Espressif ESP32 Official Forum. Post by tankist » Thu Feb 10, 2022 7:08 am . esp32 GPIO interrupt latency. One way is to let the wifi driver setup the interrupt handler. ”. Depending on the project at hand I switch between two development environments: either ESP-IDF, running under Eclipse on Ubuntu 18. If the ISR for interrupt 0 is executing and interrupt 1 occurs, it will be held until interrupts are turned on again after I0 has finished. In particular, for ESP32-WROVER module, call rtc_gpio_isolate (GPIO_NUM_12) before entering deep sleep, to reduce deep sleep current. Arduino Interrupts Latency & Response Time. The following optimizations improve the execution of nearly all code, including boot times, throughput, latency, etc: Set CONFIG_ESPTOOLPY_FLASHFREQ to 80 MHz. Post by mTron47 » Fri Jul 13, 2018 3:39 pm . We even have the NMI free, in theory, that should 100% guarantee you interrupt latency. Now I have found the time to do it for myself and with the ESP32 and some other platforms. With wifi connected it tends to be on the higher side. I suspect the latency comes from the SDK, in the management of interrupt handlers. The IPC feature allows execution of a callback function on the target core in either a task context, or an interrupt context. Now I have found the time to do it for myself and with the ESP32 and some other platforms. Home; Quick links. As far as I know, ESP32 has no Schmitt trigger inputs, so what you get is the expected behaviour. We are using two external interrupts on the esp32, one interrupt is attached to core 1 (this is a high level interrupt on GPIO_NUM_35) and the other one is a low level interrupt which is tied to core 0 on GPIO_NUM_27. Plus we need to define an instance of this static variable. At 17uS, the esp32 responds to the event and sets an IO line to respond, which is too late. Interrupt latency on the ESP32 is a little higher than ESP8266, although there are also a lot of other variables which can effect interrupt timing. Pyboard) achieve much lower interrupt latency (few us) but prohibit memory allocation in interrupt handlers. When the timer finishes. The PIR Sensor acts as an source for the external interrupt. the AC module is powered by the 3V3 regulator of the ESP32 dev board. Post by jfmateos » Mon Nov 07, 2016 9:03 am . Extra latency depends on several factors, such as the CPU frequency, single/dual core mode,. Interrupt Latency Requirements Encoder requires low latency response to changes of the signals. Register; Logout; Contact us; Board index English Forum Explore General Discussion; Interrupt low Latency - again. 35uS, the master brings the line high. unsigned char enable_effect= 1 (saturation and hue enable)+. Post by bmakovecki ». An Operating system (OS) is nothing but a collection of system calls or functions which provides an interface between hardware and application programs. Reduce external interrupt latency. txt" below you can see some details. But I'd guess that it is impossible to read. At this point, the Interrupt Service Routine commonly known as ISR is called. Because there are more interrupt sources than interrupts, sometimes it makes sense to share an interrupt in multiple drivers. IRQ Startup latency. esp32 GPIO interrupt latency. Setting a bit and polling this bit in another task within an infinite loop is faster (2 us), but cannot be a real option, because this is waste of resources and prevents from deep sleep options. The operating voltage of this SoC is 3. Each interrupt has a programmable priority level. Depending on the project at hand I switch between two development environments:. d98151a. I would like to know the interrupt latency for an external pin interrupt in ESP32. It also takes 26uS to process the IRQ body, though I am using QueueSendfromISR in the. Calling a C function from an interrupt requires the CPU's context to be saved, and the call stack to be switch to that of the C ISR. Post by jfmateos » Mon Nov 07, 2016 9:03 am . Each interrupt has a fixed priority, most (but not all) interrupts are connected to the interrupt matrix. To make the static function work, it can only access static variables. and at T=9. Because there are more interrupt sources than interrupts, sometimes it makes sense to share an interrupt in multiple drivers. 35uS, the master brings the line high. The kernel addresses such use-cases by allowing interrupts with critical latency constraints to execute at a priority level that cannot be blocked by interrupt locking. In the Arduino IDE, we use a function called attachInterrupt () to set an interrupt on a pin by pin basis. Board index English Forum Discussion Forum ESP-IDF; Reduce external interrupt latency Writing into a queue in order to handle the interrupt in another task takes way too much time (about 13 us). On the ESP32, the Interrupt Allocation can route most interrupt sources to these interrupts via the interrupt mux. I highly recommend reading the project logs for more detail. Extra latency depends on a number of factors, such as the CPU frequency, single/dual core mode, whether or not frequency switch needs to be done. At 17uS, the esp32 responds to the event and sets an IO line to respond, which is too late. The following optimizations will improve the execution of nearly all code - including boot times, throughput, latency, etc: Set CONFIG_ESPTOOLPY_FLASHFREQ to 80 MHz. and it should be PubSubClient client (net); 1 Like. The wording they used in "ESP32 Technical Reference manual", Chapter 5. 