Interacting with Particle Device using Slack and Natural Language Processing

Source Code


Natural Language Processing is becoming very popular these days. This is becoming one of the major method of user interaction. Apple Siri, Google Now, Amazon Echo, etc… all are examples of products that uses NLP.

There are many NLP APIs which we can used in our own applications, some of them are,, etc… Using these APIs you can process the natural language input in the form of text or audio. These APIs extract actions and intentions of the user and return something meaningful to our application. Before using these APIs to parse the input, you have to define what are the possible user expressions. For example when the user says “Turn on my bedroom light”, user intents to turn on the bedroom light. Here Turning On is the user intention and Bedroom Light is the device to turn on. In this example the word “on” and “bedroom” are the meaningful extractions from the user input. In case of “Turn off my living room light”, Turning Off is the user intention and Living Room is the location.

Here the words “on”, “off”, “bedroom”, “living room” are entities. To use these NLP APIs, we have to define these entities in all the possible user expressions. The results of all these APIs depends on how well you define the user expressions and entities.

Sample Application

The sample application is a simple Proof of Concept Home Automation Hub which can be controlled using Slack Messaging Platform. Particle Photon is used as a Home Automation hub. Three LEDs are connected to the photon that represents different room lights. A DHT sensor is connected to retrieve temperature and humidity of the room (please note that only one DHT is connected for the demo purpose). Another sensor attached is the Contact Sensor, which will send message to Slack when it is opened or closed. Using Slack messaging platform, a user can send messages to a channel to control the lights or retrieve the temperature and humidity values. An outgoing webhook is setup in Slack which points to microservice hosted on This service uses to process the user message and retrieve the meaningful actions from the message. Once the message is processed and retrieve the user actions, the service call the Particle Cloud APIs to control the lights or retrieve the sensor values.

On the Particle device side, a webhook is setup which points to an incoming slack webhook URL. The event corresponding this webhook is pslack. There are three particle functions defined in the firmware to retrieve the sensor values and to control lights. When these functions are called the firmware publish the event pslack with data. These events will trigger the Slack Incoming Webhook. The definition of the Webhook given below:

	"eventName": "pslack",
	"url": "<<Replace it with your Slack Incoming Webhook URL>>",
	"requestType": "POST",
	"rejectUnauthorized": false,
	"json": {
		"text": "{{SPARK_EVENT_VALUE}}"

User can interact with this Home Automation hub by sending Slack messages to a particular channel (in this case it is “particle”). Also the message should start with particle trigger word. For example sending the message “particle, what is the temperature in living room” will retrieve latest temperature, similarly “particle, what is the humidity in living room” will retrieve the humidity. User can also turn on/off particular lights by sending message like “particle, turn on living room light”, “particle, turn off living room light”, etc…

The microservice hosted in is written in Node.js. This service receives the text sends from Slack and send to for NLP processing. The will parse this test and return the user intention, location, actions etc… The service uses Node.js SDK to connect to the server and retrieve the results. After receiving the results from, the service calls corresponding Particle Functions to control the lights or retrieve the sensor values.

A pictorial representation of the interaction between the components is:

Setting up the project

  1. Create an account in, create a JavaScript hook and name it “callapiai” or whatever you want.
  2. Copy this code from Github and paste it to the hook just created and save it.
  3. Setup a Slack Domain and log on to it.
  4. Create a channel named “particle
  5. Go to Slack API and create an Outgoing Webhook and enter the following details
    Channel: #particle
    Trigger Word: particle
    URL: <<URL to the microservice created in Step 1>>
  6. Create an Incoming Webhook and enter the following details and note the Webhook URL
    Post to Channel: particle
  7. Open this slack.json file and replace the the URL of the incoming webhook and create a Particle Webhook using the particle cli command
    particle webhook create slack.json
  8. Create an account in and create a new Agent
  9. Go on to Settings->Export and Import and import the intents and actions from this ZIP file.
  10. Setup the hardware as per the Schematics below

Now the setup is ready and you can flash the Particle Photon and start using it.

Using the application

Log on to Slack and select the particle channel. Now you can type following commands and you can see the results. The should conversation starts with the slack trigger word particle or whatever you have given.

particle, turn on the bedroom light
particle, turn on the living room light
particle, turn on the kitchen light

particle, turn off the bedroom light
particle, turn off the living room light
particle, turn off the kitchen light

particle, what is the temperature in living room
particle, what is the temperature in bedroom
particle, what is the temperature in kitchen

particle, what is the humidity in living room
particle, what is the humidity in bedroom
particle, what is the humidity in kitchen

If everything goes well, you can turn on the lights and receive the temperature and humidity values.



Slack Outgoing Webhook

Slack Incoming Webhook Intent


Demo Video


I have a door bell connected to photon and I use zapier and webhook to get a message on “doorbell” channel each time when someone press our doorbell on CA flowdock ( similar service like slack) . It works fine. Zapier only give 100 messages per month. How do you do this my own ? I have to get the message to CA flowdock not slack. @krvarma @bko

@mallawa, I didn’t use Flockdock but I think you can get it done using their Flowdock REST APIs. As per the API documentation you can send message using Messages API. You can configure Particle Webhook to call Flowdock APIs.

Hope this helps!

Thanks. I was able to figure out, how to get this working… now there is a time out message generate when I hit the test button. constant “Bummer…” timeout messages. Wrt to webhook integration on particle side. Are their any bugs related to particle cloud ? It has been working nicely and stopped working 10 days ago. I tested with my terminal program and end url working fine… @Moors7 @bko @ScruffR @jonlogan @KyleG @will @peekay123 @JethroNull

Hi @mallawa

I don’t know anything about Flockdock but I would just make sure that you are paid up or truly are on the free plan.

A good way to debug problems like this is to create a bin at and temporarily change your web hook to hit that URL. Then you can see exactly what the web hook is doing and how it might different from what you are doing using cURL or web browser.


Zapier shows me I still have free zaps available out of 150. The test button also work on zapier portal and I can receive messages on Flowdock. If this doesn’t work on webhook intergration, I have to work on Google cloud intergration. Any documentation available how to set it up on gooflexible cloud. I already crrated an account and set it up on on particle side. But no clue how to do it on google side. Thanks @bko

@bko. Here is the scree shot of after changing the url. I didn’t get any respond here.

@bko Any thoughts ? If i want to get done same thing done using google cloud platform. Is there any documentation or samples tutorial I can find in this forum. I am still in the process understanding How google cloud platform works. Don’t know how to get started on google cloud platform side. @krvarma

Hi @mallawa

If you think you are publishing the event that triggers your web hook but it does not hit the then I think something is wrong with either your publish or your web hook definition. Are you sure you are running the code on the Photon that you should be and it is in a breathing cyan state?

I am sorry but I don’t know anything about Google Cloud Platform. Reading their marketing blurbs, they seem to specialize in large corporate clients.