The uCurrent is a precision instrument made by Dave Jones that is able to measure very low currents and feed them as a voltage to be read by a voltmeter.
Electronic instruments that are operated by batteries usually have a customizable interval after which they turn off in order to conserve power. This is one of the features this module brings to the instrument. The default coin-cell slot is removed and my circuit will provide power to the uCurrent from a much beefier 18650 3.7V LiIon cell. A precision 16bit analog to digital converter based on ADS1110 can be used to sample the output and send it to the user via serial UART/bluetooth SPP.
A simple menu is present on the serial connection and it allows the user to calibrate the ADC, get the current readout, configure time intervals until the device goes into sleep mode and save/load the settings into flash.
Although the button is a soft-power one during the sleep mode the current consumption is zero.
Both the hardware and the software are licensed as Open Source