2 posts • Page 1. I think there has been a little bit of progress, although not specifically for this purpose: the GPIO drivers have been optimized a bit so if you use the ESP-IDF API, your interrupt latency should be a bit lower (but not as low as using the bare metal), and ESP-IDF now allows you to have high-prio assembly interrupt handlers without having to. Create the function that will be executed when. Maximum extra latency is 40 us (when frequency scaling is. Normally, interrupts are written in C, but ESP-IDF allows high-priority interrupts to be written in assembly as well, resulting in very low interrupt latencies. esp32 GPIO interrupt latency. WiFive. At first, I thought the I2C was hanging in the ESP32 but I can see that the problem is. None of them is induced by the abort in your modified esp_timer_impl_set_alarm code. The only way you are going to get microsecond stable interrupt latency is to code for bare metal and roll your own operating system. Improving Overall Speed. Skip to content. Post by mTron47 » Fri Jul 13, 2018 3:39 pm . Interrupt low Latency - again. Interrupt latency on the ESP32 is a little higher than ESP8266, although there are also a lot of other variables which can effect interrupt timing. Hi, I am having trouble with the external interrupt latency being very inconsistent. However, if interrupts are disabled for lengthy times, either by your code or another library, Encoder may miss a change. So, make sure you have the ESP32 add-on installed in your. This process is generally time consuming (currently clocks in at approximately a few microseconds on the ESP32) and is not suited for High Level interrupts since they're. I would like to know the interrupt latency for an external pin interrupt in ESP32. Through oscillometer I found the interval between the pulse and spi cs signal was as much as 100~200 us, while this thread says the interrupt latency can be reduced to about 2 us. GPIO Interrupt Latency - once more. 4 GHz Wi-Fi® band as well as Bluetooth® 5. and at T=9. 115200 baud is possible. bmakovecki Posts: 4 Joined: Fri Nov 03, 2017 9:20 pm. This is useful for interrupts which need a guaranteed minimum execution latency, as flash write and erase operations can be slow (erases can take tens or hundreds of milliseconds to. The wording they used in "ESP32 Technical Reference manual", Chapter 5. Each interrupt has a fixed priority, most (but not all) interrupts are connected to the interrupt matrix. Top. I think there has been a little bit of progress, although not specifically for this purpose: the GPIO drivers have been optimized a bit so if you use the ESP-IDF API, your interrupt latency should be a bit lower (but not as low as using the bare metal), and ESP-IDF now allows you to have high-prio assembly. If you use a delay (5) inside the ISR, you will be blocking the processor for at least 5ms, which for a computer is a lot of time. After having issues with interrupt latency I've checked an older thread where it's described that interrupt latency with C is around 2us. The IPC feature allows execution of a callback function on the target core in either a task context, or an interrupt context. The command to put on power down the microcontroller is thisESP32 - Interrupt is triggering when I send a pulse through digital pin. A event handler is registered and can be called correctly, but the interrupt latency seems pretty unpridictable. Ideally, we would want this time to be less. For Cortex-M3/M4, the whole latency this process takes is 12 cycles. We’ll cover how to publish to a single field and how to publish to multiple fields. Post by mTron47 » Fri Jul 13, 2018 3:39 pm . Depending on the project at hand I switch between two development environments: either ESP-IDF, running under Eclipse on Ubuntu 18. ESP_igrr Posts: 2066 Joined: Tue Dec 01, 2015 8:37 am. It’s a measure for the response time of an interrupt and it’s desired to be as small as possible. GPIO Summary. It also takes 26uS to process the IRQ body, though I am using QueueSendfromISR in the. Post by go4retro » Thu Jan 10, 2019 6:26 am . 2 us (when the CPU frequency is 240 MHz and frequency scaling is not enabled). Alternatively, it may be enough to run the gpio_install_isr_service call on a task that is pinned to CPU1. tankist Posts: 5 Joined: Tue Feb 08, 2022 7:22 am. Let it be A8 pin for example! ( The LED Pin) Step4: Click On The Pin You Want To Configure As An External Interrupt Input. Skip to content . 