Triggy - Multi-function Sensor Node

A smart sensor Node to trigger an action on a smartphone each time a physical change is detected (temperature, displacement, click...)

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This multi-function connected device will trigger the action of your choice on a smartphone or tablet when a physical event occurs, based on predefined rules. No external server required, only a bluetooth LE link with the phone to provide a solution for an incredible number of everyday life situations.

An Android application is used to find Nodes and to create rules between triggering events and actions to be performed. Also when using it with IFTTT or a cloud connection, the possibilities become even wider: home automation, remote notifications, cloud automation... As an action, an HTTP webhook can be sent via WiFi and so interact with your Raspberry Pi or ESP8266 projects.

As only an Android device is required with the Triggy Nodes, this solution is very simple and cheap. Also it is ultra-low power and small, enabling a lot of use cases.

Basically, Triggy aims to offer a solution to many situations, using a small board (the Node) as a smartphone or tablet companion. The Node senses the environment and automatically triggers actions based on physical events, paving the way to numerous usage scenarios. A Triggy Node can detect an event such as: this door is opening, the temperature in the fridge goes above x degrees, someone pushed the button, etc... Then a fully customizable rule allows to decide what to do: generate a notification on the phone, play a ringtone, or a lot more. An advantage over other solutions is that no external server or account creation is required!

Among possible actions, one can trigger an IFTTT recipe and as a result choose an action among a very large choice. Triggy can be used as a component of a home automation system (http webhooks are parts of the possible actions), however not limited to home applications.

Here below are some examples of situations where Triggy can be used, based on tested rules:

Some actions are local to the device connected to a Node (notification , play a sound/ringtone, put the device on vibrate...), others are available through IFTTT. Cloud connection + IFTTT = extended possibilities.

Video showing an exampIe of IFTTT recipe creation and action triggering:


Today one can easily buy and install a more or less expensive smart home solution. Some of them allows a connection to the cloud, others also support the IFTTT service. With Triggy, we want to enable new possibilities, new usages. Hereafter the key points that have guided this project:

  1. Low investment required
  2. Most of home automation solutions use a hub, a box to centralize and connect the different parts of the system (sensors, actuators ...) The price of that hub makes the whole solution generally expensive. Using an already owned, a spare or second-hand smartphone or tablet, the hardware cost of a Triggy solution will be far lower. With one Triggy board and a smartphone, it is already possible to do wonderful things. Additionally buy a WiFi smart plug, smart light or any available smart actuator that supports IFTTT, and you can easily do home automation. Low cost and easy to use!

  3. Small form factor and low power
  4. These two constraints go hand in hand, because the size of a WiFi-connected sensor (no hub required) is generally imposed by the size of the battery required to operate it for a decent duration. Components choices and efforts to reduce the power consumption of the Triggy Node allow now to make it work on a coin-cell battery (CR2032) with at least a year of battery life. The board dimensions have been decreased down to 25mm x 25mm, which allows to stick it almost everywhere (mailbox flap, cat flap, small objects ...) while being discreet. Existing sensors, such as a movement detector, working without a hub or gateway (WiFi) are a lot bigger than this, due to the WiFi peak consumption.

  5. Open standard
  6. Bluetooth Low Energy is used for the communication between the Triggy board and the smartphone. This protocol is both publicly accessible and low power. BLE GATT servers (such as Triggy) expose a standard data structure, allowing to use it with other applications. Another advantage is a seamless integration of Triggy with any smart home solution compatible with IFTTT. It can work also with the numerous WiFi actuators (IFTTT compatible), without being bound to a solution manufacturer that uses a proprietary protocol.

  7. Extensible and scalable
  8. The Triggy board embeds few sensors (displacement, temperature, proximity to the smartphone, push-button) and still allows to create a significant number of useful usages. But we also want to allow easy connection of expansion boards...

