ElectroLab AIPi

Raspberry Pi bench guide

Raspberry Pi 40-pin header layout and safe wiring guide.

Explore the physical header pins, BCM GPIO names, starter schematics, and the safety rules that keep Pi projects friendly to the board and the person wiring it.

Safety first, always.

ElectroLab AI teaches theory, low-voltage electronics, and planning concepts. Mains voltage, switchboards, fixed wiring, high-current systems, and legal electrical work must only be performed by licensed electricians where required.

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Physical pin view

Raspberry Pi 40-pin header layout

Click a pin to learn what it is for. The numbers shown here are physical header pin numbers, which are different from BCM GPIO numbers.

Official GPIO docs
Odd side

Schematic

GPIO LED indicator

Blink an LED from GPIO17 without overloading the pin.

Never connect an LED straight from GPIO to ground without a resistor.

Raspberry Pi40-pin header330RGPIO17 pin 11GND return

Pins used

  • Pin 11: GPIO17
  • Pin 9 or 14: GND

Bench steps

  1. 1GPIO17 goes to a 220 to 470 ohm resistor.
  2. 2The resistor goes to the LED anode, the long leg.
  3. 3The LED cathode, the short leg, returns to a GND pin.
  4. 4Start with the Pi powered down, wire it, then boot and test with a small blink script.

3.3 V GPIO only

Raspberry Pi GPIO pins are 3.3 V logic pins. Feeding 5 V into a GPIO can permanently damage the board.

GPIO is signal, not power

Use driver circuits for motors, relays, solenoids, LED strips, and other higher-current loads. Add flyback protection for coils.

Grounds matter

Low-voltage modules need a shared reference ground unless the interface is deliberately isolated.

Reality check

The official Raspberry Pi documentation describes the GPIO and 40-pin header across modern boards, but pin headers can be unpopulated on some variants and add-on boards may reserve pins. Check your exact board, HAT, and module before wiring.