3D Printer Filament Dryer Controller

A project based on ESP32 & TFT TouchScreen to control heater for a DIY 3D Printer filament dryer.

For the UI LVGL 9 and EEZ-Studio are used, with some automation done with EEZ-Flow.

The controller is connected to MQTT Broker via WiFi, to send sensors and actuators data and also to permit remote control.

Node-RED is used to interact with MQTT data and command and to show a dashboard.

MQTT Topics

The {base_topic} is defined in the code:

#define MQTT_BASE_TOPIC "itlab/dryer"

There are some topic used to send sensors values and other realtime data from board to the Broker:

• {base_topic}/reg_mode -> current regulation mode (0..3)
• {base_topic}/sensors -> json with sensors values: {temp: 23, humi: 60}
• {base_topic}/rtdata -> json with realtime data values: {"mode":0,"target":0,"heater_pwm":0,"fan_pwm":0,"led_pwm":0,"remaining_time":0}

There are some topic the board use to receive remote commands from the Broker:

• {base_topic}/commands/remote_mode_override (int) -> override the regulation mode (0:off, 1:temp, 2:humi, 3:remote)
• {base_topic}/commands/heater_pwm (int) -> pwm out value (0/255) for heater
• {base_topic}/commands/fan_pwm (int) -> pwm out value (0/255) for fan
• {base_topic}/commands/led_pwm (int) -> pwm out value (0/255) for led

Libraries dependencies

The project uses the following libraries from PlatformIO registry :

• XPT2046_Touchscreen by Paul Stoffregen to use the Touchscreen - https://github.com/PaulStoffregen/XPT2046_Touchscreen
• TFT_eSPI by Bodmer to use the TFT display - https://github.com/Bodmer/TFT_eSPI
• lvgl v9 by LVGL - https://github.com/lvgl/lvgl
• BME280_Light by Tomasz 'Zen' Napierala
• PicoMQTT - https://github.com/mlesniew/PicoMQTT
• PID_V1 - https://github.com/br3ttb/Arduino-PID-Library/

See the file platformio.ini for the lib_deps options listing used libs.

Screenshots

LVGL GUI

Node-RED Flow & Dashboard