The ADP5588 demonstration board is used to exercise the features of the ADP5588 keypad/GPIO expander IC. It consists of a daughterboard and a motherboard. The motherboard houses the keypad (80 switches), a USB connector (JP1), a reset switch (S17), and all the hardware necessary to power the IC and establish USB communication with the PC. Two 20-pin connectors (J11 and J12) are used to plug in the daughterboard. The ADP5588 IC is mounted on the daughterboard along with the LK1 and LK2 jumpers, which are used to insert or remove the C19 and C20 capacitors from the light sensor comparator circuitry.
The demonstration board assembly is powered either via J10 or the USB port and comes with a free graphical user interface (GUI) to exercise the ADP5588 features. In addition to the keypad switches, the motherboard also has 18 GPO LED indicators (D1 through D11, D22 through D27, and D30), power status LEDs (D19 and D21), a 2.7 V regulator, a 3.3 V regulator, and jumpers (J1 through J8 and J13 through J22) to configure the GPIOs as GPIs, GPOs, or keypad lines. The motherboard is equipped with jumpers (LK8 and LK10) to configure the board to use either external regulated voltages via J10 or the on-board regulators when plugged into the USB port. When using the USB port as the power source, place jumpers across Pin 1 and Pin 2 of LK8 and LK10. When using external voltages, place jumpers across Pin 2 and Pin 3 of LK8 and LK10. VCC (Pin 3 of J10) should be 1.8 V to 3.0 V, and VBOARD (Pin 1 of J10) should be 3.3 V.