How to resync time from NTP server in esp-idf? - c

I use an ESP32 with esp-idf. I need correct time, therefore i'm trying resync time with NTP server.
I use this example.[1]: https://github.com/espressif/esp-idf/tree/master/examples/protocols/sntp
When i call again the obtain_time() method the device is rebooting.
What do i wrong? I didn't find anything which help.
I (2259) initialise_wifi: Setting WiFi configuration SSID OpenWrt
I (2359) syncTime: I'm runing :)
I (2369) getTimeNow: Time is not set yet. Connecting to WiFi and getting time over NTP.
I (2389) initialize_sntp: Initializing SNTP
I (2389) obtain_time: Waiting for system time to be set... (1/10)
...
I (18389) obtain_time: Waiting for system time to be set... (9/10)
-----The time is correct, but when i'm trying resync with NTP
I (20639) getTimeNow: Time is not set yet. Connecting to WiFi and getting time over NTP.
I (20639) initialize_sntp: Initializing SNTP
assertion "Operating mode must not be set while SNTP client is running" failed: file "/home/lenovov510/esp/esp-idf/components/lwip/lwip/src/apps/sntp/sntp.c", line 600, function: sntp_s
etoperatingmode
abort() was called at PC 0x400d2c6b on core 1
ELF file SHA256: 145d1f5e047670ed10c462ae090b3e64db1c5aa158a9988417a513b2ee801051
Backtrace: 0x4008623c:0x3ffc7e00 0x40086489:0x3ffc7e20 0x400d2c6b:0x3ffc7e40 0x4011e251:0x3ffc7e70 0x400d28b4:0x3ffc7e90 0x400d28c7:0x3ffc7eb0 0x400d2aff:0x3ffc7f10 0x400d2bcd:0x3ffc7fa0
0x4008b569:0x3ffc7fc0
Rebooting...
There is my methods:
This give back the timestamp.
void getDateTime(char *dateTime)
{
char *TAG = "getDateTime";
time_t now;
struct tm timeinfo;
time(&now);
localtime_r(&now, &timeinfo);
char strftime_buf[64];
setenv("TZ", "GTM-2", 1);
tzset();
localtime_r(&now, &timeinfo);
strftime(strftime_buf, sizeof(strftime_buf), "%c", &timeinfo);
sprintf(dateTime, "20%d-%d-%d+%d:%d:%d", timeinfo.tm_year - 100, timeinfo.tm_mon + 1, timeinfo.tm_mday, timeinfo.tm_hour, timeinfo.tm_min, timeinfo.tm_sec);
}
This method trying to update time.
void syncTime()
{
char *TAG = "syncTime";
obtain_time();
}
static void obtain_time(void)
{
static const char *TAG = "obtain_time";
initialize_sntp();
time_t now = 0;
struct tm timeinfo = {0};
int retry = 0;
const int retry_count = 10;
while (retry!=retry_count)// timeinfo.tm_year < (2016 - 1900) && ++retry < retry_count )
{
ESP_LOGI(TAG, "Waiting for system time to be set... (%d/%d)", retry, retry_count);
vTaskDelay(2000 / portTICK_PERIOD_MS);
time(&now);
localtime_r(&now, &timeinfo);
}
}
//----
static void initialize_sntp(void)
{
static const char *TAG = "initialize_sntp";
ESP_LOGI(TAG, "Initializing SNTP");
sntp_setoperatingmode(SNTP_OPMODE_POLL);
sntp_setservername(0, "pool.ntp.org");
sntp_init();
...
//Update the timeInSec and Datettime variable
void updateTimeVariables(void *pvParameter)
{
char *TAG = "updateTimeVariables";
while (1 == 1)
{
getDateTime(dateTime);
timeInSec = getTimeNow();
vTaskDelay(500 / portTICK_PERIOD_MS);
}
vTaskDelete(NULL);
}
//Sync NTP server.
void updateTime(void *pvParameter)
{
char *TAG = "updateTime";
while (1 == 1)
{
syncTime();
vTaskDelay(10000 / portTICK_PERIOD_MS);//1800000 / portTICK_PERIOD_MS);
}
vTaskDelete(NULL);
}
...
xTaskCreate(&updateTime, "updateTime", 4000, NULL, 6, NULL);
xTaskCreate(&updateTimeVariables, "updateTimeVariables", 4000, NULL, 0, NULL);

