Physical details:
Physical details:
Hardware details:
Large scale production:
Instead of using the standard Arduino interface, a script is used to build the binary.
A second script allows code uploading in ~10 seconds / card - much faster than using arduino and avoiding clickin on upload button.
A specific connector have been designed to ensure quick and foolproof programmer positionning.
The card being 0.8 mm thick while the standard USB connector is 2.2 mm, a thickener need to be glued on the card. The cheapest way to produce this thickener is to order a PCB matrix (cost : 2 cents / thickener).
A 3D printed shape is used to position the thickener at the exact location and reduce the assembly time.
Software & SOC details:
The software is programmed in C language and compiled using the Arduino platform for Attiny1616 (using Megatinycore programmer). The main library used is Protodome's MMML player (modified to add special effects such as glissandi or volume decay).
A cloud tool was developped to let the music expert compose the tune without needing to install any tool. This tool can both generate wav files for the musician or MMML/Avr bytecodes (that will be inserted into the arduino code). here.
The attiny1616 chip has a large number of I/Os (needed to command the leds) and a 16 kb flash ram. Documentation is available here.
Costing details:
The most expensive components used are attiny1616 system on chip (~0.4 $), MLT-9032 electromecanical buzzer (0.2 $). Total cost including PCB and assembly before taxes and shipping is ~1.5 €/unit for large batchs : postage (1.16 € for France)is by far the most expensive part of the project.
Here are some of the tunes used (click to play):
Credits:
Project, assembly, shipping: Arthur & Vincent C.
Software, parts selections, tests : Arthur & Vincent C.
Hardware design : Shaikh Abdul Mobeen.
Music : Matias Sosa.
MMML format : Blake Troise 'Protodome'.