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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

Empty solderless breadboard

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.

Breadboard top and underside connections

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

Power rails are often split in the middle

A full-size board has a + / − pair on each long edge. Every one of those four columns is usually two halves — the top half is not joined to the bottom until you bridge the gap. Look for a break in the red/blue line halfway along the edge.

Breadboard with + and − rails on both long edges; each rail split mid-board and bridged with a short jumper

Four bridges if you use both edges: left +, left −, right +, right −. If you only use one edge for 3V3/GND, still bridge both + and − on that edge.

3. Pick the rails for this project

Choose one + rail and one − rail (same edge is simplest). Later steps put 3V3 on + and GND on −, then the ESP32-C3, VEML7700, LED, and display take power from those rails.

If your rails split in the middle, put a short jumper across each gap on the edge you use (+ to +, and − to −) so that edge is one continuous net end to end. Bridge the other edge too if you will use it. Skip this only if you have confirmed the rail metal is continuous.

Leave space for the ESP32-C3 across the centre trench and for the modules beside it so the jumpers stay readable.

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