2 (aditional saturation enable)+. Espressif ESP32 Official Forum. Timer callbacks are dispatched from a high-priority esp_timer task. The Full code Listing. (186) boot. The interrupt source is a GPIO that connects to pulse-per-second signal from a GPS module. I only have 1 interrupt setup to trigger on any edge and I am seeing anywhere from 2us to. 5 posts • Page 1 of 1. Each CPU has its own interrupt latency which is dictated by the. I would like to know the interrupt latency for an external pin interrupt in ESP32. Home; Quick links. The code in loop is simply to output to the user, and like with External Interrupts, loop can simply inspect the interrupts flag, and perform an action based on this as needed. Maximum voltage for low input is 0. Post by go4retro » Thu Jan 10, 2019 6:26 am . Setting a bit and polling this bit in another task within an infinite loop is faster (2 us), but cannot be a real option, because this is waste of resources and prevents from deep sleep options. I seem to remember recent ESP-IDF versions have some allowances to also run C high-level interrupts, but I don't have the details on that. The ESP32 is communicating with a PIC16 microcontroller through an I2C bus. A event handler is registered and can be called correctly, but the interrupt latency seems pretty unpridictable. Arduino PCINT (Pin Change Interrupts) by Khaled Magdy. esp32 GPIO interrupt latency. It also takes 26uS to process the IRQ body, though I am using QueueSendfromISR in the. Post by jfmateos » Mon Nov 07, 2016 9:03 am . It needs to save the current CPU registers, program counter. I'm using the following code: Code: Select all. Return. At 17uS, the esp32 responds to the event and sets an IO line to respond, which is too late. 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). Post by bmakovecki ». The IRQ must be subsequently enabled via irq_enable () before the interrupt handler begins servicing interrupts. Espressif IoT Development Framework. Skip to content. That needs 2 µs latency to start the waiting task RTOS_2 in core 0. In the attached "interrupt. Alternatively, it may be enough to run the gpio_install_isr_service call on a task that is pinned to CPU1. Extra latency depends on several factors, such as the CPU frequency, single/dual core mode,. As the e32 device, the esp32 have some sleep type, but for this test we are going to use Light sleep with GPIO wake up. How can I minimize latency and execution time for interrupt ? I register interrupt as: Code: Select all. Hi, I'm using a GPIO pin as a external interrupt, responding to negedge events. Apparently the expected interrupt latency is around 2 us; alternatively you can write your own high level interrupt handlers in assembler. Hi, I'm using a GPIO pin as a external interrupt, responding to negedge events. Unfortunately, interrupts on the ESP32 are a bit more complex than on an AVR (mostly because we need to do a bunch more context switching things, as well as the need to figure out what interrupt is triggered. It also takes 26uS to process the IRQ body, though I am using QueueSendfromISR in the. Example Software. A event handler is registered and can be called correctly, but the. Run UART Communication - Sending/receiving data. Setting a bit and polling this bit in another task within an infinite loop is faster (2 us), but cannot be a real option, because this is waste of resources and prevents from deep sleep options. Created by Espressif Systems, ESP32 is a low-cost, low-power system on a chip (SoC) series with Wi-Fi & dual-mode Bluetooth capabilities! The ESP32 family includes the chips ESP32-D0WDQ6 (and ESP32-D0WD), ESP32-D2WD, ESP32-S0WD, and the system in package (SiP) ESP32-PICO-D4. Because there are more interrupt sources than interrupts, sometimes it makes sense to share an interrupt in multiple drivers. I think there has been a little bit of progress, although not specifically for this purpose: the GPIO drivers have been optimized a bit so if you use the ESP-IDF API, your interrupt latency should be a bit lower (but not as low as using the bare metal), and ESP-IDF now allows you to have high-prio assembly. A event handler is registered and can be called correctly, but the. Setting a bit and polling this bit in another task within an infinite loop is faster (2 us), but cannot be a real option, because this is waste of resources and prevents from deep sleep options. 