[原创] FRDM-KW41Z入门——PWM驱动舵机

dql2016 2017-5-4 21:10 楼主

舵机型号：SM-S4306R
采用周期为20ms的PWM驱动，PWM脉宽在0.5ms-2.5ms之间；
舵机5V工作电压，电流80mA左右，板卡输出3.3V可直接驱动起来；
定时器时钟为40MHz/8=5MHz,使用PTM1的通道1作为PWM的输出通道，对应GPIO为PTA1；
脉宽为0.5ms~1.5ms时正转，值越小，旋转速度越大；
脉宽为1.5ms~2.5ms为反转，值越大，旋转速度越大；
脉宽为1.5ms时停止，实际不确定，例如可能是1510us；

在例程SDK_2.2_FRDM-KW41Z\boards\frdmkw41z\driver_examples\tpm\simple_pwm基础修改；
修改后pin_mux.c文件如下：

#include "fsl_common.h"
#include "fsl_port.h"
#include "pin_mux.h"
#define PIN6_IDX 6u /*!< Pin number for pin 6 in a port */
#define PIN7_IDX 7u /*!< Pin number for pin 7 in a port */
#define PIN1_IDX 1u /*!< Pin number for pin 1 in a port */
#define SOPT4_TPM1CH1SRC_TPM 00 /*!< TPM1 Channel 1 Input Capture Source Select: TPM1_CH1 signal */
#define SOPT5_LPUART0RXSRC_LPUART_RX 0x00u /*!< LPUART0 Receive Data Source Select: LPUART_RX pin */
/*
* TEXT BELOW IS USED AS SETTING FOR THE PINS TOOL *****************************
BOARD_InitPins:
- options: {coreID: singlecore, enableClock: 'true'}
- pin_list:
- {pin_num: '42', peripheral: LPUART0, signal: RX, pin_signal: TSI0_CH2/PTC6/LLWU_P14/XTAL_OUT_EN/I2C1_SCL/UART0_RX/TPM2_CH0/BSM_FRAME}
- {pin_num: '43', peripheral: LPUART0, signal: TX, pin_signal: TSI0_CH3/PTC7/LLWU_P15/SPI0_PCS2/I2C1_SDA/UART0_TX/TPM2_CH1/BSM_DATA}
- {pin_num: '6', peripheral: TPM2, signal: 'CH, 0', pin_signal: TSI0_CH12/PTA18/LLWU_P6/SPI1_SCK/TPM2_CH0}
* BE CAREFUL MODIFYING THIS COMMENT - IT IS YAML SETTINGS FOR THE PINS TOOL ***
*/
/*FUNCTION**********************************************************************
*
* Function Name : BOARD_InitPins
* Description : Configures pin routing and optionally pin electrical features.
*
*END**************************************************************************/
void BOARD_InitPins(void) {
CLOCK_EnableClock(kCLOCK_PortA); /* Port A Clock Gate Control: Clock enabled */
CLOCK_EnableClock(kCLOCK_PortC); /* Port C Clock Gate Control: Clock enabled */
PORT_SetPinMux(PORTA, PIN1_IDX, kPORT_MuxAlt5); /* PORTA18 (pin 6) is configured as TPM1_CH1 */
PORT_SetPinMux(PORTC, PIN6_IDX, kPORT_MuxAlt4); /* PORTC6 (pin 42) is configured as UART0_RX */
PORT_SetPinMux(PORTC, PIN7_IDX, kPORT_MuxAlt4); /* PORTC7 (pin 43) is configured as UART0_TX */
SIM->SOPT4 = ((SIM->SOPT4 &
(~(SIM_SOPT4_TPM1CLKSEL_MASK))) /* Mask bits to zero which are setting */
| SIM_SOPT4_TPM1CLKSEL(SOPT4_TPM1CH1SRC_TPM) /* TPM1 Channel 1 Input Capture Source Select: TPM1_CH1 signal */
);
SIM->SOPT5 = ((SIM->SOPT5 &
(~(SIM_SOPT5_LPUART0RXSRC_MASK))) /* Mask bits to zero which are setting */
| SIM_SOPT5_LPUART0RXSRC(SOPT5_LPUART0RXSRC_LPUART_RX) /* LPUART0 Receive Data Source Select: LPUART_RX pin */
);
}
main.c修改后如下：
#include "fsl_debug_console.h"
#include "board.h"
#include "fsl_tpm.h"
#include "pin_mux.h"
/*******************************************************************************
* Definitions
******************************************************************************/
#define BOARD_TPM_BASEADDR TPM1
#define BOARD_TPM_CHANNEL 1U
/* Interrupt to enable and flag to read; depends on the TPM channel used */
#define TPM_CHANNEL_INTERRUPT_ENABLE kTPM_Chnl0InterruptEnable
#define TPM_CHANNEL_FLAG kTPM_Chnl0Flag
/* Interrupt number and interrupt handler for the TPM instance used */
#define TPM_INTERRUPT_NUMBER TPM1_IRQn
#define TPM_LED_HANDLER TPM1_IRQHandler
/* Get source clock for TPM driver */
#define TPM_SOURCE_CLOCK CLOCK_GetFreq(kCLOCK_McgFllClk)
/*******************************************************************************
* Prototypes
