EXPAND 3 click carries DS2408, an 8-channel programmable I/O expander that communicates with the target board MCU through a standard Dallas Semiconductor 1-Wire interface (15.3 kbps or 100kbps). The chip also has a factory-lasered 64-bit registration number, which enables multiple EXPAND 3 clicks to be connected on the same data line. For this purpose, the click has additional three pins above the mikroBUS socket. As for the socket, the onboard GP SEL jumper allows you to specify the communication pins (either OW1 or OW0, which are in place of the usual AN and PWM pins on mikroBUS). An additional reset line (RST) is also connected. The board is designed to use either a 3.3V or 5V power supply.