#176 BLE Human Presence Detector using an ESP32 (Tutorial, Arduino IDE)

Presence detectors/Sensors are essential for today’s home automation systems In earlier videos we looked at PIR and radar sensors, and we were even able to use Wi-Fi on our smartphones to sense our presence. All have advantages and disadvantages.
Today, we create the ultimate presence detector. And the best: It costs only a few dollars. How does this ultimate presence sensor work? Of course, with Bluetooth low energy and an ESP32.

- In this tutorial we will build a valuable BLE application which can solve a real problem
- We will learn how BLE advertising in detail works
- We will trace BLE packets to the last bit. I am sure this will help us in future projects
- We will connect the sensor to Mosquitto MQTT broker and to Node-Red on a Raspberry Pi

Links:

Please do not try to Email me or invite me on LinkedIn. These communication channels are reserved for my main job

[pinealservo]

A number of years ago I did a lot of research and experimenting on this kind of proximity tracking. It was fun but frustrating, because a number of technologies get really close to creating a great experience, but there were always fatal flaws.

The most success we had was with a very similar setup; we used small computers with Bluetooth 4.0 as tracking stations and recorded all the BLE advertisements received. We got a number of different fitness bands and such things (these were the first generation of FitBit and similar devices) and we had great success at measuring relative proximity. But we soon discovered that smart watches tended to either have MAC randomization (this is a capability of all BLE devices, but they don't all use it) enabled or wouldn't emit advertisements unless they were "awake". For a consumer device to track the owner's presence, it would really have to have its own "wearable" beacon and a pairing process that would allow paired trackers to recover the real MAC (this is also part of the BLE spec, I believe). More and more BLE devices will be un-trackable by a generic tracker due to either not transmitting advertisements all the time or using randomization--without randomizing, you could be tracked *anywhere* as your travel about, and that's a legitimate privacy concern that most companies are becoming wise to.

For a home-use hobby tracking system, there are a number of things that could work:
1. Find, as you did, some sort of wearable that always emits advertisements and doesn't use MAC randomization. As long as it still works, you're good, but if you upgrade to a newer version it probably won't be as trackable.
2. Find a source of cheap "beacon" type BLE devices--these are designed to be tracked by unauthenticated devices, mostly so apps can use them for local positioning in a retail environment. Some of these are designed to run for a year or more of constant beacon transmission on a coin cell. You'll have to make a wearable out of one of these yourself, and it won't do anything useful aside from turning your light on!
3. Write or install a smartphone app that will turn your smartphone into a "beacon" emulator. These apps are usually meant to help "beacon" app developers to test their apps without a bunch of actual beacon devices by instructing the smartphone to emit the advertisements that a beacon would, which would then be detectable by your tracker device. You have to remember to keep the app running if you want to be tracked, though.

[MaxintRD]

Hi Andreas, thank you for all the great videos in the past year. They were not only quite useful and interesting, but also very inspiring. I know making these videos took a lot of time and appreciate the effort you take to keep them interesting for your viewers. I wish you and your family all the best for the next year!

[nogmeerjan]

I think this starts to smell like a real new product. People detection combined with people recognition. Sounds like a alarm and home automation in one go.
I need to look at this more closely.
Thanks for all the great good hard work.

[franzmaurer]

Hi Andreas, I also wish you and all of your readers a happy New Year. Looking back, I realize how much I learned from your videos this last year! I am so grateful for that. Thanks!

[deangreenhough]

May I wish you and all 52k subscribers another wonderful year of Andreas Spiess videos. What a year it has been.

Thank you Andreas, wonderfully inspiring and always, worth the time watch over and over again.

Bless you for your kindness, hard work, precision and most of all for sharing and listening.

Your my electronics Grandfather for sure.

[BerndSchmitt-Martinique]

its always a pleasure to detect NEW FIELDS of application with your help and orientation. THANK YOU FOR YOUR HELP to so many makers.

[NikDoof]

I've actually created a similar system with a RPi with a USB Bluetooth device and have been planning to move this over to a dedicated ESP32 for a little more stability. Great video as always!

