CCS/TM4C123GH6PM: How Can I use D1 pin instead of D0 pin for PWM output.

Nasim Khan

Part Number: TM4C123GH6PM

Tool/software: Code Composer Studio

Hi,

The workshop for TM4C123GH6PM shows PWM control on D0 pin and code working fine. Could you please let me know what modification I need to do in code in order to get D1 (or generalized) as PWM output pin.

Best regards,

Nasim

over 5 years ago

0 Bob Crosby over 5 years ago

TI__Guru 72500 points

You need to change the pin configuration functions to GPIO_PIN_1 and GPIO_PD1_M1PWM1

	ROM_GPIOPinTypePWM(GPIO_PORTD_BASE, GPIO_PIN_1);
	ROM_GPIOPinConfigure(GPIO_PD1_M1PWM1);

You need to change the PWM configurations to use PWM_GEN_1 and PWM_OUT_1

	PWMGenConfigure(PWM1_BASE, PWM_GEN_1, PWM_GEN_MODE_DOWN);
	PWMGenPeriodSet(PWM1_BASE, PWM_GEN_1, ui32Load);

	ROM_PWMPulseWidthSet(PWM1_BASE, PWM_OUT_1, ui8Adjust * ui32Load / 1000);
	ROM_PWMOutputState(PWM1_BASE, PWM_OUT_1_BIT, true);
	ROM_PWMGenEnable(PWM1_BASE, PWM_GEN_1);

And remember to change PWM_OUT_0 to PWM_OUT_1 twice within the while loop at the end of the main function.

0 Nasim Khan over 5 years ago in reply to Bob Crosby

Prodigy 100 points

Bob,

Thanks a lot for your support. I tried accordingly. It builds, debugs, runs but motor does not move.

Best regards,

Nasim

0 cb1_mobile over 5 years ago in reply to Nasim Khan

Guru 117855 points

Hello,

Nasim Khan said:
It builds, debugs, runs but motor does not move.

Pardon - further facts ARE required:

was PWM Output observed on your desired pin? Ideally - that should be confirmed via a 'Scope Capture.'
unless your motor (btw - the operation of a 'motor' is 'brand-new' information) is extremely small & low voltage - it cannot be 'directly driven' by the MCU's PWM Output - alone! MCU outputs are intelligent - yet not intended to provide the current demanded by 'most all' motors.
a listing (ideally spec) of your motor along w/a schematic detailing the connections between MCU and that motor - will greatly aid your 'helpers.' (almost surely will be required!)

It is 'normal/customary' that a Transistor Power Stage be inserted between the MCU and the Motor. The Power Stage should be able to 'well match' the motor's current AND voltage requirements - both (FAR Beyond) the MCU's output capability...

Depending upon the motor's current & voltage demands - if you attempted a 'direct connection' - the MCU may have been damaged. You are advised to 'Halt all (further) attempts at motor drive' - until you have provided the customary Power Stage as described...

0 Bob Crosby over 5 years ago in reply to Nasim Khan

TI__Guru 72500 points

Nasim,

I am sorry, I gave you incorrect information. There are four PWM generators on each module. Each generator controls two PWM signals. Pin PD1 is on module PWM1_BASE, generator PWM_GEN_0, output PWM_OUT_1_BIT. I told you to use PWM_GEN_1, which is incorrect. The code should look like this:

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#include "driverlib/debug.h"
#include "driverlib/pwm.h"
#include "driverlib/pin_map.h"
#include "inc/hw_gpio.h"
#include "driverlib/rom.h"


#define PWM_FREQUENCY 55

int main(void)
{
	volatile uint32_t ui32Load;
	volatile uint32_t ui32PWMClock;
	volatile uint8_t ui8Adjust;
	ui8Adjust = 83;

	ROM_SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_XTAL_16MHZ);
	ROM_SysCtlPWMClockSet(SYSCTL_PWMDIV_64);

	ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM1);
	ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
	ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);

	ROM_GPIOPinTypePWM(GPIO_PORTD_BASE, GPIO_PIN_1);
	ROM_GPIOPinConfigure(GPIO_PD1_M1PWM1);

	HWREG(GPIO_PORTF_BASE + GPIO_O_LOCK) = GPIO_LOCK_KEY;
	HWREG(GPIO_PORTF_BASE + GPIO_O_CR) |= 0x01;
	HWREG(GPIO_PORTF_BASE + GPIO_O_LOCK) = 0;
	ROM_GPIODirModeSet(GPIO_PORTF_BASE, GPIO_PIN_4|GPIO_PIN_0, GPIO_DIR_MODE_IN);
	ROM_GPIOPadConfigSet(GPIO_PORTF_BASE, GPIO_PIN_4|GPIO_PIN_0, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD_WPU);

	ui32PWMClock = SysCtlClockGet() / 64;
	ui32Load = (ui32PWMClock / PWM_FREQUENCY) - 1;
	PWMGenConfigure(PWM1_BASE, PWM_GEN_0, PWM_GEN_MODE_DOWN);
	PWMGenPeriodSet(PWM1_BASE, PWM_GEN_0, ui32Load);

	ROM_PWMPulseWidthSet(PWM1_BASE, PWM_OUT_1, ui8Adjust * ui32Load / 1000);
	ROM_PWMOutputState(PWM1_BASE, PWM_OUT_1_BIT, true);
	ROM_PWMGenEnable(PWM1_BASE, PWM_GEN_0);

	while(1)
	{

		if(ROM_GPIOPinRead(GPIO_PORTF_BASE,GPIO_PIN_4)==0x00)
		{
			ui8Adjust--;
			if (ui8Adjust < 56)
			{
				ui8Adjust = 56;
			}
			ROM_PWMPulseWidthSet(PWM1_BASE, PWM_OUT_1, ui8Adjust * ui32Load / 1000);
		}

		if(ROM_GPIOPinRead(GPIO_PORTF_BASE,GPIO_PIN_0)==0x00)
		{
			ui8Adjust++;
			if (ui8Adjust > 111)
			{
				ui8Adjust = 111;
			}
			ROM_PWMPulseWidthSet(PWM1_BASE, PWM_OUT_1, ui8Adjust * ui32Load / 1000);
		}

		ROM_SysCtlDelay(100000);
	}

}

0 Nasim Khan over 5 years ago in reply to cb1_mobile

Prodigy 100 points

Hi,

I meant it is the same servo motor ((HextroniK, HXT900) I connected to D0 (orange/ signal cable). When I connected signal cable to D1 it did not work.

Best regards,

Nasim

0 cb1_mobile over 5 years ago in reply to Nasim Khan

Guru 117855 points

Greetings,

Do note vendor Bob's updated post - w/so many (potential) PWM pins available - it proves easy to scramble them. (multi-eyed staff proves great at 'preventing such confusion.')

In light of your 'motor detail' it is suspected that such a small servo motor, 'Is accepting of CMOS Signal Levels.' (it is likely that any current buffering is implemented w/in the small servo motor) Do note that such motors are the 'Exception' - and most always you must deploy a proper 'Power Stage' when mating an MCU to a (more powerful) motor...

0 Nasim Khan over 5 years ago in reply to Bob Crosby

Prodigy 100 points

Thanks a lot Bob,

yes, this code is working to control servo position from D1 pin.

Best regards,

Nasim

Arm-based microcontrollers

Arm-based microcontrollers forum

CCS/TM4C123GH6PM: How Can I use D1 pin instead of D0 pin for PWM output.