Modbus Kiln System

This repository contains the PlatformIO projects for a kiln control system split into two ESP32-based applications:

• controller/: firmware for the gas kiln controller hardware
• hmi/: firmware for the operator display and web interface

The two devices communicate over Modbus RTU via RS485. Together they provide kiln control, operator interaction, schedule management, and logging support.

Repository Layout

controller/

Controller firmware for the ESP32-S3-based gas kiln controller. It is responsible for sensor acquisition, pressure input handling, control logic, and simulation support.

Key capabilities include:

• thermocouple input through the MAX31856
• 4-20 mA pressure input handling through the ADS1115
• Modbus communication with the external HMI
• simulation mode with a built-in web server for verification and tuning workflows

hmi/

Human-machine interface firmware for an ESP32-based TFT display unit. It provides local interaction on the display and browser-based tools for managing firing schedules and connectivity.

Key capabilities include:

• TFT-based local interface
• Modbus communication with the controller over RS485
• web pages for schedule creation and management
• InfluxDB logging for visualization in Grafana

Development

Both applications are PlatformIO projects.

Build the controller:

pio run -d controller

Build the HMI:

pio run -d hmi

Monitor serial output for either project at 115200 baud after uploading.

TODO

• add hardware files

License

This project is licensed under the MIT License. See the LICENSE file for the full text.