A smart enclosure for garbage cans based on an electrically height-adjustable desk. Controlled locally via push-button or via MQTT with an ESP32.

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Because the 3 garbage cans in our front garden had been an eyesore for many years and we now wanted a nice enclosure/covering for them. Last year the time had finally come. Of course, there are already countless off-the-shelf solutions available for this problem, but none of them are smart. So I thought: "Hey, why not completely over engineer a new solution for that problem?" 😉

I don't want to go into detail here about the construction of the wooden parts, because every situation on site is different and you have to build your own individual box anyway. Just this much: the desk frame is mounted on a raised wooden frame inside the box so that the maximum travel distance of 65 cm can be fully utilized. Meanwhile I have posted a video on YouTube about the enclosure, which also cover how it is constructed, e.g. the wooden structure. Unfortunately, it's in german, but maybe you will find it helpful anyway:

I use the EC5B frame from Flexispot, most (all?) Flexispot frames use Loctek Motion controllers so other models should also work, but of course I cannot guarantee this. The advantage of the Loctek Motion controllers is that the communication protocol has fortunately already been reverse engineered: A big thank you to https://github.com/iMicknl/LoctekMotion_IoT and others! The project would not have been possible without their preparatory work.

Beside the desk frame I used the following parts:

• ESP32 microcontroller
• old network cable
• Push button with RGB-LED ring, 19mm, 3-6V (https://de.aliexpress.com/item/1005003538108177.html)
• FR120N MOSFET (https://www.amazon.de/dp/B07HBQZ9BK)
• LED-Strip (I used a 24V variant, but 12V will also work)
• a suitable power supply for the LED-Strip

The following picture shows how all components are wired together:

• Push-Button for local operation
  • toggles between preset 1=closed and preset 2=opened (positions must be saved beforehand via the control panel)
  • when moving, pressing the button stops the movement
  • LED ring indicates the status of the action performed when the button is pressed
    • solid blue: button will open the box
    • solid red: button will close the box
    • flashing red: box is moving, button will stop movement
• LED-Strip support
  • The Led-Strip is activated from an opening height of 95 cm and deactivated again below this height
  • Dimming curve for activation/deactivation
• Control/Status over MQTT

Download the TrashStation.ino project and open it with your Arduino IDE. Adjust your WiFi and MQTT configuration in the file:

// WiFi- and MQTT Configuration const char* wifi_ssid = "******************************"; const char* wifi_password = "******************************"; const char* hostname = "TrashStation"; const char* mqtt_server = "192.168.x.x"; const int mqtt_port = 1883; const char* mqtt_user = "*********************"; const char* mqtt_password = "*********************"; const char* mqtt_topic_command = "trashstation/command"; const char* mqtt_topic_position = "trashstation/position"; const char* mqtt_topic_lwt = "trashstation/lwt"; // last will and testament const char* mqtt_topic_log = "trashstation/log";

If your GPIO assignment differs from the wiring diagram above, please also adjust it accordingly here:

//Loctek Motion controller pins #define displayPin20 4 // RJ45 connector of Loctek Motion controller: Pin20 for power on the desk controller #define rxPin 16 // RJ45 connector of Loctek Motion controller: RX-Pin #define txPin 17 // RJ45 connector of Loctek Motion controller: TX-Pin // Other pins #define togglePresetButtonPin 2 // single toggle button that switches between preset1/preset2 #define ledPinRed 21 // button led ring: red color #define ledPinGreen 22 // button led ring: green color #define ledPinBlue 23 // button led ring: color #define ledStripPin 19 // PWM-Signal for LED strip that illuminates the garbage bins (goes into a MOSFET that drives the LED strip)

Flashing the ESP32 with the TrashStation firmware is a straightforward process. Make sure your ESP32 is properly connected to your PC and that the necessary drivers are installed.

• Install the Arduino IDE
• Install the ESP32 board in the Arduino IDE via the Board Manager
• Add the following libraries in the Arduino IDE:
  • WiFi (included in the ESP32 core)
  • PubSubClient for MQTT support

Connect your ESP32 to your computer via USB. Check the assigned COM port in the Device Manager (Windows) or by running:

ls /dev/tty.*

(on Mac/Linux).

1. Open the TrashStation.ino file in the Arduino IDE.
2. In the Arduino IDE, select your ESP32 model under Tools → Board.
3. Select the correct COM port under Tools → Port.
4. Click Upload to flash the firmware onto the ESP32.

After a successful upload, open the Serial Monitor in the Arduino IDE (baud rate: 115200) to monitor the startup process. Look for messages such as:

WiFi connected MQTT connected

If you encounter issues:

• Verify the WiFi and MQTT settings in TrashStation.ino.
• Ensure your ESP32 is in the correct boot mode (press and hold the BOOT button while flashing if needed).

Once flashing is complete, your TrashStation is ready to use! 🎉