_delay_ms is (most probably) AVR implementation for delay. I would like to break this second loop when the stop button is pressed. This the first of a new set of tutorials by SwitchDoc Labs on using the ESP32, the follow on chip to the popular ESP8266. Note that this is busy-waiting, so unlike vTaskDelay it does not allow other tasks to run (it just burns CPU cycles. I'm totally new to programming and electronics, it would be very helpful if someone helped me figure this out. as well as by blocking task in loop(), using delay() function as an example. The aim of our project is to connect a 5mm LED with one of the 30 pins available for ESP32, configure that GPIO pin as a digital output pin and then toggle its state after a delay of a few seconds to show a blinking effect. ESP32 supports two major power saving modes: Light-sleep and Deep-sleep. This means our application has 2 tasks: ESP32 task will print the text “this is ESP32 task” and the second task will print “this is another. ESP32 Repeatedly Crashes with FreeRTOS Task. 1 seconds to run and the vtaskDelay is set to 2 seconds, that means that the next time this task will be scheduled after 2. Right now I see on the monitor that the loop in the vTask_Manage_STA_Connection runs a single time. I believe this is related to CONFIG_FREERTOS_HZ. Task2 running on core 1 receives CANBUS data from a MCP2515 IC (through SPI) and print this data to serial @1Mbps baud. I also tried putting those two functions (or whatever they are called after. Timer callbacks can be dispatched by two methods: Arduino ESP32 is built over FreeRTOS and actually the main program is put in a loopTask . Delay a task until a specified time. I want to try the inits in a loop, with a short delay between attempts, and I want the watchdog to reset the ESP after say 5 seconds. Description. NORA-W106 (ESP32-S3) NORA-W106 module. Unless it is a linear and very simple program , do not use this. But for now, I just observe the input on serial port and work with only one submit bar. ps2keyboard-esp32c3 - PS/2 keyboard implementation for ESP32-C3. I promise this one is definitely about dual core issues and not my crappy array management. Put your current code from gpio_isr_handler () in a task in an infinite loop with a , start the task in app_main () and have gpio_isr_handler () just wake the task. h" #include "freertos/task. The first advantage we will discuss is accurate timing. Mỗi nhóm có hai bộ định thời đa dụng, cung cấp tổng cộng bốn bộ. start_Manage_STA_Connection () is called in main. The concrete device is an ESP32-CAM and it is running at 80MHz at approx 25°C room temperature. But if any task takes more than the expected time, all other tasks will be delayed and you will notice the delay in execution. I dont get any delay even if I add some different delays. Solution. In the main. h" #include "esp_log. The ROM function ets_delay_us() (defined in rom/ets_sys. Learn more about Teams #include "freertos/FreeRTOS. In my FreeRTOS project, I am using another timer, namely TIM1, therefore using HALDelay() doesn’t give me correct behaviour. be connected on a same SPI bus (sharing a single ESP32 SPI peripheral). It’s scheduled to run on a delay of 50 milliseconds. tool-cmake. The ROM function ets_delay_us() (defined in rom/ets_sys. Temperature sensor and telegram messages. I promise this one is definitely about dual core issues and not my crappy array management. One is to use the semaphore (s. The ESP32 has two cores, with 32 interrupts each. More knowledgeable programmers usually avoid the use of delay () for timing of events longer than 10’s of milliseconds unless the Arduino sketch is very simple. This callback function is called from the esp_timer task each time the timer elapses. Delay in mS. esp_timer set of APIs provides one-shot and periodic timers, microsecond time resolution, and 64-bit range. io Flash Frequency: xxxx Upload Speed: xxxx Hi! When I started to develop on a Arduino everything was singlethreaded, and I was in full control of the. Otherwise delay might be even few days (depends on higher priority tasks. cpp 📋 Copy to clipboard ⇓ Download. n] * 4 ms resp. ESP32 有個先進武器 - 雙核多工，現在有機會派上用場了。 用 xTaskCreatePinnedToCore() 建立一個獨立 Task，在 Task 跑無窮迴圈 delay(1) 1ms analogRead() 取樣一次，循環記錄 100 個點。