Breadboard
wiring without soldering
A plastic board with holes into which you push components and wires. Inside, metal strips connect the holes by a fixed rule — so you build a circuit without soldering and can change it as often as you like.
Open the course →How it works
Middle area: the holes are arranged in rows labelled with letters (a–e and f–j) and columns with numbers (1–30 or 1–63). Within one column, holes a-b-c-d-e are connected to each other, and separately f-g-h-i-j. The groove in the middle separates the two halves — that is where integrated circuits go. Power rails (along the sides, with + and − lines): all holes along one line are connected. You bring 3.3 V / 5 V and GND there, so every component gets power easily.
Pins and wiring
| Pin | What it is | Where it connects / why |
|---|---|---|
| Column a–e | Five connected holes | Everything you put in the same column (e.g. 20a, 20b, 20c, 20d, 20e) is electrically joined. |
| Column f–j | Five connected holes, separate from a–e | The groove separates them. 20e and 20f are NOT connected. |
| + rail (red line) | Horizontal power rail | Connect 3V3 or VIN from the ESP32. On some boards the rail is split in the middle — check with a multimeter. |
| − rail (blue/black line) | Horizontal ground rail | Connect GND from the ESP32. Every component that needs GND returns here. |
Specifications
Size (half)400 holes, 30 columns
Size (full)830 holes, 63 columns
Pitch2.54 mm (0.1″)
Max current~1 A per contact
Wire gauge22 AWG (0.65 mm) ideal
Tips and typical mistakes
- The ESP32 DevKit V1 (30 pins) goes at the end of the breadboard: the pins go into rows b and i, leaving one free hole (row a and row j) next to each pin for a wire. The USB connector hangs over the edge — that is normal.
- Use red wires for +, black for GND — mistakes are much easier to find.
- If something does not work, first check whether components accidentally share a column (short circuit).