Looks like you are trying to initialize sntp every time you update time.
Watch for second line of obtain_time function:
static const char *TAG = "obtain_time";
initialize_sntp(); // <<<< THIS ONE.
time_t now = 0;
struct tm timeinfo = {0};
//.....
You have to change you code in a way initialize_sntp would be called only once.

To solve this problem, you need to do a couple of things.
1.) Modify the sntp.c file in users/[username]/.platformio/packages/framework-espidf/components/lwip/lwip/src/apps/sntp/sntp.c and the users/[username]/.platformio/packages/framework-espidf/components/lwip/lwip/include/lwip/apps/sntp.h files and change the following:
a.) in the sntp.c file - change the static void sntp_request(void *arg) to "
void sntp_request(void *arg) to make the function available to other modules. It's somewhere around line 490 in the source file. Also, at line number 160, remove the word "static" to prevent compiler errors.
b.) In the sntp.h header file, add the statement void sntp_request(void *) to make the function prototype available to your code.
Below is my code with modifications to allow calling sntp_request() as needed. I call mine every 30 minutes or so, but you could wait a longer time, maybe one a day, would be sufficient to keep the clock reasonably stable.
bool sntp_1st_init = true; // 1st init call allowed
static void obtain_time(void)
{
if(sntp_1st_init) // doing this again?
{
sntp_setoperatingmode(SNTP_OPMODE_POLL);
sntp_setservername(0, "north-america.pool.ntp.org");
ESP_LOGI(TAG, "Initializing SNTP");
sntp_1st_init = false; // don't call again
sntp_init(); // init and set time
}
else
{
ESP_LOGI(TAG, "Syncing System Time");
sntp_request(NULL); // sync time again
}
// wait for System time to be set by monitoring Date changes
int retry = 0;
const int retry_count = 15;
while(timeinfo.tm_year < (2016 - 1900) && ++retry < retry_count)
{
ESP_LOGI(TAG, "Waiting for system time to be set... (%d/%d)",
retry, retry_count);
vTaskDelay((1 * ONEsec) / portTICK_PERIOD_MS);
time(&now);
localtime_r(&now, &timeinfo);
}
}
The bool "sntp_1st_init" is set true on program startup and set false after 1st sntp init takes place. The call to "sntp_setoperatingmode(SNTP_OPMODE_POLL)" can only be performed one time, so must be placed in the sntp_1st_init code section.
I have confirmed that these changes work by altering the system time to something other than the correct time and observing that the time gets corrected as expected.
The original authors limited the functionality of the sntp code by making the sntp_request() function static, preventing the user from making additional sntp corrections to the computer clock time. Even the best oscillator drifts over time, and if your going to bother to use sntp, you might as well allow for clock drift corrections as well.
Hope this helps.
Jerry
JWM Engineering Group

Luckily the sntp_stop() function doesn't remove previous settings (including servers) so you can use this:
sntp_stop();
sntp_init();
On the first run the sync takes ~30s and subsequent runs ~500ms.
I place this in a FreeRTOS task:
#include "esp_sntp.h"
#include "freertos/task.h"
void update(void* pvParameters) {
while (true) {
sntp_stop();
sntp_init();
vTaskDelay(pdMS_TO_TICKS(60 * 60 * 1000));
}
}
void setup(void) {
// Add your SNTP setup code here
xTaskCreate(update, "NtpUpdate", 2048, NULL, tskIDLE_PRIORITY,
&updateHandle);
}

