GD32E231 DIY Competition (8) - Complete the driver of timer 2

hujj

GD32E231 DIY Competition (8) - Complete the driver of timer 2 [Copy link]

    In order to control the length of the alarm sound, I used the function of timer 2. The specific method is to first configure timer 2 to count for one second, then assign the set time length to a variable, and decrement the variable by 1 in the timer interrupt processing. When the variable is equal to 0, turn off the alarm sound. Below is the timer configuration code:

1. void timer_config(void) { /* ----------------------------------------------------------------------- TIMER2CLK is 100KHz Timer 2 CLK is 100kHz TIMER2 channel0 duty cycle = (25000/ 50000)* 100 = 50% ----------------------------------------------------------------------- */ timer_oc_parameter_struct timer_ocintpara; //Define data structure timer_parameter_struct timer_initpara; rcu_periph_clock_enable(RCU_TIMER2); //Enable clock timer_deinit(TIMER2); //Specify timer/* TIMER configuration timer configuration*/ timer_initpara.prescaler = 719; timer_initpara.alignedmode = TIMER_COUNTER_EDGE; timer_initpara.counterdirection = TIMER_COUNTER_UP; timer_initpara.period = 99999; //Timing 1000 milliseconds timer_initpara.clockdivision = TIMER_CKDIV_DIV1; timer_initpara.repetitioncounter = 0; timer_init(TIMER2,&timer_initpara); timer_interrupt_enable(TIMER2, TIMER_INT_UP); //Enable TIMER2 nvic_irq_enable(TIMER2_IRQn, 0); //Set priority to 0(0-2) /* auto-reload preload enable automatic reload preload enable */ timer_auto_reload_shadow_enable(TIMER2); /* auto-reload preload enable */ timer_enable(TIMER2); }

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The following is the code for the timer interrupt processing:

1. void TIMER2_IRQHandler(void) { if(RESET != timer_interrupt_flag_get(TIMER2, TIMER_INT_FLAG_UP)) { if(time>0) time--; } timer_interrupt_flag_clear(TIMER2, TIMER_INT_FLAG_UP); }

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Set the alarm mode in the external interrupt handler, turn on the power of the music IC when the alarm flag is obtained in the main loop, and turn off the power of the music IC after the time is reached:

1. if(mode==110){ alar++; //Alarm count LCD_line_clear(3); LCD_line_clear(4); LCD_write_string(0,3,(uint8_t *) "Alarm record"); LCD_write_value(53,4,3,0,1,alar); date_write(); //Add alarm record LCD_write_value(18,2,3,0,1,recn); LCD_write_value(60,2,3,0,1,addr); mode = 0; if(ala8==4){ //Start music gpio_bit_set(GPIOA, GPIO_PIN_2);//Send start signal delay_1ms(100); gpio_bit_reset(GPIOA, GPIO_PIN_2);//Cancel start signal } else{ if(ala8>0) //Specify alarm sound alarm_type(ala8-1); time = ala9; //Alarm sound duration gpio_bit_reset(GPIOA, GPIO_PIN_3);//Start alarm sound gd_eval_led_off(LED2); } } if(time==0){ gpio_bit_set(GPIOA, GPIO_PIN_3); //Turn off the alarm sound gd_eval_led_off(LED2); } else LCD_write_value(53,3,3,0,0,time); //Show the remaining time

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After testing, the program code basically meets the requirements, but I configured the timer time to be one second, but the actual test found that it was less than one second, about 0.5 seconds, and the reason has not been found yet.

IC爬虫

Good sharing, share more of these domestic MCUs so that everyone can use them and improve them

serialworld

The timer clock frequency is 144hz.

hujj

serialworld posted on 2019-5-17 17:11 The timer clock frequency is 144hz.

timer_initpara.period = 99999; //1000 milliseconds timing The original example was 500 milliseconds timing, and this value is 49999. I thought changing it to 99999 would allow 1000 milliseconds timing. How do I calculate it?

serialworld

The problem is that the maximum value of the timer is 65536, which is too large.

李百仪

How much frequency do you need?

hujj

serialworld posted on 2019-5-17 20:10 The problem is that the maximum value of the timer is 16 bits, which is 65536. 99999 is too large

Thanks for your advice! I didn't notice this problem. No wonder it only takes about half a second. I'll change it back to 5000 milliseconds and try again.

hujj

Li Baiyi posted on 2019-5-17 21:22 How much frequency do you need

Originally I planned to use a 1 second timing, but now I plan to use the original 500 milliseconds of the routine.

月下良缘

Thanks for sharing!

hujj

I changed the value back to 49999, and this time the timing was accurate, 500 milliseconds.