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The Digispark => Digispark (Original) Support => Topic started by: alecaksono on March 25, 2017, 02:50:46 am

Title: Help! i cant move my digital servo
Post by: alecaksono on March 25, 2017, 02:50:46 am

hello guys 8) i'm newbie in digispark and coding hehe.
 i have some digital servo jx pdi6221mg http://www.banggood.com/JX-PDI-6221MG-20KG-Large-Torque-Digital-Coreless-Servo-For-RC-Model-p-973947.html
this servo work with 1520us/330hz and it was my code
#include <SoftRcPulseOut.h>
#define NOW             
SoftRcPulseOut servo1;
SoftRcPulseOut servo2;
int pot1 = A2;
int pot2 = A3;

int valPot1;
int valPot2;
void setup()
{
 
  servo1.attach(1);
 
 servo2.attach(0);
 }

void loop()
{
 valPot1 = analogRead(pot1);
 valPot1 = map (valPot1, 0, 1023, 0, 180);
 servo1.write(valPot1);
SoftRcPulseOut::refresh(NOW);


 valPot1 = analogRead(pot1);
 valPot1 = map (valPot1, 0, 1023, 0, 180);
 servo2.write(valPot1);
 SoftRcPulseOut::refresh(NOW);



}

before it, i'm use mg995 the code was work, but for 6221mg it wasnt work,
as i know the softrecpulseout work in 20ms pwm, there is someway to change it from 20ms/50hz to 330hz frequrncy?
or you guys have some trick to move my digital servo

thx for your help.



sorry my english is bad ;D

Title: Re: Help! i cant move my digital servo
Post by: RC Navy on March 26, 2017, 10:27:56 am

Hi,

You can refresh the servo with a custom refresh time by calling SoftRcPulseOut::refresh() with 1 as argument.
This is what is done below by defining NOW as 1:
As the servos are refreshed immediately, you have to wait around 3030 microseconds minus the largest pulse width of the servos in microsecond.

Code: [Select]

#include <SoftRcPulseOut.h>

#define NOW                                                1 // <- Very important to define NOW as 1
#define HIGH_REFRESH_FREQ_HZ    330
#define PERIOD_US                                   (1000000UL /  HIGH_REFRESH_FREQ_HZ)

SoftRcPulseOut servo1;
SoftRcPulseOut servo2;

int pot1 = A2;
int pot2 = A3;

int valPot1;
int valPot2;

void setup()
{
  servo1.attach(1);
  servo2.attach(0);
 }

void loop()
{
 uint16_t LargestPosUs;

 valPot1 = analogRead(pot1);
 valPot1 = map (valPot1, 0, 1023, 0, 180);
 servo1.write(valPot1);

 valPot2 = analogRead(pot2);
 valPot2 = map (valPot2, 0, 1023, 0, 180);
 servo2.write(valPot2);

 SoftRcPulseOut::refresh(NOW); // A single call is sufficient for all the sevos

 LargestPosUs = servo1.read_us();
 if( servo2.read_us() > LargestPosUs) LargestPosUs =  servo2.read_us();

// Wait for around 3030 microseconds minus the largest pulse width
 delayMicroseconds(PERIOD_US - LargestPosUs); // This should warranty a constant period around 3030 microseconds (330Hz)
}

No tested, up to you!

Title: Re: Help! i cant move my digital servo
Post by: alecaksono on March 28, 2017, 10:09:48 am

thanks a lot RC Navy you have write the code for me,
i was check the pulse are 330hz or 3030ms but my servo don't move, 
i get confuse with the digital servo work
i have tested the servo with servo tester its some time work,
i have tested with arduino, i used knob and sweep code from example. with sweep code the servo was work, but with knob code it wasn't work.
i have tested too with rc receiver and its work for 90 degree, beacause the pulse only 1500ms.
what should i do? i have tested your code, make digitalWrite code, even use logic level.

Title: Re: Help! i cant move my digital servo
Post by: alecaksono on March 28, 2017, 10:42:50 am

for additional,

all the tools that I use have been checked using the osciloscope,
and mostly have same signal about 20ms pulse width, and for the rc signal gave 3.3 v output signal
i have used the logic level too for the arduino knob program hope the servo work and yeah its still not work