MIMXRT1060-EVK backlight control

[mspenard603]

Is there demo code to control the LCD backlight on the IMXRT1060-EVK?

[ToNato]

Hi NXP,

I'm using RT1060 for our product. I am also having issues with GPIO_B1_15 to generate PWM for backlight. I have some questions.

1- What XBARA is used with GPIO_B1_15_FLEXPWM4_PWMA03? 1, 2, 3?

2- Can you write for us a simple code to configure for properly? I'm trying one day but I cannot configure successfully although, the SDK example is working well on board.

[jingpan]

Hi,

There is no direct backlight demo. In all lcd demo, GPIO_B1_15 works as gpio. In backlight circuit, UM1661 support PWM dimming control. Please refer to the PWM demo in SDK.

Regards,

Jing

[mspenard603]

Hi Jing,

 Thanks, started to look at the PWM demo. The backlight on GPIO_B1_15 is PWM4_PWMA03. Trying to figure out how to plumb that. I have the following but I'm not seeing anything on my scope.

/*
* Copyright (c) 2015, Freescale Semiconductor, Inc.
* Copyright 2016-2017 NXP
* All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/

#include "fsl_debug_console.h"
#include "board.h"
#include "fsl_pwm.h"

#include "pin_mux.h"
#include "fsl_xbara.h"
/*******************************************************************************
* Definitions
******************************************************************************/
/* The PWM base address */
#define BOARD_PWM_BASEADDR PWM4 //PWM1 mls

#define PWM_SRC_CLK_FREQ CLOCK_GetFreq(kCLOCK_IpgClk)

/*******************************************************************************
* Prototypes
******************************************************************************/

/*******************************************************************************
* Variables
******************************************************************************/

/*******************************************************************************
* Code
******************************************************************************/
static void PWM_DRV_Init3PhPwm(void)
{
uint16_t deadTimeVal;
pwm_signal_param_t pwmSignal[2];
uint32_t pwmSourceClockInHz;
uint32_t pwmFrequencyInHz = 1000;

pwmSourceClockInHz = PWM_SRC_CLK_FREQ;

/* Set deadtime count, we set this to about 650ns */
deadTimeVal = ((uint64_t)pwmSourceClockInHz * 650) / 1000000000;

pwmSignal[0].pwmChannel = kPWM_PwmA;
pwmSignal[0].level = kPWM_HighTrue;
pwmSignal[0].dutyCyclePercent = 50; /* 1 percent dutycycle */
pwmSignal[0].deadtimeValue = deadTimeVal;

pwmSignal[1].pwmChannel = kPWM_PwmB;
pwmSignal[1].level = kPWM_HighTrue;
/* Dutycycle field of PWM B does not matter as we are running in PWM A complementary mode */
pwmSignal[1].dutyCyclePercent = 50;
pwmSignal[1].deadtimeValue = deadTimeVal;

/*********** PWMA_SM0 - phase A, configuration, setup 2 channel as an example ************/
PWM_SetupPwm(BOARD_PWM_BASEADDR, kPWM_Module_0, pwmSignal, 2, kPWM_SignedCenterAligned, pwmFrequencyInHz,
pwmSourceClockInHz);

/*********** PWMA_SM1 - phase B configuration, setup PWM A channel only ************/
PWM_SetupPwm(BOARD_PWM_BASEADDR, kPWM_Module_1, pwmSignal, 1, kPWM_SignedCenterAligned, pwmFrequencyInHz,
pwmSourceClockInHz);

/*********** PWMA_SM2 - phase C configuration, setup PWM A channel only ************/
PWM_SetupPwm(BOARD_PWM_BASEADDR, kPWM_Module_2, pwmSignal, 1, kPWM_SignedCenterAligned, pwmFrequencyInHz,
pwmSourceClockInHz);

/*********** PWMA_SM3 - phase C configuration, setup PWM A channel only ************/
PWM_SetupPwm(BOARD_PWM_BASEADDR, kPWM_Module_3, pwmSignal, 1, kPWM_SignedCenterAligned, pwmFrequencyInHz,
pwmSourceClockInHz);

}

/*!
* @brief Main function
*/
int main(void)
{
/* Structure of initialize PWM */
pwm_config_t pwmConfig;
static uint16_t delay;
uint32_t pwmVal = 4;
uint16_t i;

/* Board pin, clock, debug console init */
BOARD_ConfigMPU();
BOARD_InitPins();
BOARD_BootClockRUN();
BOARD_InitDebugConsole();

CLOCK_SetDiv(kCLOCK_AhbDiv, 0x2); /* Set AHB PODF to 2, divide by 3 */
CLOCK_SetDiv(kCLOCK_IpgDiv, 0x3); /* Set IPG PODF to 3, divede by 4 */

