Hi, i'm experimenting some issues with my Arduino Industrial 101. I couldn't find good info about the board, but it seems to have 20 I/O pins (7 on header). What are the "on header pins" used for? I have tried to use the D0-D7 pins to turn on and turn off a 8 channels 5V relay, but i don't understand how they work. When i write them as HIGH, the relays connected to pins D1 and D2 turn on at the same time, and the only pin that "works" correctly is the D1, i don't know why. The D2 pin turns on too. But, the others don't turn on even when i use the digitalWrite function and put them to HIGH. I expect someone knows how this board works and if there is a solution to make the I/O's work fine.
Thank you. Greetings!