ESP32 with PIR Motion Sensor using Interrupts and Timers

For complete project details (schematics + source code), visit ► randomnerdtutorials.com/esp32...
This tutorial shows how to detect motion with the ESP32 using a PIR motion sensor. In this example, when motion is detected (an interrupt is triggered), the ESP32 starts a timer and turns an LED on for a predefined number of seconds. When the timer finishes counting down, the LED is automatically turned off.
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[@RuiSantosdotme]

You can find the complete project details (schematics + source code) on my blog ► randomnerdtutorials.com/esp32-pir-motion-sensor-interrupts-timers/

[@bgable7707]

EXCELLENT as always! I obviously had viewed this video in the past because the "thumps-up" was highlighted. Yet, watching it another time, helped solidify ISR's again. Your walking through the code line by line, explaining clearly the components use and their value brings these all together.

[@bobapthorpe]

I believe the variables startTimer and lastTrigger should specified as volatile since they are updated in the ISR. Also, you probably shouldn't call Serial.println() in the ISR; I understand you're doing it for the purpose of illustration, but in production code you want the the ISR to execute extremely quickly with as few side effects as possible. Otherwise this is a good, straighttforward example of how to use external interrupts; thanks for posting it.

[@aprenderinvestirpt]

Boas rui, estou a pensar utilizar esse sensor (PIR) com um esp-01 mas preciso que seja com bateria. Que bateria/pilhas aconselhas e como fazias o circuito de modo a que durasse mais ou menos 4-6 meses ou ate mesmo um ano ? (Estando em deepsleep)

[@davebeckham5429]

Excellent information. Thanks, Rui.

[@RuiSantosdotme]

Thanks! I'm glad you found it helpful!

[@alexmorales1997]

VERY VERY VERY USEFUL, I RLY LIKED IT!!!!

[@eriklaken1025]

Perfect, thank you.

[@alessandromaltese7578]

Thank you very much :D!!
I dont know but when the pir triggered and the LED turned on and again off, it takes to much time, until the pir detects again some motion. How can I change it?

[@MeinElektronikHobby]

... thanks for more information about the ESP family.

[@RuiSantosdotme]

You're welcome! Thanks for watching

[@reiniervanderbrugge5023]

Hi i have used your sketch and tutorial and it works perfect with one pir sensor.... but i want to use 3 pirsensors to activate a relay do you know how this can be done?

[@markroles7304]

If you are having the motionSensor pin configured as a pullup, how will then the interrupt ever catch a rising signal since it will always be high then?

[@hafzamhasan8532]

can i use the same esp32 to add in servo motor in ur other tutorial, ? how ?

[@EricOnYouTube]

Woohoo. It works! :) Thanks. I put mine on G13, though.

[@gibo588]

You can also use Ticker() library which works with millis() non blocking.

[@vigatex]

Hi,
Can the PIR sensor as a wake up input to a board in deep sleep please?

[@Smart3DPT]

Olá boa noite com um esp consigo accionar um servo 9g através do movimento?

[@aman5862]

How can we send the time duration the light is on when sensed by pir on some cloud or Google sheet?

[@norsuhaila4188]

Can i know how the wires are installed between nodes with pir

[@mrdanker6756]

ESP32 actually uses freeRTOS (your code runs within it), which handles threading & tasks. You can split code up into different tasks on the same core, and use delay, only having it affect one task, while the others continue to run

[@simonmay9039]

Yes, the Arduino framework wrapped around the ESP32 + ESP-IDF maps the Arduino delay() function into a call to the FreeRTOS function vTaskDelay(). This is non-blocking, ie it gives the time taken by the delay() back to FreeRTOS for it to give to other tasks.

[@eduardomanusse2904]

excellent

[@quaternion-pi]

Great tutorial. What happens if an interrupt is called while the program is executing in the interrupt function? Does it interrupt the interrupt function?

[@RuiSantosdotme]

Thanks! When using interrupt functions, you should try to keep what they do as simple as possible (they should be executed very quickly). If an interrupt is triggered while it's still running the interrupt function, it should run it again. (Note that this PIR motion sensor holds the state HIGH for a couple of milliseconds/seconds, so it's unlikely to trigger the interrupt function too quickly)

[@quaternion-pi]

Thanks, was just wondering if Serial.println() statements should be avoided in interrupt functions - or do they execute quickly enough. Love your informative videos.

[@RuiSantosdotme]

Yes, they should execute fast enough. So, you can have the Serial.println() statement during your tests/debugging, but for a final project I recommend always deleting all the unnecessary Serial.println commands.

[@sarjananganggur5546]

Apakah anda bisa membantu saya untuk mengkoneksikan sensor pir ke database mysql

[@Techonsapevole]

Thanks, can you wake up the ESP in deep sleep via PIR ? Can you provide an example?

[@GnobarEl]

Thats a good question!

[@amelliamendel2227]

can you wake it from sleep when motion is detected?

[@sahilmansoori3511]

Can I connect this sensor with any other ESP32?

[@chinmayih.k.3370]

I have COM3 port
And I can open serial monitor
What to do to open COM4 monitor

[@barbarasales1745]

Rui o meu não está a dar... ajuda-nos

[@isro_iuac]

code error 🙏

[@intheshell35ify]

Lets not block code, lets poll!!!! Huh?