******************************************************************************/
/*!
* @brief delay a while.
*/
void delay(void);
/*******************************************************************************
* Variables
******************************************************************************/
volatile bool brightnessUp = true; /* Indicate LED is brighter or dimmer */
volatile uint8_t updatedDutycycle = 10U;
volatile uint8_t getCharValue = 0U;
/*******************************************************************************
* Code
******************************************************************************/
/*!
* @brief Main function
*/
int main(void)
{
tpm_config_t tpmInfo;
tpm_chnl_pwm_signal_param_t tpmParam;
tpm_pwm_level_select_t pwmLevel = kTPM_HighTrue;
/* Configure tpm params with frequency 24kHZ */
tpmParam.chnlNumber = (tpm_chnl_t)BOARD_TPM_CHANNEL;
tpmParam.level = pwmLevel;
tpmParam.dutyCyclePercent = updatedDutycycle;
/* Board pin, clock, debug console init */
BOARD_InitPins();
BOARD_BootClockRUN();
BOARD_InitDebugConsole();
/* Select the clock source for the TPM counter as MCGPLLCLK */
CLOCK_SetTpmClock(1U);
PRINTF("\r\n CoreSysClk=%d MHz\r\n",CLOCK_GetFreq(kCLOCK_CoreSysClk)/1000000);
// PRINTF("\r\n PlatClk=%d MHz\r\n",CLOCK_GetFreq(kCLOCK_PlatClk)/1000000);
// PRINTF("\r\n BusClk=%d MHz\r\n",CLOCK_GetFreq(kCLOCK_BusClk)/1000000);
// PRINTF("\r\n FlashClk=%d MHz\r\n",CLOCK_GetFreq(kCLOCK_FlashClk)/1000000);
// PRINTF("\r\n Er32kClk=%d MHz \r\n",CLOCK_GetFreq(kCLOCK_Er32kClk)/1000000);
// PRINTF("\r\n Osc0ErClk=%d MHz \r\n",CLOCK_GetFreq(kCLOCK_Osc0ErClk)/1000000);
// PRINTF("\r\n McgInternalRefClk=%d MHz \r\n",CLOCK_GetFreq(kCLOCK_McgInternalRefClk)/1000000);
PRINTF("\r\n McgFllClk=%d MHz \r\n",CLOCK_GetFreq(kCLOCK_McgFllClk)/1000000);
// PRINTF("\r\n LpoClk=%d MHz \r\n",CLOCK_GetFreq(kCLOCK_LpoClk)/1000000);
/* Print a note to terminal */
PRINTF("\r\nTPM example to output center-aligned PWM signal\r\n");
PRINTF("\r\nIf an LED is connected to the TPM pin, you will see a change in LED brightness if you enter different values");
PRINTF("\r\nIf no LED is connected to the TPM pin, then probe the signal using an oscilloscope");
TPM_GetDefaultConfig(&tpmInfo);
tpmInfo.prescale=kTPM_Prescale_Divide_8;//40MHz/8
/* Initialize TPM module */
TPM_Init(BOARD_TPM_BASEADDR, &tpmInfo);
if(kStatus_Success!=TPM_SetupPwm(BOARD_TPM_BASEADDR, &tpmParam, 1U, kTPM_CenterAlignedPwm, 50, TPM_SOURCE_CLOCK))
{
PRINTF("\r\n SetupPwm Error! \r\n");
}
TPM_StartTimer(BOARD_TPM_BASEADDR, kTPM_SystemClock);
while (1)
{
do
{
PRINTF("\r\nPlease enter a value to update the Duty cycle:\r\n");
PRINTF("Note: The range of value is 0 to 9.\r\n");
PRINTF("For example: If enter '5', the duty cycle will be set to 50 percent.\r\n");
PRINTF("Value:");
getCharValue = GETCHAR() - 0x30U;
PRINTF("%d", getCharValue);
PRINTF("\r\n");
} while (getCharValue > 9U);
updatedDutycycle = getCharValue ;//20ms左右的脉冲，高电平0.5ms~1.5ms(updatedDutycycle为2.5~7.5)正转，值越小，旋转速度越大；1.5ms~2.5ms(updatedDutycycle为7.5~12.5)为反转，值越大，旋转速度越大；
/* Disable channel output before updating the dutycycle */
// TPM_UpdateChnlEdgeLevelSelect(BOARD_TPM_BASEADDR, (tpm_chnl_t)BOARD_TPM_CHANNEL, 0U);
/* Update PWM duty cycle */
TPM_UpdatePwmDutycycle(BOARD_TPM_BASEADDR, (tpm_chnl_t)BOARD_TPM_CHANNEL, kTPM_CenterAlignedPwm,updatedDutycycle);
/* Start channel output with updated dutycycle */
// TPM_UpdateChnlEdgeLevelSelect(BOARD_TPM_BASEADDR, (tpm_chnl_t)BOARD_TPM_CHANNEL, pwmLevel);
PRINTF("The duty cycle was successfully updated!\r\n");
}
}