Through issue 4386 the SNTP documentation has been updated with the following:
An application with this initialization code will periodically
synchronize the time. The time synchronization period is determined by
CONFIG_LWIP_SNTP_UPDATE_DELAY (default value is one hour). To modify
the variable, set CONFIG_LWIP_SNTP_UPDATE_DELAY in project
configuration.
All you need is to use the below code in your application:
sntp_setoperatingmode(SNTP_OPMODE_POLL);
sntp_setservername(0, "pool.ntp.org");
sntp_init();

Related

Event-based task management using FreeRTOS

I'm trying to pick up C, using an esp32. While looking at exactly how FreeRTOS works, I found the following page regarding how to use the tasks, and best practices etc.
https://www.freertos.org/implementing-a-FreeRTOS-task.html
According to this page, to prevent starvation, tasks should be event based. Regarding what I am trying to achieve, I will try to provide a very simplified example.
Background
I have a LCD screen, which should display data from a sensor. The data shown on the LCD will be done using a task, which according to the documentation, should never exit and should be event driven to prevent starvation.
I have a way of controlling the data shown on the LCD screen, which would be a rotary encoder. This encoder can be clicked, which should refresh the sensor's data.
Question
How would I implement the event based tasks, which are described on the FreeRTOS page, in this specific context? I had a look at the documentation and the "simple" example projects on their github, but as a beginner within C and embedded, they were extremely overwhelming.
Simple demo code
void update_sensor_task(void *pvParameters)
{
// Ensure the task keeps on running
for( ; ; )
{
if(event_update_sensor) // How would I be able to notify the task that this should be run?
{
// update the data
}
}
// Tasks should not be returning, but if they happen to do so, ensure a clean exit
vTaskDelete(NULL);
}
void screen_temperature_task(void *pvParameters)
{
for(; ;)
{
if(event_sensor_updated)
{
// Update the lcd screen with the new data
}
}
vTaskDelete(NULL);
}
void on_rotary_clicked(void *pvParameters)
{
// Notify the sensor task that it should be updating?
}
EDIT:
By using what has been marked as the correct answer, I have managed to get it to work by implementing it the following way:
/* Queue used to send and receive the data */
QueueHandle_t xStructQueue = NULL;
/* Struct which shall be used to hold and pass around the data for the LCD screen*/
struct LcdData
{
int current_temp;
int current_humidity;
} xLcdData;
void initialize_queues(void)
{
xLcdData.current_humidity = 0;
xLcdData.current_temp = 0;
xStructQueue = xQueueCreate(
/* The maximum number of items the queue can hold*/
5,
/* The size of each struct, which the queue should be able to hold */
sizeof( xLcdData )
);
if(xStructQueue == NULL)
{
ESP_LOGE(TAG, "Queue has not been initialized successfully");
}
}
void screen_temperature_task_simplified(void *pvParameters)
{
int counter = 0;
for(; ;)
{
struct LcdData xReceivedStructure;
BaseType_t result;
result = xQueueReceive(xStructQueue, &xReceivedStructure, ( TickType_t ) 10);
if(result == pdPASS)
{
counter = counter + 1;
char snum_current_counter[12];
sprintf(snum_current_counter, "%d", counter);
i2c_lcd1602_clear (lcd_info);
i2c_lcd1602_write_string (lcd_info, snum_current_counter);
}
}
vTaskDelete(NULL);
}
void update_sensor_struct(void)
{
xLcdData.current_temp = DHT11_read().temperature;
xLcdData.current_humidity = DHT11_read().humidity;
// Log the results in the console
printf("Temperature is %d \n", xLcdData.current_temp);
printf("Humidity is %d\n", xLcdData.current_humidity);
ESP_LOGI(TAG, "Data has been updated");
}
void on_rotary_clicked_simplified()
{
ESP_LOGI(TAG, "Rotary encoder has been clicked!");
// Update the struct which holds the data
update_sensor_struct();
/* Send the entire struct to the queue */
xQueueSend(
/* The handle of the queue */
xStructQueue,
/* The adress of the struct which should be sent */
(void *) &xLcdData,
/* Block time of 0 says don't block if the queue is already full.
Check the value returned by xQueueSend() to know if the message
was sent to the queue successfully. */
( TickType_t ) 0
);
}
I use FRTOS and event driven development.
The typical flow here would be:
for(;;)
{
BaseType_t result;
result = xQueueReceive(LCD_Event_Queue, &someLCDEvent, QUEUE_TIMEOUT);
if (result == pdPASS)
{
/* We have new event data in someLCDEvent; Use that data to update the LCD */
}
else
{
/* No new event, do some brief idle-time processing if necessary */
}
}
In brief, wait up to QUEUE_TIMEOUT time for a new event to arrive.
If a new event arrives within that timeframe successfully, then process the data in that event and update your screen.
If a new event does not arrive, you have an opportunity to do some other maintenance work.
Designing and defining the structure-type of someLCDEvent, and putting data into the queue is a big topic, and will depend a lot on your specific project.