Since my task takes approximately 0. This is vTaskDelay ( pdMS_TO_TICKS ( 10 ) ) a delay of 10mSec, this vTaskDelay ( 10 ) is a delay of 10 clock ticks. g. The ESP-IDF has support for two types of watchdogs: The Interrupt Watchdog Timer and the Task Watchdog Timer (TWDT). vTaskDelay (ledMode / portTICK_PERIOD_MS) when I call esp_err_t err = nvs_flash_init (); the result is this: Code: Select all. In this guide, we will show you how to use FreeRTOS timers and delays using ESP32 and ESP-IDF. Use vTaskSuspend () at the start of the loop to have the task wait till it's woken up. As we have been covering in previous tutorials, the ESP32 has two Tensilica LX6 cores [1] which we can use to execute code. // "iBeacons-ESP32-Tracker. Hi there! I'm currently trying to get started with Rust on ESP32 controllers. Posted by rtel on December 24, 2014. When you do delay (1000) your Arduino stops on that line for 1 second. You should use it if you are using arduino, and also you should post in the arduino forum. There will be 2 task, first task will run on core 0, communicating with sensors to collect data at 4000SPS, using SPI bus. ESP-IDF is the official development framework for the ESP32, ESP32-S, ESP32-C, ESP32-H and ESP32-P Series SoCs. ESP32とArduinoIDEでキューを送りたい. After that, you can use vTaskDelay (. The second argument is the name of the task for descriptive purposes. Please check the following example with and without the delay () before the WD reset function. vTaskDelay() specifies a time at which the task wishes to unblock relative to the time at which vTaskDelay() is called. Running a number of times or forever. Add one (increment) the notification value. You will get a notification that the project has been created. After that, we will get the priority of the setup function. Yes, I see now that you can change the tick rate. For this, we need to pass the handle of the task to be resumed. The device sends data via mqtt every 1. Internally, esp_timer uses a 64-bit hardware timer, where the implementation depends on the target. Has. esp32s3-box-examples - Various. Manage FreeRTOS tasks - Suspend, Delay, Resume, Delete. Arduino doesn't currently enable these features. Initially, the tasks must run in this predefined order. ryancasler: FreeRTOS events will then run on core 0 instead of core 1. lib_deps = feilipu/FreeRTOS @ 10. lib_deps = feilipu/FreeRTOS @ 10. For that, there are two tasks: the first task reads the input through I2C and stores those in a queue; the second tasks takes the value from the queue. That method blocks ESP32 from doing other tasks. This function is used to configure the timer. 05s and I want. execute() in loop(), which pops off the next task that is. For example delayMicroseconds(2) takes 330 cycles, corresponding to a delay of more than 4µs, or double what was requested, when running at 80MHz to save power. The Task examples that I have seen are very simple with Task1 and Task2 being called (or some variation of that). ESP32: shared variable between tasks. Thank you for your quick reply. The ESP32 understandably doesn't like having to load code from flash to RAM in order to service an interrupt. Otherwise, a task with a higher priority may preempt the task that calls. Sometimes my ESP32 looses. 芦 锟絯 锟斤拷锟斤拷（Receive raw data from mesh network and forward it directly to serial port. The task that lights up the LED connected to GPIO11 has the lowest priority of 0. Multitasking with asyncio. This example delays by 500ms: esp-idf-equivalent-to-arduino-delay. This number corresponds to the tick which is the frequency of the chip. You do not have the required permissions to view the files attached to this post. For example, we have two tasks: Demo_Task and Demo_Task2. As soon as you need to do a few things at the same time, you. Step 1: Introduction. ESP32 Dual Core Programming. Also test unpinned Task2. I want to run FreeRTOS on ESP32. 1. This is a single task using the serial port. . The HTTP server runs normally, but "crashes", page times out. inoUse variables with both cores and tasks ESP32. cpp. TX function will block task until all data have been sent out. Hi all, I have been fighting a really annoying bug lately and I must be missing something important here. 1 seconds to run and the vtaskDelay is set to 2 seconds, that means that the next time this task will be scheduled after 2. Re: FreeRTOS Task notification crashing esp32. The first argument is the name of the function. GMT +8 = 28800. I really don't understand why when I'm change the task from core 1 to core 0. Because there are more interrupt sources than interrupts, sometimes it makes sense to share an interrupt in multiple drivers. Ask Question Asked 1 year, 3 months ago. Can I predict or calculate in advance and with accuracy the delay time which is required within a task in order to prevent the watchdog task from triggering (in order for example to know if the introduced delay could interfere with more time-critical events like missing serial input that is faster than 10 ms) ?. Not sure. Se estiver utilizando a vTaskDelay, estará evidenciando em seu código a utilização dos recursos do. Code: Select all #include <string. The aim is the do high speed analog reads and blink the led But the