6. At 17uS, the esp32 responds to the event and sets an IO line to respond, which is too late. Post by ESP_igrr » Mon Nov 07, 2016 11:36 am . There are no native software interrupts in Arduino UNO (Atmega328p) microcontroller. RTOS task notifications can only be used when there is only one task that can be the recipient of the event. Interrupt latency on the ESP32 is in the order of microseconds, unfortunately; there's a fair amount of prologue going on. Top. ESP32-S3 GPIO interrupt latency is too high. 2 posts • Page 1 of 1. greetings sdk: IDF V4. First of all, the timer should be initialized by calling the function timer_init() and passing a structure. Interrupt Latency is the time when the interrupt was triggered to the time the event handler started execution. The esp_intr_alloc () abstraction exists to hide all these implementation details. The esp_intr_alloc () abstraction exists to hide all these. try Ethernet. I am seeing a similar issue as noted here:. Espressif ESP32 Official Forum. Module Connections. At 17uS, the esp32 responds to the event and sets an IO line to respond, which is too late. The arduino IDE completely abstracts the linking, interrupt tables and all that. Home; Quick links. The latency time is now 330 nsec (before 2,5 - 4,5 usec!) Usage of. Yes, but for filling a beaker I doubt a few microseconds will matter. Home; Quick links. within the loop, the WiFi connection just sits idle in the background. A driver can allocate an interrupt for a. I am seeing a similar issue as noted here:. I write the interrupt handler in assemble and register the interrupt in app_main with priority level 5. 1 Answer. This is double the 40 MHz default value and doubles the speed at which code is loaded or executed from flash. esp32: PRO CPU has been reset by WDT. The PLIC adds another 3 cycles from an external interrupt source. This is useful for interrupts which need a guaranteed minimum execution latency, as flash write and erase operations can be slow (erases can take tens or hundreds of milliseconds to. In the attached "interrupt. Writing interrupt handlers. According to the fe310-g002 manual, the interrupt latency of the core is 4 cycles from receiving the interrupt and including the fetch of the first instruction of the handler. Each interrupt has a programmable priority level. INUM_GPIO (4) is the index for a GPIO interrupt, and this bit will be set in INTERRUPT if a GPIO interrupt has occured. Writing into a queue in order to handle the interrupt in another task takes way too much time (about 13 us). I have one task at each core. static uint32_t lasthandshaketime; uint32_t. 2 posts • Page 1 of 1. If you're seeing significantly higher latencies, consider skipping Arduino - I'm not sure that the GPIO library there is oriented for performance. Now I have found the time to do it for myself and with the ESP32 and some other platforms. The GPIO_INT_* flags are used to specify how input GPIO pins will trigger interrupts. One way to get around this is to write a high-level interrupt in assembly, but that is non-trivial and I don't know if the Arduino environment supports it. There are actually SEI & CLI assembly instructions in the instruction set of Arduino’s. GPIO Interrupt Latency - once more. Post by tankist » Thu Feb 10, 2022 7:08 am . That means we connect the output of PIR sensor with the GPIO pin of ESP32 and ESP8266. Hi, I'm using a GPIO pin as a external interrupt, responding to negedge events. Post by jeromeh » Sun Feb 05, 2017 8:31 am . 2 posts • Page 1 of 1. It has 22 programmable GPIOs with support for ADC, SPI, UART, I2C, I2S, RMT, TWAI, and PWM. Through oscillometer I found the interval between the pulse and spi cs signal was as much as 100~200 us, while this thread says the interrupt latency can be reduced to about 2 us. Closed tannewt pushed a commit to tannewt/circuitpython that referenced this issue May 29, 2020. . and at T=9. That means this GPIO pin will trigger the interrupt whenever it will sense rising edge on its input. ESP32-C3 features four predefined power modes that not only enable developers to fulfill the requirements of various IoT application scenar- ios but also pass rigorous power consumption. The code is generated with this tool and modified for our test project requirements. Here is the source to show superfast interaction: External interrupt detected by task Core1 --300ns--> RTOS_2 (core 0) reacts. begin (115200); Serial. The syntax looks like below. And it has ability to lock and load lines which is useful to create SW breakpoints in Flash and have ability to minimize interrupt latency; Interrupt Controller: Highest priority interrupt has a specific register set to minimize interrupt latency; Sub priorities and Multiple priorities for each vector; Fully programmable interrupt controller is. After having issues with interrupt latency I've checked an older thread where it's described that interrupt latency with C is around 2us. Interrupt low Latency - again. Interrupt latency on the ESP32 is in the order of microseconds, unfortunately; there's a fair amount of prologue going on. The esp_intr_alloc () abstraction exists to hide all these. I will focus on describing how to refactor a. I have a precision pulse flow meter connected onto pin D4 of my ESP32 and am programming in the Arduino IDE environment. The later versions of esp-idf actually have hooks so you don't need