How to send messages in PM server Minix

So I'm trying to create a new system call on PM server. My question is, how can I send some kind of message to function.
in IPC server all I had to do is add my system call to the list, because all functions there were defined as (*func)(message *)
(...)/servers/ipc/main.c
static struct {
int type;
int (*func)(message *);
int reply; /* whether the reply action is passed through */
} ipc_calls[] = {
(...)
{ IPC_MYNEWSIGNAL, do_something, 1 },
};
but in PM in table.c functions are defined as
(...)/servers/pm/table.c
int (* const call_vec[NR_PM_CALLS])(void) = {
(...)
CALL(PM_GETSYSINFO) = do_getsysinfo
}
and if I try to pass function with signature
int do_something(message *m)
I will get error:
Incompatible pointer types: initializing int (*const)(void) with int (message *)
What is the correct way to create signal on PM server if I need to receive some kind of information?
As far as I understood from the question, you want to receive arguments inside the syscall handler. Let's take as an example the library function clock_settime from libc.
int clock_settime(clockid_t clock_id, const struct timespec *ts)
{
message m;
memset(&m, 0, sizeof(m));
m.m_lc_pm_time.clk_id = clock_id;
m.m_lc_pm_time.now = 1; /* set time immediately. don't use adjtime() method. */
m.m_lc_pm_time.sec = ts->tv_sec;
m.m_lc_pm_time.nsec = ts->tv_nsec;
if (_syscall(PM_PROC_NR, PM_CLOCK_SETTIME, &m) < 0)
return -1;
return 0;
}
As you can see it writes the args inside message struct and passes to _syscall. OK, now have a look at syscall handler for PM_CLOCK_SETTIME which is mounted in table.c.
int do_gettime()
{
clock_t ticks, realtime, clock;
time_t boottime;
int s;
if ( (s=getuptime(&ticks, &realtime, &boottime)) != OK)
panic("do_time couldn't get uptime: %d", s);
switch (m_in.m_lc_pm_time.clk_id) {
case CLOCK_REALTIME:
clock = realtime;
break;
case CLOCK_MONOTONIC:
clock = ticks;
break;
default:
return EINVAL; /* invalid/unsupported clock_id */
}
mp->mp_reply.m_pm_lc_time.sec = boottime + (clock / system_hz);
mp->mp_reply.m_pm_lc_time.nsec =
(uint32_t) ((clock % system_hz) * 1000000000ULL / system_hz);
return(OK);
}
It becomes clear that the argument is a global variable named m_in. A little bit more search shows that it comes from glo.h
/* The parameters of the call are kept here. */
EXTERN message m_in; /* the incoming message itself is kept here. */
I suppose that MINIX will handle setting and accessing the global variable, so you don't need to explicitly write to it.
Have a look at point 7 Passing a parameter to a system call here. To understand how to compile the kernel correctly refer to this post.

What is the purpose of xTaskAbortDelay function in free rtos?

