alexcorvis84 / slackbot

ESP32 Slack Bot 🤖 for IoT projects

ESP32 Slack Bot 🤖 for IoT projects

Project Background

When I joined empathy.co in order to lead the Labs Team, one of the first questions I asked myself was:

How could I explain to new colleagues what’s the mission regarding empathy LABs (eLABS)? 🤔

People who know me closely know that I’m a new technology enthusiast. I like to prototype ideas 💡 that could become a solution to a problem. I love the ‘Do It Yourself’ philosophy and Maker culture as I consider it’s a great example of this design process:

Research → Draft → Prototype → Review → Refine

That’s why I considered that the best way to let you understand the mission of eLABS was by doing something practical, something that could serve as a great example and... What better way than prototyping something useful?

That’s the reason I came up with the following idea:

At empathy.co we use a Slack workspace as a communication channel as many companies out there nowadays. I had never used Slack previously, but since I joined the company and started using it the following weeks I came up with the idea that some tasks could be automated with a Slack Bot integration.

So this marks the start point of any kind of prototype:

1. The idea 💡

The idea of this integration is to use a microcontroller ESP32 directly connected to the Internet via Wi-Fi in order to create a Bot designed to interact with users via chat messages.

A bot 🤖 is the same as a regular app: it can access the same range of APIs and do all of the ‘magic things’ 🧙 that a Slack App can do, but when you build a bot for your Slack App, you're giving that app a face, a name, a personality and encouraging users to talk to it.

Bots can automate some actions or even enhance user notifications with digital displays like a Neopixel LED strip 🌈

Integration examples:

• Enhance notifications with digital displays (user mention, channel, etc)
• Monitoring (room conditions, occupancy, etc)
• Remote control of any mechanism (remote control door opener, IoT, etc)
• ...
• Any idea you would like to automate! 💡🤔💭

2. The prototype ✍️

Once you get the idea, the prototyping phase starts.

I usually draw a basic draft of the architecture of the application in a notebook following some kind of my own ‘Design Thinking’ process.

Below you can find the very first draft idea I realized: how could we automate e.g., the parking door opening? 🤔

With the blink of an eye, you can easily understand how it will work or get the point. Am I right? 😉

3. The build 🛠️

When you build something related to any 3rd party vendor services, there’s no other way to learn them than researching and reading through their online documentation. Luckily, Slack has a great documentation published online about their available APIs.

The prototype uses an ESP32 controller implementing the Real Time Messaging API which is based on a WebSocket connection.

One of the most valuable things about the Maker community is their love and passion to share the projects as Open Source and under Open Source Licenses that makes it possible for you to reuse their work. Luckily I was able to find on the Internet that a user @urish had the same idea as me (4 years ago though!) and implemented a Slack Bot with the same API.

I looked into their source code available which helped me not to start from scratch the build process. But, what happened? I realized that some things did not work as I expected or were missing… 😟

So I developed my own source code based on his work (thanks again!) and started to code my own ‘fork’.

4. Code improvements ✨:

• Project is portable: you can bring with you the prototype wherever you want and you will just need to follow the Wi-Fi configuration portal to set up your Wi-Fi network to be used.

  • No need to hardcode your Wi-Fi credentials anymore as it uses a Wi-Fi manager library!

• Personal/channel/group notifications: you could set up the prototype to be used as a personal notification gadget at the side of your desk.

  • For instance, you could show some animations on a NeoPixel Ring / Strip or even play an alarm sound whenever e.g., your user name (<@MEMBER_ID>) is mentioned on any channel!

• Project based on ESP32: which means you have more GPIOs available to connect any sensors, actuators, displays, lights...

  • The ESP32 is much more powerful 💪!

• Parse any word from any message sent to the bot: you can look for any word sent on any message.

  • It opens great possibilities to develop your own solutions based on personalised commands 🤔💡💭!

• Project build with PlatformIO: no need to install manually libraries or depencies. Just download source code, open it with PlatformIO, connect your ESP32 board, select the right Serial port and upload.

  • PlatformIO will automatically download all the necessary resources 🎩✨! You will just need to setup your own configuration variables accordingly

Code configuration 🎛️

Slack SSL SHA-1 fingerprint

#define SLACK_SSL_FINGERPRINT "C1 0D 53 49 D2 3E E5 2B A2 61 D5 9E 6F 99 0D 3D FD 8B B2 B3"

If Slack changes the SSL you would need to update with the new SHA-1 fingerprint. You can check it by looking at certificate details when accessing the Slack API website.

Slack App and Bot integration

1. Get token by creating a classic Slack App at https://api.slack.com/apps?new_classic_app=1
2. Add a Bot User to your App
3. Then install your App to your Slack workspace to generate the Bot User OAuth Access Token
4. Set the following OAuth Scopes: channels:read / chat:write:bot / bot / incoming-webhook
5. Locate your <@MEMBER_ID> in your Slack Space: you can find it in Profile & account -> ... (3 vertical dots) -> Copy Member ID
6. Then setup your own values in source code '/src/main.cpp'

#define SLACK_BOT_TOKEN "Your_Bot_User_OAuth_Access_Token"
#define MEMBERID "<@MEMBER_ID>"

Wi-Fi Configuration

The code uses the WifiManager library, which eases the W-Fi configuration.

Once the code has been uploaded, the ESP32 will create by default a Wi-Fi Access Point called “EmpahtyBot_AP” and password “labs2020”.

You can change the settings by your own modifying below code line in '/src/main.cpp'

!wm.autoConnect("EmpathyBot_AP","labs2020")

Connect to it using any WiFi enabled device with a browser (computer, phone, tablet) and then the Web Captive Portal will start.

You will be able to scan and set up your Wi-Fi connection.

Select your Wi-Fi SSID, enter your password, click save & you’re ready to go!

If you need to reset settings to default, just uncomment the below line ('/src/main.cpp') & upload code to the board again.

    wm.resetSettings();

DEMO SETUP CONFIGURATION 🛠️ 🧰

Hardware Setup

• ESP32 DevkitC obviously! 😆
• 16 LED NeoPixel ring 🌈 connected to GPIO32
• BME280 sensor 🌡️ (I2C: connected as → SDA GPIO21 - SCL GPIO22 - GND - 3.3V)
• LED 💡 connected to GPIO27
• Servo 🏗️ connected to GPIO26
• RCWL-0516 👋 Microwave proximity sensor connected to GPIO35
• 12V Relay 🔌 connected to GPIO12 (relay is connected to a 12V Sound Alarm as example)

Default Commands

• red / blue / green → The NeoPixel ring will show the color selected

• off → The NeoPixel ring will go off

• 🚪 → If the door emoji is sent, the servo will be activated (ie: in demo setup configuration the servo press down the button of a remote controller which opens a Garage door)

• room_status → The bot will reply back to the user with the information from the BME280 sensor (temperature & pressure) & the microwave sensor will detect if there is someone in the room where the device is placed, being useful to know if it is free or not.

If the message sent by any user contains your <@MEMBER_ID> in the Slack #channel where the Bot has been integrated, the NeoPixel ring will show you an animation & then the sound alarm connected to the 12V relay will be turned on for a few seconds.

Check VIDEO example running.

What will you build next?

Now it is your turn to come up with awesome ideas 💡 for Slack device-bots and build them.

Here are some ideas:

• Personal notification desk lamp. Design & 3D print your own Slack notification desk lamp 🖥️🛎️
• Surveillance system. Receive photos if motion is detected! 📸
• Remote control. Automate any IoT project! 📡📲

LICENSE 📋

MIT License - Copyright (c) 2020 Alejandro Juan Garcia