pwm_2ch_timer2_interrupt.c

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// Copyright 2021 IOsetting <iosetting(at)outlook.com>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
#include "fw_hal.h"
 
__BIT dir = SET;
uint8_t dc = 0;
 
INTERRUPT(Timer2_Routine, EXTI_VectTimer2)
{
    PWMA_PWM1_SetCaptureCompareValue(dc);
    UART1_TxHex(dc);
    UART1_TxString("\r\n");
    if (dir)
    {
        dc++;
        if (dc == 0xFF) dir = !dir;
    }
    else
    {
        dc--;
        if (dc == 0) dir = !dir;
    }
}
 
void main(void)
{
    SYS_SetClock();
    // UART1, baud 115200, baud source Timer1, 1T mode
    UART1_Config8bitUart(UART1_BaudSource_Timer1, HAL_State_ON, 115200);
 
    // Set GPIO pins output mode
    GPIO_P1_SetMode(GPIO_Pin_0|GPIO_Pin_1, GPIO_Mode_Output_PP);
    // Turn off PWMA.1 before change its mode
    PWMA_PWM1_SetPortState(HAL_State_OFF);
    PWMA_PWM1N_SetPortState(HAL_State_OFF);
    // Set PWMA.1 port direction output
    PWMA_PWM1_SetPortDirection(PWMB_PortDirOut);
    // Set PWMA.1 output low voltage when counter is less than target value
    PWMA_PWM1_ConfigOutputMode(PWM_OutputMode_PWM_LowIfLess);
    // Enable comparison value preload to make duty cycle changing smooth
    PWMA_PWM1_SetComparePreload(HAL_State_ON);
    // Turn on PWMA.1
    PWMA_PWM1_SetPortState(HAL_State_ON);
    // Turn on PWMA.1 complementary output
    PWMA_PWM1N_SetPortState(HAL_State_ON);
    // Set highest PWM clock
    PWMA_SetPrescaler(0);
    // PWM width = Period + 1 (side alignment), or AutoReloadPeriod * 2 (center alignment)
    PWMA_SetPeriod(0xFF);
    // Counter direction, down:from [PWMA_ARRH,PWMA_ARRL] to 0
    PWMA_SetCounterDirection(PWM_CounterDirection_Down);
    // Enable preload on reload-period
    PWMA_SetAutoReloadPreload(HAL_State_ON);
    // Enable output on PWMA.1P, PWMA.1N
    PWMA_SetPinOutputState(PWM_Pin_1|PWM_Pin_1N, HAL_State_ON);
    // Set PWMA.1 alternative ports to P1.0 and P1.1
    PWMA_PWM1_SetPort(PWMA_PWM1_AlterPort_P10_P11);
    // Enable overall output
    PWMA_SetOverallState(HAL_State_ON);
    // Start counter
    PWMA_SetCounterState(HAL_State_ON);
 
    // 1T mode, prescaler:255+1, frequency: 100
    TIM_Timer2_Config(HAL_State_ON, 0xFF, 100);
    // Timer2 interrupt: ON
    EXTI_Timer2_SetIntState(HAL_State_ON);
    EXTI_Global_SetIntState(HAL_State_ON);
    TIM_Timer2_SetRunState(HAL_State_ON);
 
    while(1);
}