I have two task in which i am receving data from bluetooth and if i receive a particular hex value , i want a task(which is Toggling LED State) to run on the basis of the received data.
If there was no data received , then both task should run as per they are scheduled.
I have been trying to use xTaskAbortDelay function , the task does run from the input from bluetooth data, however , after that the LED task is running continously.
Does xTaskAbortDelay creating some problem here?
Should I use something else to achieve the same functionality?
TaskHandle_t lora_send_data_handle;
TaskHandle_t ble_send_data_handle;
TaskHandle_t test_data_handle;
static void button_task_check(void * pvParameter)
{
TickType_t xLastWakeTime;
const TickType_t xFrequency = 1024;
xLastWakeTime = xTaskGetTickCount();
while(1)
{
nrf_delay_ms(100);
SEGGER_RTT_printf(0,"%s","INSIDE SWITCHING\r\n");
xTaskAbortDelay(test_data_handle);
vTaskDelayUntil( &xLastWakeTime, (TickType_t) 1024);
}
}
/*TASK TO RUN LEDS CHECK */
static void led_task_check(void * pvParameter)
{
TickType_t xLastWakeTime;
const TickType_t xFrequency = 122880;
xLastWakeTime = xTaskGetTickCount();
while(1)
{
SEGGER_RTT_printf(0,"%s","TEST TASK\r\n");
nrf_gpio_pin_write(RED,1);
nrf_gpio_pin_write(GREEN,1);
nrf_gpio_pin_write(BLUE,1);
nrf_gpio_pin_write(RED,0);
nrf_gpio_pin_write(GREEN,1);
nrf_gpio_pin_write(BLUE,1);
nrf_delay_ms(1000);
nrf_gpio_pin_write(RED,1);
nrf_gpio_pin_write(GREEN,0);
nrf_gpio_pin_write(BLUE,1);
nrf_delay_ms(1000);
nrf_gpio_pin_write(RED,1);
nrf_gpio_pin_write(GREEN,1);
nrf_gpio_pin_write(BLUE,0);
nrf_delay_ms(1000);
nrf_gpio_pin_write(RED,0);
nrf_gpio_pin_write(GREEN,0);
nrf_gpio_pin_write(BLUE,0);
nrf_delay_ms(1000);
vTaskDelayUntil( &xLastWakeTime, (TickType_t) 122880);
}
}
int main(void)
{
uint8_t rx_qspi[255];
SEGGER_RTT_printf(0,"%s","reset\r\n");
nrf_delay_ms(100);
xQueue1 = xQueueCreate(1, 30);
ret_code_t err_code;
err_code = nrf_drv_clock_init();
SEGGER_RTT_WriteString(0, err_code);
UNUSED_VARIABLE(xTaskCreate( button_task_check, "t", \
configMINIMAL_STACK_SIZE + 200, NULL,3, &lora_send_data_handle));
UNUSED_VARIABLE(xTaskCreate(led_task_check, "et", \
configMINIMAL_STACK_SIZE + 200, NULL, 2, &test_data_handle));
vTaskStartScheduler();
while(1);
}
Reputation to low to comment. From what you say, everything is working as you said. Need more information:
What does the LED task looks like?
Do you use preemptive or cooperative scheduler (#define configUSE_PREEMPTION 1 in freertosconfig.h file).
What are the priorities of the three tasks?
Something else to consider is: do you put the task back in BLOCKED state after it has served it's purose? You should check that first. How do you block the task in the first place?
Maybe try using calling vTaskResume( <LED task handle> ) from the bluetooth tasks and calling vTaskSuspend() from the LED task once it has finished it's job. I don't personally think this is the best approach, but it should work.

