1. Data acquisition

Danger

This tutorial is out of date. Please check the tutorials overview for our latest tutorials.

You start this tutorial by streaming data into a topic. Starting with the data feed enables you to verify that the code and services you build and deploy are working properly.

You have two options for this stage:

Stream data from your Android phone with the Quix Companion app.
Stream prerecorded CSV data.

You only need to set up one of these data sources for the purposes of this tutorial, although you are welcome to step through both approaches.

Quix companion app

External source

To get started with these steps you first need to add a Topic and pipeline placeholder called an external source.

An external source is a representation of a data source that is external to Quix, for example an IoT device or a service that is pushing data to a Quix topic using one of our API's.

To add an external source:

Go to the pipeline view.
Click + New in the top right corner of the view.
Select External source.
In Output select the topic you are going to publish to, or add a new topic with + Add new. In this case select the phone-data topic.
In Name type any suitable name, such as "Quix companion web gateway".
Click Add external source.

Install and configure the apps

To stream data from your phone you’ll need to install the Quix Companion App on your Android phone and deploy the QR Settings Share app to your Quix environment.

Follow these steps:

Install the Quix Companion App from the Google Play Store.
Open the app and navigate to the Settings page via the menu.
Click the SCAN QR CODE button at the top of the settings page. Now continue to follow these steps. When directed, in step #17, you will scan the QR code using the Quix Companion app.
In the Quix UI, click the user icon in the top right of the browser.
Click Tokens.
Generate a token with any name and allow at least a few days before it expires.
Copy the token to your clipboard or somewhere safe.
Navigate to the Code Samples and search for QR Settings Share.
Click Deploy.
Paste the token into the token field.
Click Deploy.
Open the QR Settings Share by clicking the "open in new window" icon.
Enter a name and a device identifier into the input fields.
These can be any value such as your name and CAR-001.
Click Generate Token.
A QR code will be generated and presented to you in the UI.
Scan the QR code using the Quix Companion App.

The app has now been configured with the access token, allowing it to communicate with Quix.
Ensure the rest of the fields are configured as follows:

a. Topic field is set to phone-data.

b. Notifications Topic field is set to phone-out.

c. DeviceId field is set to your chosen device identifier.

d. Rider is set to your name.

e. Team has a value. For example Quix.
Select Dashboard from the menu.
Click the START button.

This will open a connection to your Quix environment and start streaming data from your phone.

Verify the live data

Follow these steps to ensure that everything is working as expected:

In the UI, navigate to Data Explorer.
Ensure you are on the Live data tab.
Under Select a topic select phone-data.
Under select streams select the active stream. This should be the only stream that exists.
Under select parameters or events select gForceX, gForceY and gForceZ.
The waveform view should display the live g-force data from your phone.
Move or gently shake your phone and notice that the waveform reflects whatever movement your phone is experiencing.

Success

You have connected the Quix Companion App to your environment and verified the connection using the Live Data Explorer.

CSV data

If you don’t have an Android device, or you’d rather stream some data provided for you, then use this data source.

Follow these instructions to deploy the data source:

Navigate to Code Samples, select Python under languages and Source under pipeline stage.
In the search box enter Starter source.
On Starter source, click Preview code then Edit code.
Change the Name field to CSV data source.
Change the output field to phone-data.
Click Save as Application.
Open the requirements.txt file and add urllib3 to a new line.

Open the main.py file and replace the code with the following code:

import quixstreams as qx
import time
import os
import pandas as pd
from urllib import request

# Quix injects credentials automatically to the client. 
# Alternatively, you can always pass an SDK token manually as an argument.
client = qx.QuixStreamingClient()

# Open the output topic where to write data out
topic_producer = client.get_topic_producer(topic_id_or_name = os.environ["output"])

# Set stream ID or leave parameters empty to get stream ID generated.
stream = topic_producer.create_stream()

# download data.csv
# if you want to use your own data file just comment these lines
# and place your data.csv file in the same folder as main.py
f = request.urlopen("https://quixtutorials.blob.core.windows.net/tutorials/event-detection/data.csv")
with open("data.csv", "wb") as data_file:
    data_file.write(f.read())

df = pd.read_csv("data.csv")

for col_i in ['device_id','rider','streamId','team','version']:
    df = df.rename(columns={col_i: "TAG__" + col_i})

print("Writing data")
seconds_to_wait = 0.5

while True:
    for i in range(len(df)):
        start_loop = time.time()
        df_i = df.iloc[[i]]
        stream.timeseries.publish(df_i)
        print("Sending " + str(i) + "/" + str(len(df)))
        end_loop = time.time()
        time.sleep(max(0.0, seconds_to_wait - (end_loop - start_loop)))

qx.App.run()

Info

The code:

Connects to Quix.
Opens the CSV file using Pandas.
Renames some columns so Quix Streams streams them as tags.
Then streams each row to the phone-data topic.
It does this continuously so stop the service when you have completed the tutorial.

Test the code by clicking run near the top right corner of the code window.

With the code running you see messages in the Console tab:

[xx-xx-xx xx:xx:xx.xxx (8) INF] Topic phone-data is still creating
Opening output topic
Writing data
Sending 0/18188
Sending 1/18188
Sending 2/18188

Click the Messages tab and you see the raw messages being streamed to the phone-data topic.

Click one of the messages and you see the raw data in JSON format.

Your data should look like JSON

Note, depending on which row you click, you may see slightly different results. Only some rows contain location data.

"Epoch": 0,
"Timestamps": [
    1673966764000000000
],
"NumericValues": {
    "Longitude": [
    0.52202169
    ],
    "Latitude": [
    51.73491702
    ],
    "Speed": [
    98.0639991760254
    ],
    "Heading": [
    347.5
    ],
    "BatteryLevel": [
    0.27
    ],
    "Altitude": [
    59.63983154296875
    ],
    "Accuracy": [
    3.790092468261719
    ]
},
"StringValues": {
    "EnergySaverStatus": [
    "Off"
    ],
    "BatteryState": [
    "Discharging"
    ],
    "BatteryPowerSource": [
    "Battery"
    ]
},
"TagValues": {}
}

Stop the code by clicking the same button you clicked to run it.
You now deploy the code as a service, so it stays running when you navigate around in the UI.
Click Deploy.
On the dialog, click Deploy.

Once deployed, the service starts and data is streamed to the phone-data topic.

Detect crash events by following step 2