Continuous rotation servo v2.0

BASIC Stamp Calibration Code - for all BS2 models

√ Connect the servo to BASIC Stamp 1/O pin P12, or update the ToServo PIN declaration.

√ Run the program, and gently twist the potentiometer adjustment screw until the servo does not

turn or vibrate.

NOTE: Calibrating the servo may take some patience. The potentiometer is very

sensitive so a very light touch will be required.

' {$STAMP BS2}

' {$PBASIC 2.5}

#SELECT $Stamp

#CASE BS2, BS2E, BS2PE ' PULSOUT Duration units are 2 us for these models

Center CON 750

#CASE BS2SX, BS2P, BS2PX ' PULSOUT Duration units are 0.8 us for these models

Center CON 1875

#ENDSELECT

ToServo PIN 12 ' connect servo to I/O pin P12, or change it here

PULSOUT ToServo, Center ' ToServo pin outputs 1.5 ms pulse

PAUSE 20 ' refresh pulse every 20 milliseconds

LOOP

Propeller Chip Calibration Code – for P8X32A

√ Download and unzip the Propeller code file from the 900-00008 product page.

√ Connect the servo line to pin 0.

√ Run the program CenterServo.spin, and gently twist the potentiometer adjustment screw until

the servo does not turn or vibrate.

NOTE: Calibrating the servo may take some patience. The

potentiometer is very sensitive so a very light touch will be required.

CenterServo.spin

CON

_clkmode = xtal1 + pll16x ' System clock → 80 MHz

_xinfreq = 5_000_000

PUB CenterServo | tInc, tc, tHa, t

ctra[30..26] := %00100 ' Configure Counter A to NCO

ctra[8..0] := 0

frqa := 1

dira[0]~~

' Set up cycle and high times

tInc := clkfreq/1_000_000

tC := tInc * 21_500

tHa := tInc * 1500

t := cnt ' Mark counter time

repeat ' Repeat PWM signal

phsa := -tHa ' Set up the pulse

t += tC ' Calculate next cycle repeat

waitcnt(t) ' Wait for next cycle