BS2p icon (BS2p40)





Syntax: MAINIO


Switch from control of auxiliary I/O pins to main I/O pins (on the BS2p40 only).

Quick Facts

  BS2p / BS2pe / BS2px
I/O Pin IDs 0 - 15 (just like auxiliary I/O, but after MAINIO command, all references affect physical pins 5 - 20).
Special Notes

Command is accepted by the 24-pin BS2p, BS2pe, and BS2px, but only the 40-pin BS2p40 gives access to the auxiliary I/O pins.

Related Commands



The BS2p, BS2pe, and BS2px is available as a 24-pin module that is pin-compatible with the BS2, BS2e, and BS2sx. Also availabe is a 40-pin module called the BS2p40 with an additional 16 I/O pins (for a total of 32). The BS2p40's extra, or auxiliary, I/O pins can be accessed in the same manner as the main I/O pins (by using the IDs 0 to 15) but only after issuing an AUXIO or IOTERM 1 command. The MAINIO command causes the BASIC Stamp to affect the main I/O pins (the default) instead of the auxiliary I/O pins in all further code until the AUXIO or IOTERM 1 command is reached, or the BASIC Stamp is reset or power-cycled.

The following example illustrates this:

  HIGH 0
  LOW 0

The first line of the above example will tell the BASIC Stamp to affect the auxiliary I/O pins in the commands following it. Line 2 sets I/O pin 0 of the auxiliary I/O pins (physical pin 21) high. Afterward, the MAINIO command tells the BASIC Stamp that all commands following it should affect the main I/O pins. The last command, LOW, will set I/O pin 0 of the main I/O pins (physical pin 5) low.

Note that the main I/O and auxiliary I/O pins are independent of each other; the states of the main I/O pins remain unchanged while the program affects the auxiliary I/O pins, and vice versa.

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