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Paper case - front .pdf

Printable paper enclosure for the board - front side

Adobe Portable Document Format - 522.26 kB - 09/07/2016 at 20:26


Paper case - back.pdf

Printable paper enclosure for the board - back side

Adobe Portable Document Format - 102.63 kB - 09/07/2016 at 20:26



nRF52832 official datasheet

Adobe Portable Document Format - 5.86 MB - 08/23/2016 at 12:05


  • 1 × Nordic nRF52832 Bluetooth LE Microcontroller
  • 1 × NXP MAG3110 Magnetometer
  • 1 × Johanson 2450AT43A100 SMD 2.4 GHz chip antenna
  • 1 × Murata XRCGB32M000F2P00R0 Crystal 32 MHz
  • 1 × AVX ST3215SB32768E0HSZB1 32.768 kHz crystal

View all 10 components

  • Board version 0.3: LSM303D replaced

    Vinch11/23/2017 at 21:01 0 comments

    This is the new (last ?) revision of the Triggy Node board. The main motivation for this new board is the unavailibility of the accelerometer/magnetometer, the LSM303D. Since few months, this component was unavailable from any distributor. Lastly it was stated as: "end of life".

    Consequently, I had to find another magnetometer sensor component. The LIS3MDL would have been fine, but this part was also unavailable. So I decided to use a popular magnetometer among makers: the MAG3110 from NXP. It is not very expensive and easy to use. Also the package ( QFN) is far easier to solder than the LGA of the LSM303D. The only drawback I see is a slightly higher power consumption in running mode and 2 uA (instead of 1 uA) in standby.

    Of course, the capacitors around the magnetometer have been replaced to match the reference design provided in the datasheet. And lastly, the MAG3110 is no longer powered directly by the battery, but instead through a GPIO of the MCU. This allows to save the 2 uA when not using the magnetometer. The rest of the board remained unchanged.

    After having updated the firmware, the new sensor is working perfectly.

  • 3D Printed Enclosure

    Vinch08/15/2017 at 21:12 0 comments

    It's a new step for the Triggy project: a decent custom enclosure for the board. This plastic enclosure replaces the previous paper-made enclosure. It's less customizable and a bit more expensive but far more robust and gives a finished look. The Triggy Tag can also be safely let outside, e.g. for rain sensing or in the pocket.

    This enclosure is the result of several (a lot of) iterations with my personal FDM 3D printer. I used only PLA material for this prototype. The last version (on the pictures below) has been obtained on an SLA printer.

    The final enclosure, in black and white versionsEnclosure is made of two parts. Internal faces viewThe enclosure with the board inside

  • Triggy board v0.2

    Vinch05/09/2017 at 20:02 0 comments

    Hello everybody,

    I made a new version of the Triggy board and I've just populated it with the parts (no change on the part list). Everything seems OK with this new board, in particular the antenna matching which provides correct output power.

    Here are the changes versus the v0.1:

    - Smaller PCB with corners cut: this new form factor will allow using a more interesting enclosure shape without increasing its size (more information in a new coming log).

    - NFC2 pin no longer used as external board GND pin. The NFCx pins of the nRF52832 can be used as GPIOs, but the operation requires to flash some specific bits. Consequently it's easier to use other free pins.

    - The two sensors on the external board now have separate GND pins.

    - The references of the 32 MHz and 32 kHz crystal have been changed. Their load capacitance being different, I also have changed the associated capacitors.

    That's all for now. The github now contains this v0.2 board.

  • Some news

    Vinch12/13/2016 at 20:17 0 comments

    Since the decision to create rules directly on the Triggy Hub app, there is a lot of work to do before making everything work. This is a complete new screen to create, and this will take time. The good news: this way of mapping events and actions will improve a lot the usability of the system. Triggering local actions avoids the internet connection requirement while enabling more low-latency automation.

    An additional local action I though about is an emulation of a keyboard press. Many applications have hotkeys that can be activated with a physical keyboard. Here we can simply create a rule to emulate any keyboard press. A typical application would be to take a picture from the Android camera app when clicking the triggy module button.

  • Android app changes

    Vinch11/12/2016 at 08:37 0 comments

    Triggy Hub Android application is being heavily modified to enrich the possiblities. I wanted to make the system less dependent on IFTTT, for those who don't want to use this service. In fact, most of the time the user wants to be informed of an event (when a door opens, when it rains, when the temperature goes too low etc ...) This can be done with a notification or a kind of alarm. Moreover, notifications could be pushed to other devices with third party applications.

    So now it will be possible to create rules (local, not IFTTT) to run on the Android device. When an event is detected, one could decide to send a notification, play a sound, mute/unmute the phone, turn on/off the WiFi (any other idea ?) All this without internet connection required, but of course the phone must be in the BLE range of the Triggy module which generates the event.

