YARC - Yet Another Reflow Controller

ESP32 reflow oven controller with LVGL UI, PID thermal control, and web monitoring

Project Overview

YARC is an ESP32-based reflow oven controller for converting a toaster oven into a controlled solder reflow system. It combines a live LVGL TFT interface, K-type thermocouple feedback through a MAX6675, solid-state relay heating control, and phase-specific PID tuning for the reflow process.

Education Context

I built this project during my State-Certified Electronics Technician program in Digitalization & Information Technology at Berufsbildende Schule Suedliche Weinstrasse.

Embedded Stack

ESP32Arduino / PlatformIOLVGL 7TFT_eSPIMAX6675DS3231 RTCSPIFFSESPAsyncWebServerWebSocketPID Control

Web Interface

The ESP32 hosts the SPIFFS-served browser UI directly from the device. A WebSocket stream powers the live monitoring chart; profiles are persisted in JSON on the controller.

Landing page served from the ESP32 — entry points to live monitoring and profile management.

Key Features

Five-phase reflow state machine: IDLE, PREHEAT, SOAK, REFLOWRAMP, REFLOW, and COOLDOWN.

Separate PID tuning values for preheat, soak, and reflow phases.

On-device LVGL TFT display for status, temperature, profile data, and process feedback.

ESP32 WiFi access point with a browser interface served from SPIFFS.

WebSocket monitoring stream for target and measured temperature, including CSV export.

Reflow profile creation, listing, removal, and persistence through SPIFFS-hosted JSON data.

Source

The firmware, web assets, configuration examples, profile storage, and build setup are available in the public GitHub repository.

Open GitHub Repository