTURE_A_B | QEI_CONFIG_NO_RESET| QEI_CONFIG_QUADRATURE | QEI_CONFIG_SWAP, 0xFFFFFFFF);

QEIVelocityConfigure(QEI1_BASE, QEI_VELDIV_2, SysCtlClockGet()/50);

QEIIntEnable(QEI1_BASE, QEI_INTTIMER);

   (reference)

1. void QEIConfigure (uint32_t ui32Base, uint32_t ui32Config, uint32_t ui32MaxPosition)    ,ui32MaxPosition specifies the maximum position value.

2. void QEIVelocityConfigure (uint32_t ui32Base, uint32_t ui32PreDiv, uint32_t ui32Period)  ,ui32Period specifies the number of clock ticks over which to measure the velocity;

3. void QEIIntEnable (uint32_t ui32Base, uint32_t ui32IntFlags)  ,ui32IntFlags is a bit mask of the interrupt sources ( QEI_INTERROR, QEI_INTDIR, QEI_INTTIMER, or QEI_INTINDEX)

  [illustration 3]    Reference  Lib &  SW

Hello  Amit

parameters descriptions are explained below  [illustration 1].

(Reference)

       datasheet attached. ( Chapter QEI ) 

thanks

tm4c123gh6pge_19 Nov 2013(Rev.C).pdf