to go about messing in idf itself if you want to use high-level interrupts in your program. mcpwm_isr_register (MCPWM_UNIT_0, isr_handler, NULL, ESP_INTR_FLAG_IRAM, NULL ); in interrupt I have simple float operation as : Code: Select all. All transactions must be handled by the CPU, which means that the transfers and responses are not real-time, and there might be noticeable latency. uint32_t mcpwm_intr_status = MCPWM [MCPWM_UNIT_0. Because there are more interrupt sources than. In this case, the IO_MUX is used to connect these pads directly to the peripheral. You can also test that your interrupt handler is running on core 1 by calling this from it. esp32 GPIO interrupt latency. You need to make sure it's already there. If using interrupts with multiple modules, since they are open drain they can be tied together if a single interrupt back to the MCU is desired. FAQ; Forum. Each interrupt has a fixed priority, most (but not all) interrupts are connected to the interrupt matrix. IRQ Startup latency. Choose the board, COM port, hold down the BOOT button, click upload and keep your finger on the BOOT button pressed. In this last example project, we’ll test multiple Arduino Timer Interrupts. Now I have found the time to do it for myself and with the ESP32 and some other platforms. 35uS, the master brings the line high. Register; Logout; Contact us; Board index English Forum Explore General Discussion; Interrupt low Latency - again. I explain it better, physically the edge of the signal and the callback execution has a delay of 200us between them. IRQ Startup latency. Skip to content . Espressif ESP32 Official Forum. Improving Overall Speed. tool-cmake. An esp32 can do the job but is overkill and will be adding a complexity you do not need when learning C. esp32 GPIO interrupt latency. Post by FL0WL0W » Mon Sep 06, 2021 12:00 pm . The esp_intr_alloc () abstraction exists to hide all these implementation details. The objective of this esp32 arduino tutorial is to explain how to handle external interrupts using the ESP32 and the Arduino core. The ESP32 has two cores, with 32 interrupts each. Extra. esp32 GPIO interrupt latency. I would like to know the interrupt latency for an external pin interrupt in ESP32. When using the ESP32 with the Arduino IDE, the default I2C pins are: GPIO 21 (SDA) GPIO 22 (SCL) If you want to use other pins when using the wire library, you just need to call:. Application Controlled Deferred Interrupt Handling Application controlled deferred interrupt handling is so called because each interrupt that uses this method executes in the context of a task created by the application writer. Espressif ESP32. Through oscillometer I found the interval between the pulse and spi cs signal was as much as 100~200 us, while this thread says the interrupt latency can be reduced to about 2 us. There the latency varies between 4us and 38us. To enable pin change interrupt on a pin, we’ll need to manipulate the PCICR register: The last three bits of this register are control bits for enabling a PCINT group. greetings sdk: IDF V4. Imagine now that we have an interrupt being fired when the signal goes low to high. Postby jeromeh » Sun Feb 05, 2017 8:31 am. For some reason, the traceback for case C could not be decoded by EspExceptionDecoder. g. I am seeing a similar issue as noted here:. ) What you may be running into is that when himem. Postby Xtensa2C » Sun May 31, 2020 9:56 am. Each interrupt has a fixed priority, most (but not all) interrupts are connected to the interrupt matrix. Follow 3 min read · Feb 8, 2022 1 A deep dive into the ESP32, the IDF and docs, hoping it can perform better. As the clock is directly on the bus, the speed of the ESP32 is critical - and more importantly - how quick can the ESP32 get an interrupt and store the address latch and then serve the data. Post by jfmateos » Mon Nov 07, 2016 9:03 am . However, it is possible to minimize this latency by using advanced parameters. The latency and jitter you can expect from a connection to an ESP32 depends heavily on the availability of free WiFi ether on the chosen channel. IRQ Startup latency. esp32 GPIO interrupt latency. And it’s usually expressed in CPU clock cycles or time (in μs or ns). The program below measures ESP-32 interrupt delay. After having issues with interrupt latency I've checked an older thread where it's described that interrupt. The ESP32-S2 chip features 43 physical GPIO pins (GPIO0 ~ GPIO21 and GPIO26 ~ GPIO46). Re: Critical attention to GPIO interrupts. As opposed to dedicated slaves, CPU-based SPI Devices have a limited number of pre-defined registers. ESP8266EX and ESP32 are some of our products. Setting a bit and polling this bit in another task within an infinite loop is faster (2 us), but cannot be a real option, because this is waste of resources and prevents from deep sleep options. Post by bmakovecki ». This is double the 40 MHz default value and doubles the speed at which code is loaded or executed from flash. 