LED module (with resistor)

The LED module is the classic first circuit — a red LED soldered in series with its 330 Ω resistor — pre-wired so there is nothing to get wrong. It costs $2 and is for anyone who wants a status light working before they have learned Ohm's law: SIG goes to a GPIO, GND to ground, and the LED lights whenever the pin is high.

What's inside

Part	Qty	Price each
LED	1	$1
Resistor	1	$0.25
Total	2	$1.25

The red LED does the glowing; its forward voltage is about 2 V, so 3.3 V drives it comfortably.
The 330 Ω resistor sits in series between SIG and the LED's anode and holds the current at roughly 4 mA — clearly visible, far below the LED's 20 mA rating.

Exposed pin	Inside the kit
sig	`r:1`
gnd	`led:K`

sig is the free lead of the resistor and gnd the LED's cathode, so current flows GPIO → resistor → LED → ground. The module has chain ends, so pi.GPIO17 >> module >> pi.GND is a valid shorthand for the two connections below.

Wiring it in circuit.py

circuit.py

from wiring import *

pi = Pi()
module = kits.LEDModule()

pi.GPIO17 >> module.sig     # through the 330 Ω resistor
module.gnd >> pi.GND

Driving it in main.py

main.py

from gpiozero import LED
from time import sleep

led = LED(17)

while True:
    led.on()
    sleep(0.5)
    led.off()
    sleep(0.5)

Why buy the kit

Hand-wired, the parts are $1 for the LED plus $0.25 for the resistor — $1.25 — against $2 for the module. That 75¢ buys the soldering, the correct resistor value and no polarity mistakes: a guaranteed light instead of a circuit to debug. If you want a different brightness or colour, buy the loose parts instead; the kit fixes the resistor at 330 Ω and the LED at red.

Simulator vs real hardware

The kit is billed as one shop item, and its two parts are drawn as a labelled group — but they are still simulated as an LED and a resistor, so current, PWM brightness and burn-out behave exactly as on the LED and resistor pages.
Only the kit's own pins (sig, gnd) are reachable from circuit.py; the internal wire is fixed.
The 330 Ω value is baked into the kit, so an overcurrent mistake is much harder to make: a 3.3 V GPIO through 330 Ω stays near 4 mA even if you leave the pin on.