Servo motors are not really friendly. -alex
Nanna - Oops, sorry I realized I forgot to post things on the labs page. Everything I do gets continually documented in my journal: Nanna's Journal
Chris - I had a hard time getting my head around pulsing the servo motor. I got frustrated because I wanted to know what the pulse looked like and how the servo used the pulse. I broke out the oscilloscope and took a look. It was worth it. 5v's On or Off. I like oscilloscopes. I still don't know how the servo uses that pulse, exactly. I wired in a pot that determines the 'throw' of the motor - the closer to zero it is the bigger the throw, and the closer to 255, the less the motor moves. I also tried some PWM with LEDs?. I could get them to ramp up, but not in the right order/timing I was looking for. I focused too much on both pulsing the servo and PWMing? LEDs? that I didn't get to FREQOUT, which is a bummer. I wanted to make some tunes.
Shiu-Feng - hm....I need more time working with code... :( week4
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- Rolf:
October 6, 2005
Analog Output: Servo Control using a potentiometer
Enclosed is the code and a diagram
Code:
DEFINE OSC 4
DEFINE adc_bits 8
define adc_clock 3 'internal clock
DEFINE adc_sampleus 20 'check input
adcon1 = %00000010
trisa = %11111111
OUTPUT portd.0
PulseWidth?? VAR BYTE 'info for the servo motor
PulseMax?? CON 250 '=180 degree
pulseMin CON 50 '= start at 0 degree
RefreshPeriod?? CON 20
adcVar VAR BYTE
ServoSpeed?? VAR BYTE
start:
HIGH portd.0
Pause 500
low portd.0
PAUSE 500
HIGH portd.0
PAUSE 500
LOW portd.0
PulseWidth?? = pulseMin
main:
ADCIN 0, adcVar
ServoSpeed?? = adcVar/16
LOW portd.1
PULSOUT portd.1, PulseWidth??
PAUSE RefreshPeriod??
IF PulseWidth?? > PulseMax?? THEN
pulseWidth = pulseMin
ELSE
PulseWidth?? = PulseWidth?? + ServoSpeed??
Endif
GOTO main
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Jury Hahn