AKL-Mini SpezialEnglish

project overview
Year	2017
Number of pixels	18
Grayscales / Colors	greyscales
Illuminant	SMD LEDs
Power input
Contact person	Arne Rossius
Project website

AntiKippenLights-Mini Spezial (or AKL-Mini Spezial for short) is a regular AntiKippenLights-Mini extended with a second microcontroller to play a melody through a piezo speaker while the main controller is turned on. When the main controller is switched off, the melody keeps playing until its end is reached.

Hardware

In addition to the hardware of the AKL-Mini, the AKL-Mini Spezial uses an ATtiny11 controller to play the melody, an external resistor and capacitor to set the speed (as the ATtiny11's internal oscillator frequency is highly dependent on supply voltage) and a piezo speaker. An output pin on the main controller (ATtiny2313) is connected to an input on the ATtiny11 to send the "enable" signal.

The PCB is the same size as the AKL-Mini (45.7 x 30.5 mm, to fit a matchbox), but the LED heart has been extended and the LEDs rotated to match the heart shape. This provides plenty of space inside the heart to write a message (e.g. the names of a newlywed couple) or paste a heart-shaped photo.

Rev. 1.5

• Schematic (PNG image)
• Schematic (EAGLE 4.x)
• PCB layout (EAGLE 4.x)

Software

Main Controller (ATtiny2313)

See AKL-Mini Software

Melody Controller (ATtiny11)

The ATtiny11 does not support ISP programming and must be programmed with an AVR programmer capable of high-voltage (12V) serial programming. If it is already soldered to the PCB, it must be desoldered before it can be programmed.

The firmware supports two melodies, selectable with an input pin. The pin is read every time before the melody starts playing, so if its state is changed during playback, the controller will finish playing the melody before switching to the other one.

• Melody player (default melodies: Mendelssohn's Wedding March and Happy Birthday)

Construction Kit

• Construction kit instructions for PCB Rev. 1.5