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Electronics => Electronics => Topic started by: Canabots on March 05, 2009, 05:54:10 PM

Title: Micro Servo Issue
Post by: Canabots on March 05, 2009, 05:54:10 PM

Hi all!

I just bought 2 micro servos from raidentech.com (the 8g ones). So I plug it into a test circuit, but all I got from the servo is a faint hum (occasionally). So I tried my Standard HS-311 servo, and the test ran perfectly.

Upon inspection to the servo, there's a label saying "Digital Servo  E-Sky  EK2-0508"

How different is the control of a digital servo from an analogue one? Will I have to get one of those special programmers? :-[

Here's the code on the PIC:

Code: [Select]

#include <pic.h>
#include "delay.h"

__CONFIG(INTIO & WDTDIS & PWRTEN & MCLRDIS & UNPROTECT
 & BORDIS & IESODIS & FCMDIS);

int j,i,k;

main()
{
TRISA = 0b111110;


while (1)
{
for(j=0;j<250;j++)
{
RA0 = 1;
DelayUs(250);
DelayUs(250);
DelayUs(250);
RA0 = 0;
DelayMs(18);
}
for(j=250;j>0;j--)
{
RA0 = 1;
DelayMs(1);
RA0 = 0;
DelayMs(18);
}
for(i=0;i<250;i++)
{
RA0 = 1;
DelayMs(1);
DelayUs(250);
DelayUs(250);
RA0 = 0;
DelayMs(18);
}
for(i=250;i>0;i--)
{
RA0 = 1;
DelayMs(2);
RA0 = 0;
DelayMs(18);
}
for(k=0;k>250;k++)
{
RA0 = 1;
DelayMs(2);
DelayUs(250);
DelayUs(100);
RA0 = 0;
DelayMs(18);
}
}
}

Thanks in advance for any help! :)

Canabots

Title: Re: Micro Servo Issue
Post by: Razor Concepts on March 05, 2009, 06:23:23 PM

Digital servos take the same signals as analog servos.

Servos from raidentech are of poor quality, you might have received a dud.

Title: Re: Micro Servo Issue
Post by: Canabots on March 05, 2009, 07:29:47 PM

Quote from: Razor Concepts on March 05, 2009, 06:23:23 PM

Digital servos take the same signals as analog servos.

Servos from raidentech are of poor quality, you might have received a dud.

uhoh, that's not good :'(

Are the signal ranges maybe higher or lower than analog servos (as in, instead of say 1 ms, maybe .5ms? Or instead of 2ms maybe 2.5ms?)

I suppose that if worst comes to worst I can salvage the motor and gearbox from the servos, but I'd rather try as much as possible before doing anything like that.


Quick Edit: I found this (http://www.futaba-rc.com/servos/digitalservos.pdf (http://www.futaba-rc.com/servos/digitalservos.pdf)) describing the control of a digital servo. Does anyone know what sort of timing the pulses require for the servo to move?

Thanks