ESPHome-based LED strip controller: a smart device without programming

In the previous article, we described how to make an addressable LED strip controller and write firmware based on the 2Smart Cloud SDK. This article will show you how to write a fully compatible firmware for the same controller but based on ESPHome.

Why another article on creating a controller?

Details on how to make a LED strip controller and write firmware for it are here. The first article describes how to create firmware using the SDK of the platform for IoT product development, a powerful tool that we recommend to most vendors.

However, in many cases, ESPHome is a fairly functional tool. Its main advantage is simplicity. Using ESPHome, it will be easier for you to modify the firmware and add new functionality — for example, connect additional sensors and create a smart multitool.

You can use the firmware configuration provided in this article as part of the code configuration for a more complex device. You can also use the LED strip controller to compare two firmware creation tools for the ESP32 microcontroller: SDK and ESPHome.

What you need to get started

• Controller. You can find a list of components and a description of the assembly of the device in the previous article.
• Address LED strip.
• Power supply.
• USB-micro-USB cable for flashing.

Creating an ESPHome based controller firmware

1. Log in to the vendor account – https://cloud.2smart.com/.
2. On the “Products” page, click “Create Product” (the same button on the main screen launches a step-by-step assistant – the sequence of steps in the instructions below may vary slightly).
   
3. Select the microcontroller – ESP32.
   
4. Add the device name and icon – they will be displayed in the 2SmartCloud mobile app.
   
5. Click “Add Firmware” and select the ESPHome base.
   
6. Paste the controller firmware code into a new window. Documentation and ready-made examples for ESP Home will help you write the code. We used such sources:
   • platform for controlling RGB components – https://esphome.io/components/light/fastled.html;
   • a library of standard effects and instructions for writing your own – https://esphome.io/components/light/index.html#light-effects.

   After selecting the appropriate lines of code, we added controller effects and included support for the Reset button and Wi-Fi signal sensor in the firmware.

   Full code from our example:

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   light:
     - platform: fastled_clockless
       chipset: WS2812B
       pin: 18
       num_leds: 300
       rgb_order: GRB
       name: FastLED WS2812 Light
       id: light_rgb
       effects:
         - random: null
         - pulse:
             name: "Fast Pulse"
             transition_length: 0.5s
             update_interval: 0.5s
         - strobe: null
         - addressable_scan:
             move_interval: 50ms
             scan_width: 4
         - addressable_random_twinkle:
             twinkle_probability: 20%
             progress_interval: 100ms
         - addressable_color_wipe: null
         - addressable_rainbow: null
         - addressable_fireworks:
             name: Fireworks Effect With Custom Values
             update_interval: 32ms
             spark_probability: 10%
             use_random_color: false
             fade_out_rate: 120
   binary_sensor:
     - platform: gpio
       id: led_switch
       pin:
         number: GPIO5
         mode: INPUT_PULLUP
         inverted: true
       name: Led switch
       on_click:
         then:
           - light.toggle: light_rgb
     - platform: gpio
       id: change_effect
       pin:
         number: GPIO4
         mode: INPUT_PULLUP
         inverted: true
       name: Change effect
       on_click:
         then:
           - lambda: !<!lambda> |-
               uint32_t total = id(light_rgb)->get_effects().size();
               uint32_t curr_idx = 0;
               uint32_t i = 0;
               std::string curr_effect = id(light_rgb)->get_effect_name();
               auto call = id(light_rgb)->turn_on();
   
               // set first effect in list
               if (strcasecmp(curr_effect.c_str(), "none") == 0) {
                 call.set_effect(1);
                 call.perform();
   
                 return;
               }
   
               for (auto *effect : id(light_rgb)->get_effects()) {
                 i++;
                 if (strcasecmp(effect->get_name().c_str(), curr_effect.c_str()) == 0)
                   curr_idx = i;
               }
   
               if (curr_idx == total) {
                 call.set_effect(0);
               } else {
                 call.set_effect(curr_idx + 1);
               }
   
               call.perform();
     - platform: reset_sensor
       pin:
         number: GPIO0
         mode: INPUT_PULLUP
         inverted: true
       name: Reset button
       filters:
         - delayed_on: 1s
   sensor:
     - platform: wifi_signal
       name: WiFi1 Signal
       update_interval: 30s
       id: wifi_config
   
   

   
   
7. Save the firmware code. On the product screen, click “Build Firmware” for the test device. Enter the credentials of your Wi-Fi network – they will be transmitted to the device in the test firmware code for a quick Internet connection.
   
