PART 2 ESPNOW – The Ultimate DIY Home Security System – ESP8266 (trigBoard) + 4G LTE Modem

PART 2 ESPNOW – The Ultimate DIY Home Security System – ESP8266 (trigBoard) + 4G LTE Modem

All details found here on the project page:

Inspiration here:
Reference here:

Check out my Tindie store (trigBoard is available)

Thanks to all the Patrons for dropping a few bucks in the tip jar to help make these videos happen!


For inquiries or design services:



3D-GDad says:

First and foremost I want to say “Thank You” to Kevin Darrah. He listened to my special need for a device to help me to keep my wife safe.

At my request, he built a device from the Ultimate DIY Home Security System that would notify me anytime my front door was opened. He even tested the device using my network credentials prior to shipping. Once I received it, I went about setting it up and discovered I had made a mistake in the SSID I gave to Kevin. He quickly explained what I needed to do to make the changes to complete the setup. My router is an ARRIS SURFboard Wireless Cable Modem GW DOCSIS 3.0 SBG6900-AC.

He discovered my router was a model that didn’t play well with the trigBoard. He did some research and found two files that mentioned my router and the ESP8266, which is the brains of my device. My home network also includes a WiFi extender made by Netgear, configured as an Access Point. I adjusted the configuration to use the extender’s SSID and now my device works flawlessly every time my front door is opened.

I highly recommend that if you need assistance with any of Kevin’s electronic projects, he is extremely knowledgeable about what he builds and is very willing to support his products.

nikhil gaikwad says:

I like watching your videos. There is so much new and exciting things to learn from your videos. Thank you for your time to go through all this work to teach others. Very much appreciated.

Patrick Dorion says:

NodeMCU is a firmware, what you're referring to is an ESP12-E breakout…

I know you might not care, but when I want to find information about NodeMCU and all the results are about people who use the Arduino IDE, it pisses me off immensely….

Richard Kühne says:

What’s the range of ESP-NOW and is it able to build a mesh?

Istvan Zilizi says:

Hello, nice video, how about if the Triggerboard is not in the Gateway Unit range? I am looking for a MESH type network over ESPNow somehow connection to a MQTT server (Run on Own Raspberry Pi). Anyway great work!

MUDGEL says:

I live in what’s called a fringe reception area in Australia. Only 30klms from a city of 120k people but fringe nonetheless. Very costly @ min $15/month for LTE modem plan. If I lose power, which happens frequently then the cellular tower is also down so we don’t have phone or power or internet. Yep, it all goes so there’s no advantage in me having the independent cellular service. I’ll need to stick with my local wifi and internet connection at home. I think. Have to plan a bit more.

Wim Hoogervorst says:

Hey what's up KevinDarrah. Thanks for another inspiring video. Inspired by the Trigboard videos and the ESP-NOW video of Andreas Spiess I also made an ESP-NOW based door alarm, see
I forward the ESP-NOW messages via serial to a RPi running my home automation. Great that your stand-alone device is less dependent on other services.
I found out that the ESP-NOW communication is not always succesful, therefor I implemented a check whether the transfer of data was succesful and repeat the sending of the message for a short while. I do not see that in your code. Did you also find some problems with unreliable ESP-NOW communication?

Asger Vestbjerg says:

Impressive project as always
Thanks for sharing👍😀

Thierry Coton says:

What is basically missing for a true alarm system is a battery charger with load sharing so it can charge the battery and power the device at the same time and when main power is lost, it switches to battery. (like the Adafruit USB / DC / Solar Lithium Ion/Polymer charger – v2)

1CM69 says:

Great video thanks. I have been trialing the use of ESP-Now for a couple of months now with great success. I have a number of remote sensors (Masters) around my house which periodically send data back via ESP-Now to the Slave (Gateway) unit, which in turn shoots that data up to Thingspeak & Adafruit IO. I cobbled together the ESP-Now code from various sources as well as from the sources you mention.
I noticed in you video the way that you had to approach entering the mac addresses, in my code the mac address is entered exactly as it appears but just prefixing each of the pairs of digits with 0x.
At the moment I am still prototyping my project and using a DS3231 RTC on each remote sensor to more accurately control sensor reading times as well as a MOSFET latch to make power consumption zero for each sensor until the pulse from the SQW pin on the RTC powers the system up, even the RTC runs off it's own CR2032 battery until the alarm fires the SQW pulse.
Currently the sensor powers on, takes a reading, send this via ESP-Now to the Slave(Gateway) and then powers down in 220ms and consumes 90mA and this is once per hour.

Anyway, here is the basic stripped down code for ESP-Now communication between Sensor(Master) & Slave(Gateway), not including the RTC code:

Sensor –

Gateway –

Marvin Schneider says:

Is there battery protection on the board (over discharge)

louie8670095 says:

How about this project.
How to measures a 1000 water tank. With your phone. That measure where the water level is at one point

Ajay Sudhera says:

You can do this with Superhet Rx Tx Pair & attiny24 low power sleep mode mode.. Just use atmega on gsm sms side.
Good idea anyway.

Marc Paradis says:

Is the particule sleeping??

Daniel dias dornelles says:

Cube 12x12x12?

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