Ably Masterclass Episode 2 - Building an IoT based realtime attendance system for Slack

In this masterclass, Ably’s Developer Advocate, Srushtika Neelakantam, spoke about the basics of IoT and the realtime communication protocol these devices like to use i.e. MQTT.

She then demonstrated a realtime attendance system for Slack that could
• Detect the use of an entry keycard
• Publish this info in realtime to an Ably channel
• Ably, in turn, pinged Zapier
• Zapier, in turn, published this info on a Slack channel.

The links from the 7th slide are listed below:

Hardware components:
1. Adafruit Feather HUZZAH ESP866 - https://learn.adafruit.com/adafruit-feather-huzzah-esp8266/overview
2. MFRC522 RFID sensor - https://playground.arduino.cc/Learning/MFRC522/
3. Breadboard (Optional) - https://en.wikipedia.org/wiki/Breadboard
4. Jump wires - https://en.wikipedia.org/wiki/Breadboard#Jump_wires

Software components:
1. The Arduino IDE - https://www.arduino.cc/en/main/software
2. An account with Ably (free or paid) - https://www.ably.io/signup
3. An account with Zapier (free or paid) - https://zapier.com/
4. An account with Slack (free or paid) - https://slack.com/intl/en-gb/

Feel free to reach out to Srushtika via Twitter for any questions or concerns.

Transcript

1. Building an IoT based realtime
   attendance system for Slack
   Episode 2
   By Srushtika Neelakantam, Dev Advocate, Ably
   

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2. Ably - Serious realtime infrastructure
   Page 2 Srushtika Neelakantam | Ably Masterclass - Episode 2
   Hi there,
   I’m Srushtika
   Developer Advocate
   @Srushtika devrel@ably.io
   

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3. Ably - Serious realtime infrastructure
   Page 3 Srushtika Neelakantam | Ably Masterclass - Episode 2
   What will we build?
   +
   RFID- MFRC522 +
   Adafruit feather HUZZAH ESP8266
   1
   Ably MQTT broker
   publish msg
   (MQTT)
   2
   Zapier apps connector
   publish msg
   (WebHooks/ REST)
   3
   Slack messaging app
   publish msg
   (WebHooks/ REST)
   4
   

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4. Page 4 Ably - Serious realtime infrastructure
   Srushtika Neelakantam | Ably Masterclass - Episode 2
   AGENDA
   ● About Ably
   ● Working of MQTT
   ● Things you need
   ● Wiring the IoT components
   ● Understanding the code
   ● Working of WebHooks
   ● Setting up a Zap
   ● Ably Hub
   ● Live Q/A
   

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5. Page 5 Ably - Serious realtime infrastructure
   Srushtika Neelakantam | Ably Masterclass - Episode 2
   About Ably
   Realtime messaging
   APIs for event-driven
   applications.
   ● Minimal latency
   ● Reliability
   ● Message ordering
   ● Scalability
   ● Protocol interoperability
   

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6. Ably - Serious realtime infrastructure
   Page 6 Srushtika Neelakantam | Ably Masterclass - Episode 2
   MQTT
   IoT board
   MQTT broker
   (Ably)
   Devices
   Server
   Database
   publish msg
   subscribe
   publish msg
   subscribe
   publish msg
   subscribe
   publish msg
   

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7. Page 7 Ably - Serious realtime infrastructure
   Srushtika Neelakantam | Ably Masterclass - Episode 2
   Things you’ll need
   Hardware components:
   1. Adafruit Feather HUZZAH ESP866 - WiFi enabled board that works with the Arduino software
   2. MFRC522 RFID sensor
   3. Breadboard (Optional)
   4. Jump wires
   Software components:
   1. The Arduino IDE
   2. An account with Ably (free or paid)
   3. An account with Zapier (free or paid)
   4. An account with Slack (free or paid)
   

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8. Page 8 Ably - Serious realtime infrastructure
   Srushtika Neelakantam | Ably Masterclass - Episode 2
   Wiring the IoT components
   Huzzah pins RFID
   4 RST
   5 SDA
   13 MOSI
   12 MISO
   14 SCK
   3V 3.3V
   GND GND
   

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9. Let’s understand the code
   

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10. Page 10 Ably - Serious realtime infrastructure
    Srushtika Neelakantam | Ably Masterclass - Episode 2
    What’s happening in the code
    1. In setup method
    a. Set data rate
    b. Connect to WiFi
    c. Specify MQTT broker’s connection details
    d. Call the connect method
    2. In connect method
    a. Check if WiFi is connected
    b. If yes, connect to the MQTT broker
    3. In loop method (called repeatedly)
    a. Check if the RFID sensor has detected an access card
    b. If yes, get the ID of that card, match it with an employee name and publish that as a
    message to the Ably MQTT broker
    

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11. Ably - Serious realtime infrastructure
    Page 11 Srushtika Neelakantam | Ably Masterclass - Episode 2
    What will we build?
    +
    RFID- RC522 +
    Adafruit feather HUZZAH ESP8266
    1
    Ably MQTT broker
    publish msg
    (MQTT)
    2
    Zapier apps connector
    publish msg
    (WebHooks/ REST)
    3
    Slack messaging app
    publish msg
    (WebHooks/ REST)
    4
    

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12. Ably - Serious realtime infrastructure
    Page 12 Srushtika Neelakantam | Ably Masterclass - Episode 2
    WebHooks
    Ably Platform Server
    Hi, http://test/endpoint is my address. Call me if something happens
    publish msg
    (via REST)
    

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13. Page 13 Ably - Serious realtime infrastructure
    Srushtika Neelakantam | Ably Masterclass - Episode 2
    What else can you build with these components?
    - Send an SMS or a push notification when a high security file room is accessed by someone.
    - Monitor environmental data and constantly stream data to the Ably MQTT broker and make
    that data available via the Hub.
    - Home automation based on location tracking
    

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14. Page 14 Ably - Serious realtime infrastructure
    Srushtika Neelakantam | Ably Masterclass - Episode 2
    

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15. Q&A
    

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16. That’s all folks!
    Thankyou.
    @Srushtika devrel@ably.io
    Icons used in this presentation are from https://flaticon.com/
    

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