Data Sheet

4
COMPONENT DESCRIPTION
The top 40 pin header plugs into the Raspberry Pi GPIO header and passed through the pins to the next
MEGA-IO expansion card.
The eight relays are numbered from upper left to lower right. Numbering the Relays is important to
associate them correctly with the Relay Headers and Relay LEDs. The Relays are SPST, with three output
pins labeled COM, NO and NC.
The Relay LEDs are right angle, to permit visual inspection of the relays status when multiple cards are
stacked.
CONFIGURATION JUMPERS
Stack Level. Three jumpers permit addressing multiple MEGA-IO cards on the I2C bus. No jumpers need
to be installed if only one card is present. If two or more cards are stacked up, the card is addressed as
follows:
ID Jumper
000
001
010
011
100
101
110
111
Stack level
1
2
3
4
5
6
7
8
I2C Address
0x20
0x21
0x22
0x23
0x24
0x25
0x25
Ox27