Breadboard¶

Nothing is wired yet. The plastic board already has metal clips under the holes — those clips decide what is connected. Learn that map before you seat any jumpers.

Before you start

Parts from the overview on the desk. Breadboard empty. No jumpers seated yet.

1. Look at your board¶

A typical full-size board. Yours may be half-size (400 holes) or full-size (830). The rules below are the same.

Find these three things on yours:

What	Where
Centre trench	The groove down the middle
Letter columns	`a–e` on one side of the trench, `f–j` on the other
Power rails	The long `+` (often red) and `−` (often blue) columns along the edge

2. What's already connected¶

Pull the sticky backing off a spare board once in your life and the clips look like this. You don't need to strip yours — the photo is enough.

Left: top. Right: metal clips underneath. Short clips = rows of five. Long clips = power rails.

Region	How the holes are tied
Terminal strips	Each numbered row of five (`a–e` or `f–j`) is one net. Same number across the trench is not joined
Power rails	Each `+` column is one long net. Each `−` column is another
Rail gaps	Many boards break each rail halfway. A short jumper across the gap joins the two halves

3. Pick the rails for this project¶

Choose one + rail and one − rail. Later steps put 3V3 on + and GND on −, then every module takes power from those rails.

If your rails split in the middle, put a short jumper across each gap now so the whole rail is one continuous net.

Check¶

You can point to your chosen + and − rails
You know a pin in a1 does not connect to f1 (trench in between)
Mid-rail gaps are bridged, or you confirmed your board has continuous rails

If it fails¶

Symptom	Fix
Two parts share a row number but don't talk	They're on opposite sides of the trench. Jump across, or move both to the same side
Only half the rail has power later	Mid-rail gap. Bridge it with a short jumper

Credit: empty board oomlout (CC BY-SA 2.0); connections photo Guhuru (CC0).

Checkpoint 1¶

I can point to the + rail and the − rail I'll use for 3V3 and GND
I know the left and right halves of a row are not connected
Mid-rail gaps are bridged, or my rails are continuous

Stop here until every box is ticked.

Next: ESP32