YKR038 COURSE · MODULE 1 · LESSON 04

Understand the Breadboard and Jumper Wires

Learn how breadboard rows and power rails connect before building live circuits.

20 minComplete beginnerGetting Started
BUILD WITHBreadboard
PROGRAMESP32
ACHIEVEYou can place components and route…
Written for complete beginners

Follow the numbered steps in order. Do not connect USB power until the wiring step tells you to. Compare every pin label before continuing.

LESSON GOAL

What you will build and learn

In this lesson, you will learn breadboard connectivity, polarity, and shared ground. By the end, you can place components and route power without accidental short circuits.

  • Recognize the purpose of each required part.
  • Make the connections in a safe, repeatable order.
  • Upload or run the lesson procedure and verify the expected result.
  • Use observable evidence to fix common problems.
Real YKR038 wiring photo reserved

A close, labeled photograph of this exact experiment will be added here. Until then, use the written pin-by-pin connection list below.

STEP-BY-STEP GUIDE

Build the experiment

1

Understand the target result

Learn how breadboard rows and power rails connect before building live circuits. The expected result is: You can place components and route power without accidental short circuits.

2

Prepare the board and parts

Disconnect the ESP32 from USB. Put the ESP32, breadboard, jumper wires, and the listed lesson parts in front of you. Straighten bent pins gently and never force a module into the breadboard.

3

Make each connection with power off

  1. Keep the USB cable disconnected while placing parts.
  2. Use the breadboard row markings to trace connected holes.
  3. Create one 3.3V rail and one GND rail; never join them together.

Power check: confirm that no 5V signal goes directly into an ESP32 GPIO and that 3.3V is not connected to GND.

4

Complete the software or inspection task

No additional Arduino library is required for this starter sketch. Select your ESP32 board and serial port before clicking Upload.

  • Open Arduino IDE and confirm the correct ESP32 board is selected.
  • Follow the on-screen or inspection actions described in the wiring list.
  • Do not continue until every required item is visible and correctly configured.
5

Power the circuit and observe

Connect USB power only after the wiring check. Open Serial Monitor at 115200 baud when the sketch prints data. Watch the circuit for at least 20 seconds and compare it with this expected behavior: You can place components and route power without accidental short circuits.

6

Change one value and test again

Make one small change—such as a delay, threshold, brightness, or displayed message—then upload again. This confirms that you understand which part of the program controls the result.

WHY IT WORKS

The key idea

This experiment demonstrates breadboard connectivity, polarity, and shared ground. The ESP32 repeatedly reads or updates the connected hardware, applies the program logic, and produces the observable result. Changing one input or one code value helps you see that relationship directly.

Input or instructionESP32 logicMeasured result or output

TROUBLESHOOTING

If the experiment does not work

Nothing powers on

Disconnect USB. Check the USB cable, 3.3V/5V selection, GND rail, and breadboard row placement.

Upload fails

Confirm the board and port. Close other serial programs, reconnect USB, and hold BOOT only if your board requires it.

Result is unstable

Shorten jumper wires, confirm a shared ground, and verify that input pins are not floating.

Lesson-specific check

Disconnect USB power before moving wires.

VIDEO WALKTHROUGH

Hands-on lesson video reserved

The final video will show the real YKR038 parts, every wire connection, the upload process, and the expected result.