[LanceThumping]

I love all these Bluetooth videos. They've inspired me to try and put together a Bluetooth HID with an Esp32 to make a custom game controller. It's going to take awhile because it seems quite a bit more difficult than the heart rate monitor.

[klassichd]

Just a note regarding the radar sensors:
The radar sensors RCWL-0516, HB100 (10.525GHz), CDM324 (24GHz) are NOT interfered by the presence of an ESP8266 or ESP32. But they are interfered by a ripple on the supply chain.
I did not manage to supply them by a switch mode regulator - even with additional low pass filterimng. For my the best and easiest way is to use a dedicated 7805 linear(!) regulator just for the radar sensors and the amplifiers you need for the CDM324 or HB100.
After amplification you can feed the signal to an analog input of the ESP32 and perform a FFT to calculate the velocity. It works.

[alidollar]

You have guided and helped us all hobbyists in 2017 brilliantly, 2018 will surely be more amazing with all the new cool videos and ideas.
Happy New Year!

[ReevansElectro]

Brilliant as usual! Well scripted and I like the way you changed the order to give those who aren't enthused by the details a chance to ring up a view for your channel and also it give the rest of us who love the details a tantalizing view of what's to come. I wish you a very prosperous and exciting New Year.

[petermeiner]

auf deutsch, da persönlich an Dich!
Hallo Andreas, ich möchte mich herzlich bei Dir bedanken für dieses Jahr. Deine Videos sind mittlerweile für mich ein muss... der Sonntagmorgen hat eine neue Routine ;-) Auch deine Art und Weise ist immer sehr ansprechend, ich würde mir diesen Stil für einige andere Kanäle wünschen. Ich finde es fast unglaublich, wieviel Du produzierst! Kaum vorstellbar, wieviel Zeit Du hier investierst. Schade, dass ich es einfach (beruflich) nicht schaffe, mal bei Dir in der Nähe zu sein (das Bier steht ja noch aus!). Ich wünsche Dir und deiner Familie einen guten Rutsch in neue Jahr und ich freue mich schon darauf, was Du nächstes Jahr wieder hier (hoffentlich) machen wirst!

[asiw]

Another fantastic step forward. I have enjoyed the journey with you over the last 12 months and wish you health and happiness for 2018.

[korgmangeek]

Hi Andreas (great channel)

Only yesterday I learned some stuff about iBeacons (introduced in 2013). Some devices have sensonrs and transmit also some data.

Great battery life. With 2032 coin cell battery, I think more than 1 year.

[bricoarn]

Bonjour Andreas comme toujours une analyse de très bon niveau, des informations pertinentes aussi bien pour les débutants que les plus chevronnés... quel plaisir de vous suivre ! Excellentes fête de fin d'année pour vous, les vôtres et... votre chaîne YouTube bien cordialement

[onlyrgu]

You can theoretically covert ESP 32 to a Bluetooth sniffer by turning the wifi completely off. Please correct me if I'm wrong. Thank you for making my 2017 an IoT Year. Your videos inspired me to built lot of home automation projects (Got 20 + ESP boards already). Have Awesome new year and greetings from Electronic City, India

[keithofarns]

Thank you! This will become very useful for me. I might not upset my wife so much when forgetting about my shops lights.

[____________________________.x]

Thanks for the NodeRed info, I hadn’t heard of it before

[giorgosiotis]

Top of the top. Very usefull script and profetional presentation. Thank you . George from Athens Greece

[aDz]

Thanks Andreas, love your videos.
I just got myself an ESP32 and after a few hours of trying to get it setup (I stuffed up the Arduino IDE a few times) I got it working.
The problem I'm facing is that when it first starts it finds the device fine and send the message to MQTT but after that it wont find it again;

09:53:05.698 -> WiFi connected, IP address: 192.168.1.105
09:53:05.698 -> Connect to MQTT server...
09:53:05.698 -> Attempting MQTT connection...connected
Waiting for 60 seconds

09:54:06.922 -> BLE Scan
off
09:54:36.929 ->
09:54:36.929 -> BLE Scan
off
09:55:06.928 ->
09:55:06.928 -> BLE Scan
off

Is this how its suppose to work or is there a way to get it to re-send the message to MQTT every time it scans it?