problem I have with ESP32 is that if I use vTaskDelay(1); the maximum read speed is ~1mS On the otherhand if I use yield() the led does not blink. If your application requires that you constantly. The loop () in the above code doesn't use a delay, and has no output either. You can use a semaphore. We have set it to ‘2048’. Good afternoon, I want to make a continuously operable gateway that measures temperature with esp32. h. Task B and C has the same periodicity but C has higher priority. So, it means that the task will be blocked during the delay time [5] and the scheduler can attribute the CPU to other free task. Is it possible that within a task running on Core 0 the esp_task_wdt_reset () to fail to reset the WD timer? Board: ESP-WROOM-32 WEMOS. The process is as follows. Most Arduino sensor libraries use calls to delay() to wait for the reading to become available. The RTOS task does not consume any CPU time when it is in the Blocked state. I am using ESP32 CAM module for a line follower robot. Currently, the largest value that will produce an accurate delay is 16383; larger values can produce an extremely short delay. 8V/3. Hello. ESP32 is a series of low cost, low power system on a chip microcontrollers with integrated Wi-Fi and dual-mode Bluetooth. @Whandall perhaps you can help out making this ESP32 task example more indicative of what ESP32 can do. This is the documentation for Espressif IoT Development Framework ( esp-idf ). House cleaning tasks will be performed when there is no code in loop(), so no issue there. Also, AsyncTCPSock, which starts its own task. I'm basicly testing the sending data from the ESP32 to Firebase. I am new to ESP32 programming, coming from Arduino, and I am struggling with the task watchdog timer. I have found the solution of this issue. Shizen: I can use vTaskDelay () for days on a task and the ESP32 will handle the timing. The wakeup from deep sleep is not a complete reboot of the CPU. 追記：プログラム解説 setup内I usually create a lowest priority FreeRTOS task that just loops and calls the feed method with a delay less then the timeout, giving enough time for higher priority "business logic" to run. The Interrupt Watchdog Timer and the TWDT can both be enabled using Project Configuration Menu, however the TWDT can also be enabled during runtime. queue_size – UART event queue size/depth. These tasks are waiting for the key and the low priority task has chance to hold the key then it will block the high priority task and continue executing. INCLUDE_vTaskDelayUntil must be defined as 1 for this function to be available. • Both the SETUP and the main functions of the LOOP are executed with a priority of 1 and in core 1. Code: Select all. The maximum time to wait in the Blocked state for a notification to be received if a notification is not already pending when xTaskNotifyWait () is called. xTaskCreate () for first task. ). For ESP-IDF target, we have chosen ESP32 module. If you don't want to use vTaskDelay maybe you could make the priority of the IDLE and the MAIN task equal. I have a esp-wroom-32 module(esp32 dev module) and use arduino IDE, my task is to generate 2 pulses on different pins with as much accuracy as possible: 1) make GPIO_NUM_2 and GPIO_NUM_4 go HIGH 2)Generate single shot pulses on a button press with predefined delay: 2. run() to a specific core on ESP32 using the built-in FreeRTOS library functions. I want to try the inits in a loop, with a short delay between attempts, and I want the watchdog to reset the ESP after say 5 seconds. N. xTicksToDelay: The amount of time, in tick periods, that the calling task should block. I tried RTU-master and RTU-slave example by slightly modifying them. 1. This guide also includes a comparison of vTaskDelay () function provided by FreeRTOS with different delay values in milliseconds. If you load the BT library the Wi-Fi is on. , integers, strings, and boolens). Hi, it's me again with more stupid questions. startTask(); while(!task. This is the second part of a series of ESP-IDF tutorials that I will complete as I learn stuff. cpp 📋 Copy to clipboard ⇓ Download. The TWDT is responsible for detecting instances of tasks running without yielding for a prolonged period. Also run each test at least twice, to detect nondeterministic/random effects. This library enables you to use Interrupt from Hardware Timers on an ESP32-based board. h> #include <sys/time. Espressif ESP32 Official Forum. Maybe you could use vTaskDelayUntil () to get you close. h) will allow you to busy-wait for a correct number of microseconds. 