scheduling tasks in linux kernel module everyday at a user provided time

I am writing a linux kernel module which schedules a task using schedule_delayed_work at a particular time which in turn send a signal to a user space program to do some task.
What I did is manually given the time in milliseconds (say 5000ms) and changed it to jiffies using "msec to jiffies" function and tested it and worked.
My use case is that the user will give a time (say 5 pm) and the module has to schedule it to send the signal everyday at 5 pm to the user program. I am totally confused in how to calculate the milliseconds from the user given time for everyday basis.
I used workqueue to create a queue and then the task to accomplish and doing the scheduling.
My kernel module:
static void wq_handler_function(struct work_struct *work);
static unsigned long delay;
static struct workqueue_struct *my_wq; // my workqueue
static DECLARE_DELAYED_WORK(my_work, wq_handler_function); //my work/task
static void wq_handler_function(struct work_struct *work)
{
printk(KERN_DEBUG "handler function called\n");
if(my_wq)
{
/*Do some work like sending signal to user space*/
schedule_delayed_work(&my_work, delay); /*reschedule after the first scheduled time finished*/
}
}
int sig_init_module(void)
{
printk(KERN_DEBUG "signal module initiated\n");
delay = msecs_to_jiffies(5000); //Manually given 5000ms (5 sec) for scheuling
if(!my_wq)
my_wq = create_workqueue("my_queue");
if(my_wq)
{
schedule_delayed_work(&my_work, delay); /*schedule for the first time while module initiates*/
}
return 0;
}
void sig_cleanup_module(void)
{
flush_scheduled_work();
cancel_delayed_work_sync(&my_work);
flush_workqueue(my_wq);
destroy_workqueue(my_wq);
printk(KERN_DEBUG "signal module removed\n");
}
module_init(sig_init_module);
module_exit(sig_cleanup_module);
Kindly help me to have a solution for this. Thanks in advance!!!.
I don't understand why kernel modification would be desirable or necessary. If you want something periodically done (e.g. log rotation), add it to cron. Another option would be to use timerfd.
use mktime() function in kernel code which takes the wall time as arguments and directly returns the jiffies value.
For info about mktime, see this http://www.makelinux.net/ldd3/chp-7-sect-2

Why does my Pebble watchface not update the time every minute?

I'm learning watchface development. I have been following the Pebble guide closely, so 80% of my code is the same as their sample code. I'm probably missing something very small, but my face does not seem to be correctly subscribed to the time service.
What am I doing wrong?
In init(), I have:
tick_timer_service_subscribe(MINUTE_UNIT, tick_handler);
tick_timer_service_subscribe(DAY_UNIT, tick_handler);
Here's tick_handler:
static void tick_handler(struct tm *tick_time, TimeUnits units_changed) {
update_time();
}
Here's update_time:
static void update_time() {
time_t temp = time(NULL);
struct tm *tick_time = localtime(&temp);
static char time_buffer[] = "00:00";
static char date_buffer[] = "00/00/00";
if (clock_is_24h_style() == true) {
strftime(time_buffer, sizeof(time_buffer), "%H:%M", tick_time);
} else {
strftime(time_buffer, sizeof(time_buffer), "%I:%M", tick_time);
}
text_layer_set_text(s_time_layer, time_buffer);
strftime(date_buffer, sizeof(date_buffer), "%D", tick_time);
text_layer_set_text(s_date_layer, date_buffer);
}
The face only updates the time when it first loads (by calling update_time).
TimeUnits is a bit mask. You set a mask and then call tick_timer_service_subscribe once. Your second call using DAY_UNITS is changing your subscription. To subscribe to both units, you bitwise-or your mask bits:
tick_timer_service_subscribe(MINUTE_UNIT | DAY_UNIT, tick_handler);
Notice how your tick handler has a TimeUnits argument. That argument tells you which unit triggered the handler. In your case, you always want to update the time and it appears DAY_UNIT is redundant. But you could do this:
static void tick_handler(struct tm *tick_time, TimeUnits units_changed) {
if( (units_changed & MINUTE_UNIT) != 0 ) {
/* Minutes changed */
}
if( (units_changed & DAY_UNIT) != 0 ) {
/* Days changed */
}
}

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