Arduino Lilypad

The LilyPad Arduino is designed for e-textiles and wearables projects. It can be sewn to fabric and similarly mounted power supplies, sensors, and actuators with conductive thread. The LilyPad Arduino Main Board is based on the ATmega168V (the low-power version of the ATmega168) or the ATmega328V.

Technical Specs

• • Microcontroller: ATmega168 or ATmega328V
  • Operating Voltage: 2.7-5.5 V
  • Input Voltage: 2.7-5.5 V
  • Digital I/O Pins: 14
  • PWM Channels: 6
  • Analog Input Channels: 6
  • DC Current per I/O Pin: 40 mA
  • Flash Memory: 16 KB (of which 2 KB used by bootloader)
  • SRAM: 1KB
  • EEPROM: 512 bytes
  • Clock Speed: 8 MHz

OSH and Schematics:

Schematics: https://www.arduino.cc/en/uploads/Main/LilyPad_schematic_v18.pdf

Eagle Files: https://www.arduino.cc/en/uploads/Main/LilyPad_Board_v18.zip

Detailed pin description:

Power

The LilyPad Arduino can be powered via the USB connection or with an external power supply.

If an external power supply is used, it should provide between 2.7 and 5.5 volts. This can come either from an AC-to-DC adapter (wall-wart) or battery. Again, don’t power the LilyPad Arduino with more than 5.5 volts, or plug the power in backwards: you’ll kill it.

Input and Output

Digital I/O:

Each of the 14 digital pins on the Lilypad can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. In addition, some pins have specialized functions:

• Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. These pins are connected to the corresponding pins of the FTDI USB-to-TTL Serial chip.
• External Interrupts: 2 and 3. These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details.
• PWM: 3, 5, 6, 9, 10, and 11. Provide 8-bit PWM output with the analogWrite() function.
• SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication, which, although provided by the underlying hardware, is not currently included in the Arduino language.
• LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it’s off.

Analog Inputs:

The Lilypad has 6 analog inputs (A0 to A5), each of which provides 10 bits of resolution (i.e. 1024 different values). By default, they measure from ground to 5 volts, though is it possible to change the upper end of their range using the analogReference() function. Additionally, some pins have specialized functionality:

• I2C: 18 (SDA) and 19 (SCL). Support I2C (TWI) communication using the Wire library (documentation on the Wiring website).

Communication

The Lilypad has three modes of communication. Serial communication, I2C (TWI) and SPI. The Serial communication which is available on digital pins 0 (RX) and 1 (TX).

Physical Characteristics

The LilyPad Arduino is a circle, approximately 50mm (2″) in diameter. The board itself is .8mm (1/32″) thick (approximately 3mm (1/8″) where electronics are attached).

Programming

The LilyPad Arduino can be programmed with the Arduino Arduino Software (IDE). Select “LilyPad Arduino” from the Tools > Board menu (according to the microcontroller on your board).

The ATmega168V or ATmega328V on the LilyPad Arduino comes preburned with bootloader that allows you to upload new code to it without the use of an external hardware programmer.

You can also bypass the bootloader and program the microcontroller through the ICSP (In-Circuit Serial Programming) header. While the holes are too small to insert pins into, you can insert male header pins into the ISP connector on your programmer and press them against the ICSP header on the board (from above).

Washability

Wash at your own risk – we do ;). We recommend washing projects by hand with a mild detergent. Drip dry. Make sure you remove your power supply first!