8. Wait until the firmware building is completed. Click “Download”.
   
9. Connect the controller to the computer using a USB cable.
   Attention! Disconnect the LED strip from the controller before proceeding with the flashing!
10. Unpack the downloaded archive, enter the folder with the received files and read the instructions for the flashing in the readme.md file.
    You can flash the device using Mac OS, Linux, and Windows devices; we used Mac OS.
    
11. Clear microcontroller memory – for Mac OS, this is the following command:
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     ./2smart.sh erase_flash -d /dev/tty.SLAB_USBtoUART.
    
    

    
    
12. Wait for the cleanup and run the firmware installation command:
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    ./2smart.sh write -d /dev/tty.SLAB_USBtoUART
    

    
    
13. After completing the firmware installation process, return to the platform – the device will connect to it automatically. The successful connection is indicated by a green indicator and the Ready status in the “Device Status” field.
    
14. Click “Preview State” and you will see the data of all device sensors.
    
15. Click “Add Layout” to open the mobile application emulator.
    

16. Appropriate widgets are automatically created for all sensors on your device. You can customize the appearance of the application as you like, including choosing other types of widgets than the default ones. You can also set a convenient order of widgets on the screen.
    
17. Please note – you can already control the device from the computer screen at this stage. After completing the interface configuration, click “Save”.
    
18. Launch the 2Smart Cloud mobile application on your smartphone; you have probably already used it to connect and control a virtual lamp. Log in with the same username and password that you used to register in the developer’s account.
19. Your new device is already displayed in the app. Please test the functionality of all widgets.
    
20. Return to the platform and click “Build Firmware” for the production device. The final version of the firmware will be built, which does not contain the parameters of your Wi-Fi network and other specific lines of code that are necessary for testing the prototype. Download the archive.
    
21. Click “Publish” – and the product will be available to users for pairing with a mobile device.
    
22. Flash the device with production firmware similar to the test firmware. Do not forget to clear the memory of the microcontroller beforehand.
    Attention! Disconnect the LED strip from the controller before proceeding with the flashing!Use the following commands:
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    ./2smart.sh erase_flash -d /dev/tty.SLAB_USBtoUART
    
    

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    ./2smart.sh write -d /dev/tty.SLAB_USBtoUART
    

    
    
23. Return to the mobile application, log in with any parameters as a regular user.
24. Click the “Add Device” button on the “Devices” screen – the pairing procedure will start.
    
25. Select “Others” from the list of devices available for pairing. Then click “Continue”.
    
26. Enter the credentials of your Wi-Fi network to transfer it to the device for connecting with the Internet.
    
27. After flashing the production firmware, the microcontroller opens a Wi-Fi hotspot with a name that matches the name of your device on the platform. Connect to this network in the next step.
    
28. Wait for the pairing to complete.
    
29. Now your LED strip controller is displayed on the Devices screen. Make sure you can control it from your smartphone screen.
    

That’s it! We have created a LED strip controller without programming and using assembler programs. The firmware code for ESPHome was written according to the documentation for this base. In fact, we just took ready-made examples and used them on our device.

Simplicity is the main advantage of ESPHome. Therefore, even if you plan to use firmware based on our SDK on production devices, we recommend testing the product using simpler tools. This reduces the time to create an IoT device.

The development of this idea is an LED lighting smart IoT solution where the controller described above controls the LED matrix, which is the basis for a smart lamp with multiple effects.