CTIN 534

'{$STAMP BS2}

'BASIC STAMP 2 FIRST PROJECT - COMMUNICATION WITH MAX/MSP

'WHAT SHOULD HAPPEN:
'When a serial message is received on pin 2, the light is turned on or off.
'When the switch is opened or closed, a serial message is sent out on pin 3.

'NOTE: after downloading this program, remove the programming cable from the
'Mac serial port, and plug in the custom serial cable to communicate with Max/MSP.
'Also, you will have to quit out of MacBS2 (or Virtual PC) before you run Max/MSP.

'DECLARE INS & OUTS
input 0 'switch
output 1 'relay
input 2 'BS2 serial receive, mac TXD (transmit)
output 3 'BS2 serial transmit, mac RXD (recieve)

'DECLARE VARIABLES
prevSwitchState var bit
serButtonByte var byte 'serial input from Mac - 1 for button down, 2 for button up

'INITIALIZE VARIABLES
prevSwitchState = 0 'start with switch off

'MAIN LOOP

TOP:
serIn 2,16468,50,CHECKSWITCH,[serButtonByte] 'branch to CHECKSWITCH if 50 ms pass
if serButtonByte = 2 then LIGHTON
if serButtonByte = 1 then LIGHTOFF

CHECKSWITCH:
if in0 <> prevSwitchState then ONOROFF 'branch if switch state changed
goto TOP

LIGHTON:
high 1 'turn on light
'debug "Light ON",cr
serOut 3,16468,["light_ON_"] 'report light on
goto TOP

LIGHTOFF:
low 1 'turn off light
'debug "Light OFF",cr
serOut 3,16468,["light_OFF"] 'report light off
goto TOP

ONOROFF:
if in0 = 1 then SWITCHON 'if 1 then switch on
if in0 = 0 then SWITCHOFF 'if 0 then switch off
goto TOP

SWITCHON:
prevSwitchState = 1
'debug "Switch ON",cr
serOut 3,16468,["switch_ON"] 'report switch on
goto TOP

SWITCHOFF:
prevSwitchState = 0
'debug "Switch OFF",cr
serOut 3,16468,["switchOFF"] 'report switch off
goto TOP