Raspberry Pi is a credit card-sized computer of high capabilities and decent price. In addition, it runs under the supervision of a reliable Linux operating system, that makes it ideal for running dedicated, custom projects. Its only disadvantage lies within interfacing dedicated hardware peripherals - and we found a way.

Nowadays, the success of the product consists of such factors as:

  • reliability
  • scalability
  • rapid prototyping
  • decent price

These features are combined by Raspberry Pi.


First of all it depends on the designed control. If you want it to be a simple module that meets only a few features, coding is not sophisticated, then usually a cheap, simple microcontroller is an ideal option. If the design is more sophisticated - or incorporates a bunch of peripherals - then unquestionably the best is a computer, such as Raspberry Pi. The advantage of the operating system is primarily the fact that there is no need to design and coding drivers for peripheral devices (such as displays, storage media), and communication protocol stacks. The designer has only to code an appropriate algorithm, performing a design- specific function. Because Linux is open source with a very rich variety of libraries, it gives you almost unlimited possibilities.


While our prototyping & designs on Raspberry Pi, we quickly exhausted the hardware possibilities of the computer. The have encountered a following problems:

  • limited number of GPIO outputs
  • incompatibility of logic voltage levels (yet plenty of devices operate on 5V, while modern electronics - such as Rasbperry Pi - uses the voltage of 3.3V)

We have developed the Ultimate Expansion Module. Ultimate card incorporates forty-eight (!) Programmable input / output lines compatible with both standards of 3.3V & 5V. It was developed to extend the Microchip MCP23S17 systems and voltage level converters. In addition, equipped with a connector for the TFT display with SPI bus, so we can have for the price of extra few (dozen) of dollars to build a stand-alone computer.