L A B  4  C O D E

s e r v o   c o d e  

' Code for Servo Motor
DEFINE OSC 4
DEFINE  ADC_BITS        10   ' Set number of bits in result
DEFINE  ADC_CLOCK       3       ' Set clock source (3=rc)
DEFINE  ADC_SAMPLEUS    10      ' Set sampling time in uS

TRISA = %11111111       ' Set PORTA to all input
ADCON1 = %10000010      ' Set PORTA analog and right justify result
TRISD = %00000000  'Set PortD to all OUTPUT
TRISC = %10000000 ' SET PORT C SERIAL IN on PORTC.7 and out on C.6

ADCvar  VAR WORD
ylLED   VAR PORTD.0
pulseWidth var WORD
pulseRange VAR WORD
servo_1 VAR PORTC.3
txPin VAR PORTC.6

' set up constants with the minimum and maximum pulsewidths
minPulse CON 50
maxPulse CON 250

' set up a constant with the time between pulses:
refreshPeriod CON 20

pulseWidth = minPulse 'initial pulse width

pulseRange = maxPulse - minPulse

PAUSE 500

GOSUB blink

main:
   ADCIN 0, adcVAR
   ' check value on scree with serial out
   serout2 txPin, 16468, ["my adcvar = ", DEC ADCvar, 13, 10]

       Low servo_1  'make output pin low so we can pulse it high

       PulsOut  servo_1, pulseWidth  ' PULSE THE SERVO PIN

       Pause refreshPeriod

       IF pulseWidth > maxPulse Then
               pulseWidth = minPulse    ' change back to min to start over
       Else
               pulseWidth = minPulse + (pulseRange * (ADCVAR/10))/100

       Endif
GOTO main