/* Set the PWM Fault inputs to a low value */
XBARA_Init(XBARA1);
XBARA_SetSignalsConnection(XBARA1, kXBARA1_InputLogicHigh, kXBARA1_OutputFlexpwm1Fault0);
XBARA_SetSignalsConnection(XBARA1, kXBARA1_InputLogicHigh, kXBARA1_OutputFlexpwm1Fault1);
XBARA_SetSignalsConnection(XBARA1, kXBARA1_InputLogicHigh, kXBARA1_OutputFlexpwm1234Fault2);
XBARA_SetSignalsConnection(XBARA1, kXBARA1_InputLogicHigh, kXBARA1_OutputFlexpwm1234Fault3);

PRINTF("FlexPWM driver example\n");

/*
* pwmConfig.enableDebugMode = false;
* pwmConfig.enableWait = false;
* pwmConfig.reloadSelect = kPWM_LocalReload;
* pwmConfig.faultFilterCount = 0;
* pwmConfig.faultFilterPeriod = 0;
* pwmConfig.clockSource = kPWM_BusClock;
* pwmConfig.prescale = kPWM_Prescale_Divide_1;
* pwmConfig.initializationControl = kPWM_Initialize_LocalSync;
* pwmConfig.forceTrigger = kPWM_Force_Local;
* pwmConfig.reloadFrequency = kPWM_LoadEveryOportunity;
* pwmConfig.reloadLogic = kPWM_ReloadImmediate;
* pwmConfig.pairOperation = kPWM_Independent;
*/
PWM_GetDefaultConfig(&pwmConfig);

/* Use full cycle reload */
pwmConfig.reloadLogic = kPWM_ReloadPwmFullCycle;
/* PWM A & PWM B form a complementary PWM pair */
pwmConfig.pairOperation = kPWM_ComplementaryPwmA;
pwmConfig.enableDebugMode = true;

/* Initialize submodule 0 */
if (PWM_Init(BOARD_PWM_BASEADDR, kPWM_Module_0, &pwmConfig) == kStatus_Fail)
{
PRINTF("PWM initialization failed\n");
return 1;
}

/* Initialize submodule 1 */
pwmConfig.clockSource = kPWM_Submodule0Clock;
pwmConfig.initializationControl = kPWM_Initialize_MasterSync;
if (PWM_Init(BOARD_PWM_BASEADDR, kPWM_Module_1, &pwmConfig) == kStatus_Fail)
{
PRINTF("PWM initialization failed\n");
return 1;
}

/* Initialize submodule 2 the same way as submodule 1 */
if (PWM_Init(BOARD_PWM_BASEADDR, kPWM_Module_2, &pwmConfig) == kStatus_Fail)
{
PRINTF("PWM initialization failed\n");
return 1;
}

/* Initialize submodule 3 the same way as submodule 1 */
if (PWM_Init(BOARD_PWM_BASEADDR, kPWM_Module_3, &pwmConfig) == kStatus_Fail)
{
PRINTF("PWM initialization failed\n");
return 1;
}

/* Call the init function with demo configuration */
PWM_DRV_Init3PhPwm();

/* Set the load okay bit for all submodules to load registers from their buffer */
PWM_SetPwmLdok(BOARD_PWM_BASEADDR, kPWM_Control_Module_0 | kPWM_Control_Module_1 | kPWM_Control_Module_2 | kPWM_Control_Module_3, true);

/* Start the PWM generation from Submodules 0, 1 and 2 */
PWM_StartTimer(BOARD_PWM_BASEADDR, kPWM_Control_Module_0 | kPWM_Control_Module_1 | kPWM_Control_Module_2 | kPWM_Control_Module_3);

delay = 0x0fffU;

while (1U)
{
for (i = 0U; i < delay; i++)
{
__ASM volatile("nop");
}
pwmVal = pwmVal + 4;

/* Reset the duty cycle percentage */
if (pwmVal > 100)
{
pwmVal = 4;
}

/* Update duty cycles for all 3 PWM signals */
PWM_UpdatePwmDutycycle(BOARD_PWM_BASEADDR, kPWM_Module_0, kPWM_PwmA, kPWM_SignedCenterAligned, pwmVal);
PWM_UpdatePwmDutycycle(BOARD_PWM_BASEADDR, kPWM_Module_1, kPWM_PwmA, kPWM_SignedCenterAligned, (pwmVal >> 1));
PWM_UpdatePwmDutycycle(BOARD_PWM_BASEADDR, kPWM_Module_2, kPWM_PwmA, kPWM_SignedCenterAligned, (pwmVal >> 2));
PWM_UpdatePwmDutycycle(BOARD_PWM_BASEADDR, kPWM_Module_3, kPWM_PwmA, kPWM_SignedCenterAligned, (pwmVal >> 3));

/* Set the load okay bit for all submodules to load registers from their buffer */
PWM_SetPwmLdok(BOARD_PWM_BASEADDR, kPWM_Control_Module_0 | kPWM_Control_Module_1 | kPWM_Control_Module_2 | kPWM_Control_Module_3, true);
}
}

[jingpan]

Hi,

have you change the pin configuration in BOARD_InitPins()?

Regards,

Jing