ESP32-S3 hardware timer interrupt doesn't work stable

[markelov69]

Hi, everyone.
I have timer and 1 tcp server task.
The problem is:


My timer interrupt code for debug is:

Code: [Select all] [Expand/Collapse]

1. static bool IRAM_ATTR timer_group_isr_callback(void *args)
2. {
3.     BaseType_t high_task_awoken = pdFALSE;
4.  
5.     gpio_set_level(GPIO_NUM_48, 1);
6.     gpio_set_level(GPIO_NUM_48, 0);
7.  
8.     return high_task_awoken == pdTRUE; // return whether we need to yield at the end of ISR
9. }

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Timer init code is:

Code: [Select all] [Expand/Collapse]

1. static void example_tg_timer_init(int group, int timer, bool auto_reload, int timer_interval_sec)
2. {
3.     /* Select and initialize basic parameters of the timer */
4.     timer_config_t config = {
5.         .divider = TIMER_DIVIDER,
6.         .counter_dir = TIMER_COUNT_UP,
7.         .counter_en = TIMER_PAUSE,
8.         .alarm_en = TIMER_ALARM_EN,
9.         .auto_reload = auto_reload,
10.     }; // default clock source is APB
11.     timer_init(group, timer, &config);
12.  
13.     /* Timer's counter will initially start from value below.
14.        Also, if auto_reload is set, this value will be automatically reload on alarm */
15.     timer_set_counter_value(group, timer, 0);
16.  
17.     /* Configure the alarm value and the interrupt on alarm. */
18.     timer_set_alarm_value(group, timer, timer_interval_sec);
19.     timer_enable_intr(group, timer);
20.    
21.     example_timer_info_t *timer_info = calloc(1, sizeof(example_timer_info_t));
22.     timer_info->timer_group = group;
23.     timer_info->timer_idx = timer;
24.     timer_info->auto_reload = auto_reload;
25.     timer_info->alarm_interval = timer_interval_sec;
26.     timer_isr_callback_add(group, timer, timer_group_isr_callback, timer_info, 0);
27.    
28.  
29.     timer_start(group, timer);
30. }
31.  
32. // ....
33.  
34. example_tg_timer_init(TIMER_GROUP_1, TIMER_1, true, (1814 / 2));

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What can i do, to make timer interrupts work stable?

[username]

I tired your code on my ESP32-S3, it was missing some parts like:

#define TIMER_DIVIDER (16) // Hardware timer clock divider

typedef struct {
int timer_group;
int timer_idx;
int alarm_interval;
bool auto_reload;
} example_timer_info_t;

But it worked fine for me.

Attach0.jpg (757.67 KiB) Viewed 4120 times

[markelov69]

I use

Code: [Select all] [Expand/Collapse]

1. #define TIMER_DIVIDER         (2)  //  Hardware timer clock divider

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To reply my issue you need to add some task, not only timer, in my case it tcp_server.

Code: [Select all] [Expand/Collapse]

1. xTaskCreate(tcp_server_task, "tcp_server", 4096, NULL, 1, NULL);

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And when it start to receive data through wi-fi i see unstable interrupts.

[username]

To reply my issue you need to add some task, not only timer, in my case it tcp_server.

Yes, I did that. you did not mention you were doing other things. So sounds like the problem lies there.

[ESP_Sprite]

Could you try starting a task pinned to core 1 and initializing the timer interrupt there? Possibly your timer is pre-empted by WiFi interrupts at some point.

[Weizzh]

Hi，is it possible that a timer ISR operations are pre-empted by WiFi interrupts?
I have faced an identical problem: when wifi is working, especially transmitting data package(about 5kB/package) through mqtt, the timer isr sometimes misses.

Could you try starting a task pinned to core 1 and initializing the timer interrupt there? Possibly your timer is pre-empted by WiFi interrupts at some point.

[ESP_Sprite]

Yes, it's possible for WiFi to pre-empt other interrupts.