時間関連の関数

ch32v003funでArduinoの時間関係の関数が使用できるようにするためのプログラムです。サンプルプログラムをほんの少し書き換えたものです。

• millis()
• micros()
• delay()
• delayMicroseconds()

が使用可能になります。

 

1. // Example for using SysTick with IRQs
2. // 03-25-2023 E. Brombaugh
3. // 05-12-2023 C. Lohr (Modified to reflect updated sysclk)
4. // 09-25-2024 ADBeta (Minor updates to main loop, comments and added
5. // convenient macro function)
6. 
   
7. #include "ch32v003fun.h"
8. #include <stdio.h>
9. 
   
10. // Number of ticks elapsed per millisecond (48,000 when using 48MHz Clock)
11. #define SYSTICK_ONE_MILLISECOND ((uint32_t)FUNCONF_SYSTEM_CORE_CLOCK / 1000 / 8)
12. // Number of ticks elapsed per microsecond (48 when using 48MHz Clock)
13. #define SYSTICK_ONE_MICROSECOND ((uint32_t)FUNCONF_SYSTEM_CORE_CLOCK / 1000000 / 8)
14. 
    
15. // Simple macro functions to give a arduino-like functions to call
16. // millis() reads the incremented systick variable
17. // micros() reads the raw SysTick Count, and divides it by the number of
18. // ticks per microsecond ( WARN: Wraps every 90 seconds!)
19. #define millis() (systick_millis)
20. #define micros() (SysTick->CNT / SYSTICK_ONE_MICROSECOND)
21. 
    
22. #define delay Delay_Ms
23. #define delayMicroseconds Delay_Us
24. 
    
25. // Incremented in the SysTick IRQ - in this example once per millisecond
26. volatile uint32_t systick_millis;
27. 
    
28. // Initialises the SysTick to trigger an IRQ with auto-reload, using HCLK/8 as
29. // its clock source
30. void systick_init(void)
31. {
32.     // Reset any pre-existing configuration
33.     SysTick->CTLR = 0x0000;
34. 
    
35.     // Set the compare register to trigger once per millisecond
36.     SysTick->CMP = SYSTICK_ONE_MILLISECOND - 1;
37. 
    
38.     // Reset the Count Register, and the global millis counter to 0
39.     SysTick->CNT = 0x00000000;
40.     systick_millis = 0x00000000;
41. 
    
42.     // Set the SysTick Configuration
43.     // NOTE: By not setting SYSTICK_CTLR_STRE, we maintain compatibility with
44.     // busywait delay funtions used by ch32v003_fun.
45.     SysTick->CTLR |= SYSTICK_CTLR_STE | // Enable Counter
46.                                         // SYSTICK_CTLR_STRE <- Enable auto reload
47.                      SYSTICK_CTLR_STIE; // Enable Interrupts
48.                                         // SYSTICK_CTLR_STCLK <- HCLK/1; // Set Clock Source to HCLK/8
49. 
    
50.     // Enable the SysTick IRQ
51.     NVIC_EnableIRQ(SysTicK_IRQn);
52. }
53. 
    
54. // SysTick ISR - must be lightweight to prevent the CPU from bogging down.
55. // Increments Compare Register and systick_millis when triggered (every 1ms)
56. // NOTE: the `__attribute__((interrupt))` attribute is very important
57. void SysTick_Handler(void) __attribute__((interrupt));
58. void SysTick_Handler(void)
59. {
60.     // Increment the Compare Register for the next trigger
61.     // If more than this number of ticks elapse before the trigger is reset,
62.     // you may miss your next interrupt trigger
63.     // (Make sure the IQR is lightweight and CMP value is reasonable)
64.     SysTick->CMP += SYSTICK_ONE_MILLISECOND;
65. 
    
66.     // Clear the trigger state for the next IRQ
67.     SysTick->SR = 0x00000000;
68. 
    
69.     // Increment the milliseconds count
70.     systick_millis++;
71. }
72. 
    
73. int main(void)
74. {
75.     SystemInit();
76.     delay(100);
77. 
    
78.     printf("\n\nsystick_irq example\n\r");
79. 
    
80.     // Initialise the IRQ
81.     printf("initializing systick...");
82.     systick_init();
83.     printf("done.\n\r");
84. 
    
85.     // Enable GPIOs for demonstration
86.     funGpioInitAll();
87.     funPinMode(PA2, GPIO_Speed_10MHz | GPIO_CNF_OUT_PP);
88.     funPinMode(PC1, GPIO_Speed_10MHz | GPIO_CNF_OUT_PP);
89.     funPinMode(PC2, GPIO_Speed_10MHz | GPIO_CNF_OUT_PP);
90. 
    
91.     printf("Beginning Loop...\n\r");
92.     while (1)
93.     {
94.         // Toggle the GPIO Pins with a delay - total delay will be 500ms
95.         uint32_t start_millis = millis();
96.         // On
97.         funDigitalWrite(PA2, FUN_HIGH);
98.         funDigitalWrite(PC1, FUN_HIGH);
99.         funDigitalWrite(PC2, FUN_HIGH);
100.         delay(500);
101.         // Off
102.         funDigitalWrite(PA2, FUN_LOW);
103.         funDigitalWrite(PC1, FUN_LOW);
104.         funDigitalWrite(PC2, FUN_LOW);
105.         delay(500);
106.         uint32_t end_millis = millis();
107. 
     
108.         // NOTE: Due to the time it takes for printf(), the Current Millis will
109.         // increment more than 500 per loop
110.         printf("\nMilliseconds taken:\t%lu\n\r", end_millis - start_millis);
111.         printf("Current Milliseconds:\t%lu\n\r", millis());
112.         printf("Current Microseconds:\t%lu\n\r", micros());
113.         printf("SysTick->CNT:\t\t%lu\n\r", SysTick->CNT);
114.     }
115. }
116. 
     

参考URL

GitHub - cnlohr/ch32v003fun