3 In the callback function of the Timer#1 start Timer #2 with the interval of 1 sec. In the past I've played around a little with Rust and long before I put together a few little projects with ESP32 controllers using the Arduino libraries. In the MRE below, the Consumer Task has a higher priority than the Producer Task. . Best practice task watchdog timer implementation: ESP32 & SIM800. The ESP32 does not reset now. In my test applications that don't use any sockets, this task literally only calls std::this_thread::yield () over and over. The constant portTICK_PERIOD_MS can be used to calculate real time from the tick rate - with the resolution of one tick period. Re: Task watchdog got triggered. This document describes using ESP-IDF with the ESP32 SoC. Basically I just want to run a task a given hertz (for example 50 Hz). Step 2: If i put the Oled and NTP code in the main loop function, all is well. August 15, 2022. Shizen February 21, 2023, 1:53am 5. To delete the timer when it is no longer needed, call esp_timer_delete (). But the documentation for xTaskCreatePinnedToCore () states: "Tasks must be implemented to never return (i. Even a simple loop causes it to crash: ELF file SHA256: 0000000000000000 Backtrace: 0x4008860c:0x3ffbf8f0 0x40088889:0x3ffbf910 0x401300bc. The power supply is a USB-A - AC adapter, 5V, 1A. The ESP32 development board comes with FreeRTOS firmware already installed on it which is supported by the Arduino IDE as well. The vTaskDelay() instruction pauses the task from which it is invoked, so in the case of Arduino, if I call delay() inside loop() it will pause most of the things. Internally, esp_timer uses a 64-bit hardware timer, where the implementation depends on the target. This is split into three stages: Port initialization of hardware and basic C runtime environment. [中文] Overview Optimizing execution speed is a key element of software performance. So how is it the main task will happily delete itself upon return, but. 1) Bug with IDF functions that internally call vTaskSuspendAll () The assert in vTaskDelay () checks to see if the uxSchedulerSuspended of the current core is set. I have ensured that this is the only task with priority 1. The data output looks like. Watchdog timer errors for loops for webserver on ESP32. I chose the ESP32 because of its 240MHz clock, but it still seems to be having trouble. 0 by Oleg Mazurov ). xTaskCreate (uploadToAWS, // Function that should be called "Upload to AWS", // Name of the task (for debugging) 1000, // Stack size (bytes) NULL. Steps to execute an interrupt in ESP32. It is a signaling process whereby a waiting task is signaled by another task to continue execution. I also used portTICK_RATE_MS but the speed didnt change . ESP-IDF uses FreeRTOS which is a real-time operating system. The RTOS task does not consume any CPU time when it is in the Blocked state. CircuitPython uses the asyncio library to support cooperative multitasking in CircuitPython, which includes the async and await language keywords. Declare a variable of type SemaphoreHandle_t to store the values of semaphore. ", ""); is added to the soundDoorbell () function then the following crash occurs. Not that an ESP32 dual core tutorial is bad, perhaps overtly advanced for. This function takes exactly the same arguments of the xTaskCreate and an. /* Blink without Delay Turns on and off a light emitting diode(LED) connected to a digital pin, without using the delay() function. This must not be confused with a human time scale of tens or hundreds of milliseconds or indeed, a couple. Two reasons why this is helpful. 1. My attempt at the code looks like this: ESP32CoreTaskTest_Class. Make sure that you are at version 1. Serial. Main Task (main) Task that simply calls app_main. Delay a task until a specified time. For a full example, refer to PlatformIO ESP-IDF ESP32 blink example. Esp freezes after 12 hours or 24 hours. An ESP32 Event Group is simply a collection of flag bits that can be set / reset. I would like to use the 2nd core on my ESP32. The files needed to utilize the Task Scheduler Library in your code are listed below and available in the code link at the end of this project: Task. input_delay_ns – Input delay from SCLK launch edge to. With a big disclaimer that there's. Example code: void Task1code( void * parameter ){ Serial. LAC timer is used for ESP32. @Whandall perhaps you can help out making this ESP32 task example more indicative of what ESP32 can do. 1-1 That FreeRTOS library is specifically written for use with boards that have an AVR architecture microcontroller. System initialization of software services and FreeRTOS. INCLUDE_vTaskDelayUntil must be defined as 1 for this function to be available. The Interrupt Watchdog is responsible for detecting instances where. The next running task is the task that has highest priority and is in Running state. The NodeMCU ESP32 is based on the Xtensa 32-bit LX6 dual-core microprocessor that embeds the FreeRTOS OS. attachInterrupt(GPIOPin, ISR, Mode); This function accepts three arguments: GPIOPin – sets the GPIO pin as the interrupt pin, which tells ESP32 which pin to monitor. 