04 in a VirtualBox. 2 us (when the CPU frequency is 240 MHz and frequency scaling is not enabled). I'm trying to implement a high level interrupt to reduce the interrupt latency and jitter. Here is the source to show superfast interaction: External interrupt detected by task Core1 --300ns--> RTOS_2 (core 0) reacts. Espressif ESP32 Official Forum. Transmitter code. Andreas’s test method uses the ESP32 SDK via Arduino IDE. Skip to content. We can enable interrupt on any of these GPIO pins by attaching them to a corresponding ISR. As shown on the oscilloscope screenshot below, why is the interrupt triggered twice ? The issue is the same if I use different GPIO pins for the interrupt and gate. Top. Thus to create an interrupt on a pin, you must : Assign a pin to detect the interrupt attachInterrupt () attachInterrupt(GPIOPin, function_ISR, Mode); With Mode , the detection mode can be LOW , HIGH , RISING , FALLING or CHANGE. Choose the board, COM port, hold down the BOOT button, click upload and keep your finger on the BOOT button pressed. One way to get around this is to write a high-level interrupt in assembly, but that is non-trivial and I don't know if the Arduino environment supports it. bmakovecki Posts: 4 Joined: Fri Nov 03, 2017 9:20 pm. I use an ADPS-9960 for gesture control which triggers an external interrupt. Writing into a queue in order to handle the interrupt in another task takes way too much time (about 13 us). 2 posts • Page 1 of 1. Post by ESP_Sprite » Sun Nov 18, 2018 3:11 am . Reading the registers/state of another core. There are plenty of cases where low and consistent interrupt latency is important even when overall performance is not needed; an example would be building an AC dimmer using a zero-cross detector and a triac. 25VDD and the minimum voltage for the high input os 0. o. Overview. It also takes 26uS to process the IRQ body, though I am using QueueSendfromISR in the. Timer callbacks are dispatched directly from the timer interrupt handler. 35uS, the master brings the line high. Board index English Forum Discussion Forum ESP-IDF; Reduce external interrupt latency. And sei() function is similar to interrupts() function. ESP32 external interrupt latency. we are doing some stuff with an external RF transceiver and need to respond to its interrupts as fast as (technically) possible. It also takes 26uS to process the IRQ body, though I am using QueueSendfromISR in the. This condition is however met in the majority of real world use cases, such as an interrupt unblocking a task that will process the data received by the interrupt. Espressif ESP32 Official Forum. Espressif ESP32 Official Forum. I write the interrupt handler in assemble and register the interrupt in app_main with priority level 5. Espressif ESP32 Official Forum. IRQ Startup latency. For this tutorial we’ll program the ESP32 using the Arduino core. The ESP32 has two cores, with 32 interrupts each. An stm32 is "worse" in a sense that you can easily use the arduino IDE to work with esp32, but it is different with stm chips. I think there has been a little bit of progress, although not specifically for this purpose: the GPIO drivers have been optimized a bit so if you use the ESP-IDF API, your interrupt latency should be a bit lower (but not as low as using the bare metal), and ESP-IDF now allows you to have high-prio assembly. begin. Use this function if an RTC IO needs to be disconnected from internal circuits in deep sleep, to minimize leakage current. I am seeing a similar issue as noted here:. Re: External Interrupt Latency. g. Optimization efforts should be targeted at these. So my next step is to call an interrupt in assembly which required to use ESP32's higher priority levels. In ESP-NOW, application data is encapsulated in a vendor-specific action frame and then transmitted from one Wi-Fi device to another without connection. Hi guys, I am implementing an interrupt handler for reception of data through the UART of the ESP32. This routine initializes an interrupt handler for an IRQ. Each interrupt has a fixed priority, most (but not all) interrupts are connected to the interrupt matrix. Interrupt latency on the ESP32 is in the order of microseconds, unfortunately; there's a fair amount of prologue going on. Do you need speedy reactions and simple coding? Then, interrupts are a good thing to use. The time between each pulse is anything. Writing into a queue in order to handle the interrupt in another task takes way too much time (about 13 us). Interrupt low Latency - again. I'm detecting another delay related with the GPIO interrupts from ESP32. Learn how to use ESP32 PWM with Arduino IDE: ESP32 PWM with Arduino IDE. tankist Posts: 5 Joined: Tue Feb 08, 2022 7:22 am. ESP32 external interrupt latency. These ISRs are designed for performance-critical interrupt handling and do not go through common interrupt handling code.