# REVERSE Examples

{PBASIC 2.5}

Example

Connect an LED and two resistors as shown below for the demo program.

    ' REVERSE.BS1
    ' Connect the circuit shown in the REVERSE command description to I/O pin
    ' 0 and run this program.  The LED will alternate between two states, dim
    ' and bright. The BASIC Stamp is using the REVERSE command to toggling I/O
    ' pin 0 between input and output states. When pin 0 is an input, current
    ' flows through R1, through the LED, through R2 to ground. Pin 0 is
    ' effectively disconnected and doesn't play a part in the circuit. The total
    ' resistance encountered by current flowing through the LED is R1 + R2 = 1220
    ' ohms. When pin 0 is reversed to an output, current flows through R1, through
    ' the LED, and into pin 0 to ground (because of the 0 written to PIN0). The
    ' total resistance encountered by current flowing through the LED is R1,
    ' 220 ohms. With only 20% of the resistance, the LED glows brighter.

    ' {$STAMP BS1}
    ' {$PBASIC 1.0}

    Setup:
      PIN0 = 0                              ' Put a low in the pin 0
                                            '  output driver
    Main:
      PAUSE 250                             ' 1/4th second pause
      REVERSE 0                             ' reverse pin 0 I/O direction
      GOTO Main                             ' do forever

NOTE: The example below is written for the BS2 and will run on any of the BS2-family modules. Modify the $STAMP directive (as required) before downloading to the BS2e, BS2sx, BS2p, BS2pe, or BS2px.

     REVERSE.BS2
    ' Connect the circuit shown in the REVERSE command description to I/O pin
    ' 0 and run this program.  The LED will alternate between two states, dim
    ' and bright. The BASIC Stamp is using the REVERSE command to toggling I/O
    ' pin 0 between input and output states. When pin 0 is an input, current
    ' flows through R1, through the LED, through R2 to ground. Pin 0 is
    ' effectively disconnected and doesn't play a part in the circuit. The total
    ' resistance encountered by current flowing through the LED is R1 + R2 = 1220
    ' ohms. When pin 0 is reversed to an output, current flows through R1, through
    ' the LED, and into pin 0 to ground (because of the 0 written to OUT0). The
    ' total resistance encountered by current flowing through the LED is R1,
    ' 220 ohms. With only 20% of the resistance, the LED glows brighter.

    ' {$STAMP BS2}
    ' {$PBASIC 2.5}

    Setup:
      OUT0 = 0                              ' Put a low in the pin 0
                                            '  output driver
    Main:
      PAUSE 250                             ' 1/4th second pause
      REVERSE 0                             ' reverse pin 0 I/O direction
      GOTO Main                             ' do forever

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BASIC Stamp Help Version 2.5.4

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8/8/2012