0/v3. delay( 0 ); do not reset WDT timer. It might not be very useful. github-actions bot changed the title ESP32 Watchdog timer limited to approximately 1 hour, fix herein ESP32 Watchdog timer limited to approximately 1 hour, fix herein (IDFGH-4847) Mar 1, 2021 Dazza0 self-assigned this Sep 23, 2021There are different solutions. so if the task is not yielding i. The esp32 is placed close to the AP. The CPU is executing at a constant processor clock rate. This means that other code can run at the same time without being interrupted by the LED code. Note: Suppose that we have 2 tasks: the low priority task and the high priority task. For a full example, refer to PlatformIO ESP-IDF ESP32 blink example. 1-1 That FreeRTOS library is specifically written for use with boards that have an AVR architecture microcontroller. The problem is no to pass control back to FreeRTOS but the handling of the watchdog in the eps-idf framework. Check this link for more details. If it is your first time working with this board it may be useful to get an overview of the microcontroller: General information about the ESP32 port. The Print stream is configured to the UART0 of the ESP32. ). ESP_PM_CPU_FREQ_MAX. For your WDT issue, I think it's better to change the priority of WDT task to be higher than that of the task you're monitoring. LAC timer is used for ESP32. (Note: don't forget to call this function, or it will lead to the watchdog restarting the ESP32). If the total is ~ 520kB, we can take the percentage. I dont have any problem to use delay function, I want to use delay while doing some other subroutine or task while delay is called and while reading yield function, i think of it as something that can run any subroutine or task while delay is in progress. ). Inside the DHT_Oled_task() we will first initialize the I2C interface. I'd shy away from millis() and use the ESP32's cycle count values. Certain things do go on while the delay () function is controlling the Atmega chip, however, because the delay function does not disable interrupts. After successful setup the timer will automatically start. When an interrupt occurs, the microcontroller will go through the following steps: The microcontroller will halt the current task and will store the address of the next instruction (Program Counter or PC) on the stack (lower byte first). Type ESP-IDF: New Project in the search bar and press enter. If you want the task to be cancellable in the queue but do not want to check the cancellation token nor throw an exception yourself, you need to use the approximated code with a cancellation token. h. For context I have set up a esp32 Json websocket server running on core 1 in the Loop (); function and I created a task with the. They are typically used as FIFOs (First In First Out) [1], meaning that. void delay(uint32_t ms){vTaskDelay(ms / portTICK_PERIOD_MS);} defined in packages/esp32/hardware/esp32/1. 5) nRF52 (tested on nRF52832). Overview. B. If we look at the esp-idf documentation about ESP32 WDT we can see that ESP32 comes with an interrupt watchdog and a task watchdog timer api. 2. Switch to “Standby” mode, when you are not executing any task, which will allow us to save energy. Board ESP32-WROVER-E Device Description DevKitC V4 Hardware Configuration pin_sclk = 18; pin_mosi = 23; pin_miso = 19; pin_dc = 21; Version v2. ESP32 Timer Example (Arduino) Let’s say we’d like to toggle an LED every 1 ms without using a delay that blocks the CPU and does much harm to the overall timing performance of your system. On ESP32, micros() takes about 150 cycles. I've run into a problem recently when working on a new project involving an ESP32 and a max43421e (USB Host). Also run each test at least twice, to detect nondeterministic/random effects. Hi, The thing with uS delays under software control is you need to clearly understanding you're tolerances. Light-sleep duration is chosen to wake up the chip before the nearest event. gfvalvo February 21, 2023, 1:44am 4. delay () is a blocking function. h" #include "esp_event_loop. 0. But as delay() suspended the controller, in real works, for multiple LED controlling, we use Timers/interrupts to control its On/Off time. tool-cmake. Less memory. It’s also one of the worst things. Every 1ms a timer interrupt fires and the scheduler jumps in and looks for the highest priority task that is able run. The arguments to this function are the following [1]:. After invoking the idle hooks, the idle task puts the CPU into "wait for interrupt state" ("waiti", similar to "wfi" in ARM CPUs). timeClient. If you REALLY need a delay, use ::delay(), but this will block the task and the scheduler. This. Each interrupt has a fixed priority, most (but not all) interrupts are connected to the interrupt matrix. 