  • First demo in real conditions

    Vinch10/10/2016 at 21:48 0 comments

    It's here now: a video showing Triggy in action through two IFTTT recipes. I also give instructions on how to create a recipe on The prototype is functional for a while now, but it doesn't have all features. After many trials of different video editors, I chose VSDC free video editor. I've found it both easy to use and powerful, at least perfect for what I wanted to do.

  • New Recipes Collection

    Vinch09/29/2016 at 20:29 0 comments

    The firmware and Android app will soon be functional, but before showing a video with IFTTT in action, here are some new recipes with Triggy as the source of the events.

    Simply stick a module on the cat flap. When it moves, a notification is sent. You can also record the time of all these movements directly on a cloud service of your choice.

    With Triggy and Manything app, the camera of a spare phone will start recording a video if someone opens unexpectedly a cupboard or a drawer. Who put his nose in your stuff?

    Never forget to close a door or a window for the night. Every day at 10 pm (for example), you will receive a notification if the "open" position is detected.

    With a module stuck on your guitar, you can automatically inform your friends on Twitter or other social network that you start playing, as the displacement is detected.

    If your car is moved in the street, you could know it instantly, even if far away. Just let the connected Android device in the car too.

    You may want to know when an icebox with your picnic inside is heating up, indicating that it's time for lunch...

  • DIY enclosure

    Vinch09/07/2016 at 20:21 0 comments

    Now that the prototype board is fully functional, I decided to create a nice looking enclosure for it. Of course, 3D printers are the most appropriate tool for this purpose, but I have no access to a 3D printer and also I've never used one. I can only spend a limited amount of time for it, so the best solution I found, for now, is to make it with cardboard paper. The dimensions of the board are small enough to obtain a quite strong enclosure even with paper.

    My experimentations showed that a paper of 270 g/m2 is enough, and still can be used with most inkjet printers.

    This is the equipment used and the result obtained once printed and cut

    I used the following equipment, in addition to an inkjet printer:

    • An A4, 270 mg/m2 paper sheet
    • An iron ruler
    • A box cutter
    • Wood glue

    The result

    The enclosure once folded and glued

    The triggy board in its box

    I've put the printable pdf files of the enclosure (front and back) in the files list. It has correct sizing for A4 paper.

  • IFTTT Recipes with Expansion Board

    Vinch08/20/2016 at 12:06 0 comments

    The first expansion board built for Triggy (see first project log) adds the rain/water and ambient light sensors. This board further extends the possibilities and service provided by the system. See hereafter few IFTTT Recipes made possible.

    As soon as the first drop of rain is detected, receive an SMS reminding you to close the roof windows or to pick up the clothes drying outside.

    You may have a tap leaking so slowly that you cannot keep watching it. Use Triggy to log any drop falling.

    It's preferable to irrigate the garden once the sun is setting down, but the real time change every day. Triggy and a smart irrigation system can do the job.

    For the romantics, Triggy can warn you when the sun starts to go down.

  • First Demonstration Video

    Vinch08/16/2016 at 20:59 0 comments

    Here is a video showing the Triggy device in action, connected to the Android application running on a nexus 7 tablet. The goal of the video is to show the movement detection and how the displacements are logged into the app. Note that the application is the part of the project which will evolve the most. An other video showing actions triggering through IFTTT will be done later, once all this is more mature.

View all 13 project logs

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Adam Fabio wrote 09/30/2016 at 00:02 point

Hey [Vinch]! Triggy is a featured project on the Hackaday front page! Congrats!

  Are you sure? yes | no

Vinch wrote 09/30/2016 at 07:37 point

Wow, that's great! Thanks a lot for the information.

  Are you sure? yes | no

Vinch wrote 09/06/2016 at 16:15 point

Hi Francois. Thanks for your interest and, by the way, thanks to all followers of this project! As of today, I managed to trigger IFTTT actions from the Android app, using a dedicated function. The next step is to develop the part which makes the link between the information received from the board, in BLE, and the call to this function. I'll make a video once all this is working together.

  Are you sure? yes | no

Francois wrote 09/05/2016 at 19:28 point

Hello. Nice project! There is a great potential for this affordable iot solution. But have you been able to actually make it work in real condition and trigger an IFTTT action? 

  Are you sure? yes | no

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