What they are and how they work
The kit includes 30 jumper wires: 10 F–M, 10 F–F and 10 M–M. M means a male end with an exposed metal pin; F means a female socket. A wire creates an electrical connection between two points without soldering. It does not convert voltage or protect against incorrect wiring.
M–M wires have pins at both ends for breadboard holes or female headers. F–F wires connect two male headers. F–M links a module's male pin to a breadboard or female connector. The correct choice depends on both physical endpoints, not their purpose in software.
What we can use them for
- Connect ESP32 and sensor headers with suitable F–F wires.
- Bring a module signal to a breadboard using F–M.
- Link separate breadboard rows or power rails using M–M.
First exercise
Sort wires by connector type. With power disconnected, join two separate breadboard points and check continuity using a multimeter. Sketch three connections for a simple sensor and select appropriate ends before wiring. Use consistent colours for ground, power and signals, and record the colour convention on the sketch.
Handling notes
Insulation colour alone does not determine a wire's function. Pull the plastic housing rather than the wire and replace loose connectors. Exposed pins must not touch neighbouring connections. These wires suit small low-voltage prototypes, not mains voltage or high current.
Source: SparkFun — Connector Basics.