🛠 Premier clignotement d'une LED cousue

Objectives

Get familiar with the LilyPad Arduino SimpleSnap: clip on the 3.7 V LiPo battery, wire a LilyPad LED with conductive thread, upload the first sketch, and make a sewn LED blink. Understand the role of setup/loop, digitalWrite, and the pinout of the pads.

Materials

• 1 LilyPad Arduino SimpleSnap board (ATmega328P @ 8 MHz, integrated 110 mAh LiPo, snap buttons instead of sewable pads)
• 1 LilyPad LED (with integrated series resistor) and conductive thread, or two snap buttons
• 1 Arduino "USB Serial" FTDI adapter + USB cable
• Arduino IDE, with the "LilyPad Arduino" board selected (ATmega328P option for boards sold from 2012 onwards)
• >

Complete code

// Clignotement LED embarquée — LilyPad SimpleSnap (ATmega328P @ 8 MHz)
const uint8_t LED = 13;    // LED verte embarquée (pastille 13)

void setup {
  pinMode(LED, OUTPUT);    // la pastille devient une sortie
}

void loop {
  digitalWrite(LED, HIGH); // LED allumée
  delay(500);              // 500 ms — le timing est identique à 8 MHz
  digitalWrite(LED, LOW);  // LED éteinte
  delay(500);
}

Expected verification

The onboard LED blinks at 1 Hz (500 ms on, 500 ms off), running autonomously once the 3.7 V battery is clipped on. A sewn LED between pad 13 and the "−" pad blinks identically. The upload succeeds with the "LilyPad Arduino" board selected and the FTDI adapter connected to the corresponding pads.

Common errors

• Wrong board selected during upload (ATmega168 instead of ATmega328P): the sketch is rejected or the timing is incorrect.
• Conductive thread connecting "+" and "−": short circuit; above 5.5 V or with reversed polarity, the board is destroyed (official warning).
• LED sewn in reverse: an LED only conducts in one direction, so the thread must be reversed.
• Connecting the battery or FTDI adapter while the board is powered: handle the battery and adapter cable only when disconnected, before clipping them on.