1. See note below. Re: performance power consumption in loop thread. @Power_Broker I understand this basic kind of delay and how millis function run inside the delay function. The async web server uses AsyncTCP, which uses its own task for event callbacks. Hi there! I'm currently trying to get started with Rust on ESP32 controllers. Yes. Then we select the prescaler to apply to the timer clock signal. 1. Each interrupt has a fixed priority, most (but not all) interrupts are connected to the interrupt matrix. Basically I just want to run a task a given hertz (for example 50 Hz). Inside the main () function, we will create the tasks. delayをtask定義の前に入れるか、削除で解決 タスク定義はできるだけ最後にした方がいいのかな。 マルチタスクの弊害が出てしまった。 今回でだいぶesp32のことを知れた。 おもしれぇやつだな、おめぇ. This leads to the second tangentially related problem. cung cấp thời gian chính xác. The function that is called from the task created above is a simple function as shown below. The next task in this project is to read the temperature that is going to be used to control the damper. The Interrupt Watchdog is responsible for detecting instances where. ) to perform the delay. Gotcha. h" #include "esp_deep_sleep. The closest solution to yours would be to create a semaphore that you attempt to take inside the task with a 100ms delay and that you give from ISR. h BaseType_t xTaskDelayUntil( TickType_t *pxPreviousWakeTime, const TickType_t xTimeIncrement ); INCLUDE_xTaskDelayUntil must be defined as 1 for this function to be available. Every once in a while it appears the vTaskDelete call ends up deleting or blocking the calling task as well. Device Description. Without the delay’s the outcome is the same. An alternative way to perform a task periodically is to count the time manually, and execute the right codes at the right moments. The next parameter 2048 is the memory allocated to the task in word (2 Bytes). 1 Demo - In this demo, we create 2 tasks: low priority task and high priority task. . These. Can you tell me whether this sort of modbus messaging makes any sense So I have ESP32 devices that are each assigned a serial number. These push buttons specifies the PWM value of motors and some constants. You're 95% of the way there. In the task print the task sized using something like this, log_i ( "fDoTheHumidityThing high watermark %d", uxTaskGetStackHighWaterMark ( NULL ) );. h" library, after the Wifi connection completed the task stay IDLE with a infinite loop of delays. I wrote the following sketch to try and confirm my understanding of how multitasking is handled. getfreeheap (something similar to this in the Arduino core). curr_pos; i<=stepper1. Example code can be found here. This means that the highest priority task that can run on a CPU will *always* be the task which runs on that CPU. . After you have uploaded your code to the development board, press its ENABLE button. esp_timer set of APIs provides one-shot and periodic timers, microsecond time resolution, and 64-bit range. Solution. 本範例主要是針對Arduino (ESP32)單晶片使用單核心情況下，往往因為delay指令，讓程式在執行過程中產生暫停或卡住，須等delay的時間過後，主程式才能繼續進行。. ESP32－delay関数（時間調整について）. To prove it, just upload a dead simple delay sketch and see if it works then. Then when the task wakes up it could check the RTC and delay a little longer as needed. void vTaskDelayUntil (TickType_t *const pxPreviousWakeTime, const TickType_t xTimeIncrement) ¶. delay(1); This will feed the watchdog timer without disabling it. h. The maximum amount of time the task should block waiting for an item to receive should the queue be empty at the time of the call. The next task in this project is to read the temperature that is going to be used to control the damper. Internally, esp_timer uses a 64-bit hardware timer. xTaskDelayUntil [Task Control] task. Always use RTOS based delay function. It's there to ensure that tasks (usually only idleTask) aren't unexpectedly starved. This function will return timer structure if configuration is successful. TASK_1 has prio 1. println(xPortGetCoreID()); for. The delay was originally inserted due to ledc updates not working if they are performed back-to-back. Kick them up to at least 2048 and try it. The timer can be started in one-shot mode or in periodic mode. Switch to “Standby” mode, when you are not executing any task, which will allow us to save energy. 3. The next running task is the task that has highest priority and is in Running state. vTaskDelay is no good for small mS delays. Improving Overall Speed ¶. 2. What's the reason or how can I get shorter delay when the smallest delay which I can use using assembler "nop" command gives me 0.