As the Raspberry Pi wasn't originally intended for the multitudes of hardware applications that have befallen the popular single-board computer, it misses out on a few convenient features such as an analogue-to-digital converter. However you can easily add your own with one of the many options that have been documented, and one of those is by Instructables member AntMan232 who uses a PICaxe 28X1 PIC-based microcontroller.
As the PIC can communicate via I2C, and has four ADCs - it's a neat solution to the problem. It can easily communicate the values from the ADCs back to the Pi and using simple python code the values can be integrated into local software.
Every day we find more uses for our PiBreak board, such as the ADC project above - which makes the PiBreak a great way to mount circuitry to your Raspberry Pi. It provides labelled breakout pins for all GPIOs, a large prototyping area with solder pads, and power rails for easy power connection:
Furthermore the PiBreak also includes mounting hardware to firmly attach it to your Raspberry Pi using a nut, bolt, and spacer - and is compatible with all revisions of both model A and B Raspberry Pi computers. For more information about our new PiBreak board, our Getting Started guide, and to order - visit the product page.