We’ve recently built a highly miniaturized Arduino (pictured below) that may be interesting to some of the members of this forum. It’s in the form of a 10mm x 10mm x 1.5 mm encapsulated module attached to a 25 conductor polyimide flex cable with conductor pitch of 0.3mm.
The module includes an Atmega 328P chip with a 2.8v LDO regulator, an inverter that is useful for interrupt management, a dedicated I2C interface, an SPI interface and several other digital and analog I/O options. Schematics and an Eagle layout are available at www.potomacmeso.com. We built this setup for wireless sensing applications, but it probably would be useful in other areas where miniaturization is important. If there is enough interest, we may offer this as a product. Right now we’re comp’ing a few of these to advanced users with miniature applications.
Comments and suggestions are always welcome.