Project Hub /Basic Analog & Power Electronics/Analog Amplifiers & Signal Conditioning/OLED Soldering Controller

Intermediate

ARDUINO

₹500 – ₹1,500

3 – 6 Hours

Partial Kit

OLED Soldering Controller

Build a feature-rich, temperature-controlled digital soldering station using an ATmega328P microcontroller and an OLED display.

Originally published on CircuitDigest

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

0.96 Inch I2C/IIC 4pin OLED Display Module White Rs. 349.00
2-Slot 18650 Holder with Protective Cover and On/Off Switch – Case Rs. 109.00
Piezo Buzzer (Big) 6-12V Rs. 45.00
10pcs - 220 ohm 1/4 W Resistor Set Rs. 39.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

This list includes a generic resistor set as a placeholder — it is not matched to the exact value or part number this circuit needs. The correct one is specified on the original source page linked above; check it before buying.

We don't carry yet: ATmega / AVR chip
Transistors (BC547 / 2N2222 / TIP / MOSFET)
Crystal / Oscillator
Diodes (1N4007 / 1N4148 / Schottky / Zener)
Rotary Encoder
Capacitors
LMV358IDR

Browse all components

How It Works

The OLED Soldering Controller manages tip temperature through a closed-loop feedback system centered around the ATmega328P-AU microcontroller running on a 16MHz crystal/resonator. Because soldering iron thermocouple signals are typically very weak, the circuit uses an LMV358IDR operational amplifier to condition and boost the analog signal before the microcontroller's analog-to-digital converter reads it. The user adjusts the target temperature using an EC11 rotary encoder, while a 128x64 0.96” OLED screen driven by the U8glib library provides real-time visual feedback of the current and set temperatures. To heat the iron, the ATmega328P outputs a pulse-width modulation (PWM) signal that controls an S8050 transistor and an IRLR7843 MOSFET, which safely switches power to the heating element. Protection diodes including the SS34, 1N4148W, and Zener diodes (5V1 and 18V) safeguard the sensitive logic components from voltage spikes and reverse currents. A 78M05 regulator steps down the input voltage to provide a stable 5V rail for the digital logic, and an MLT-5030 SMD buzzer provides audible alerts for user interactions or status changes.

Why Build This

Design and implement a closed-loop Proportional-Integral-Derivative (PID) thermal control system suitable for precision engineering workstations.

Gain practical experience interfacing low-level analog operational amplifiers with microcontroller analog-to-digital converters for signal conditioning.

Construct a custom, bench-ready soldering station that prevents thermal damage to sensitive semiconductor components during prototyping.

Real-World Application

Precision electronics workbench tool for safe soldering of sensitive semiconductor components without overheating.

Skills You'll Learn

Operational amplifier signal conditioning

MOSFET power switching

PID temperature control loops

rotary encoder interfacing

OLED graphics programming

PWM power regulation

Safety Precautions

Exercise caution when working with high temperatures and line-powered heating elements to avoid burns or electrical shock.

Technology Tags

ATMEGA328P

OLED

PID CONTROL

SOLDERING STATION

ROTARY ENCODER

OP-AMP

THERMOCOUPLE

CHARGE PUMP

Frequently Asked Questions

Why is an operational amplifier like the LMV358IDR necessary?

Thermocouples in soldering irons generate very small voltage changes in response to temperature variations. The op-amp boosts this weak analog signal so the ATmega328P microcontroller can accurately read it.

What is the role of the IRLR7843 MOSFET?

The MOSFET acts as an electronic switch controlled by the microcontroller, allowing high current to be delivered to the low-voltage heating element via PWM without overloading the logic pins.

Can I use a standard display library instead of U8glib?

The software architecture relies on U8glib to drive the 128x64 0.96" OLED efficiently within the resource limits of the ATmega328P, so substituting it would require modifying the display handling code.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

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