Breadboard
A breadboard is a small board that helps you build circuits without soldering. It has many holes where you can plug in wires and electronic parts. Inside the board, metal strips connect some of these holes.
Breadboard internal connection diagram
The picture shows how the holes are connected inside the breadboard. Understanding these connections is essential for building working circuits.
Power Rails
The long vertical lines on both sides are called power rails. People usually connect the power supply to the rail marked with "+" and the ground to the rail marked with "-". Each hole in a rail is connected from top to bottom.
How Power Rails Work
You only need to connect your power source (for example, 3.3V or 5V) to one point on the "+" rail. After that, you can use any other hole on the same rail to power your components. The same applies to the ground rail.
Example: Powering Multiple LEDs
Connect the Pico's 3.3V pin to any hole on the + rail. Now you can connect multiple LED resistors to different holes on that same rail, and they all get power. Connect all LED cathodes (short legs) to holes on the - rail, and connect one wire from the - rail to Pico GND. All LEDs share the same ground.
Middle Area
The middle part of the breadboard is where you place most of your components. The holes here are connected in small horizontal rows. Each row has five holes that are linked together inside the board.
Horizontal Connection
Each row is separate, and the groups marked as a-b-c-d-e are separated from the groups marked as f-g-h-i-j by the center gap. The connections do not cross from one side to the other.
Connection Examples
Connected ✓
If you plug a wire into 5a and another wire into 5c, they ARE connected because they are in the same row on the same side.
Not Connected ✗
If you plug one wire into 5a and another into 5f, they are NOT connected because they are on different sides of the center gap.
Not Connected ✗
If you plug one wire into 5a and the other into 6a, they are NOT connected because they are in different rows (even though they're in the same column).
Why Use a Breadboard?
Benefits
- ▸No soldering required: Quick to build and modify circuits
- ▸Reusable: Components can be removed and reused in different projects
- ▸Learning friendly: Easy to fix mistakes and experiment
- ▸Organized: Keeps complex circuits neat with power rails
When building circuits, it's good practice to use consistent wire colors: red for power (3.3V or 5V), black for ground (GND), and other colors for signal wires. This makes troubleshooting much easier.