Even upmarket digital multimeters with a built-in capacitance function are useless if you want to check out tiny capacitances, such as 2.7 pF or 5.6 pF. Usually the lowest measuring range is 2000 pF, which is a joke for RF designers and radio amateurs. Although the resolution of a 3.5-digit DMM resolution is 1 pF at this range setting, measurements below 200 pF or so yield results that are rough at best and ridiculous at worst.
This where Pico C comes to the rescue. Beating many DMMs hands down, this instrument easily measures capacitances down to fractions of a picofarad. Based on an ATtiny2323 microcontroller and an LCD module, it has a measuring range extending from below 1 pF to 2000 pF (guaranteed), or even as much as 2500 pF, with a resolution of 0.1 pF.
Readings are displayed on a two-line LCD module.
A full kit for this instrument is available from the Elektor Shop. It features low cost and easy assembly (no SMDs). All source code and hex code are available for free download.
Note: shipping is free for orders placed by 15 June 2011, and the first 100 kits include a free 1000 pF 1% reference capacitor to simplify calibration.