Sending 17 PWM at once cause Roboard reboot?

[Tsai Sung Yang]

Code: Select all

for (int ch = 0; ch < 21; ch++)
{
    if (ch==4||ch==8||ch==9||ch==15) // Unused Channel
        continue;

    rcservo_SendPWMPulses(ch, PWM_period, PWM_duty[ch], count);
}


I sent 17 PWM channels at once to control my KONDO KHR-2HV, but it cause Roboard often automatically reboot. I used 9V 4A adapter.
Is that due to not enough Ampere?

[PaulL]

I would guess not enough amperes. To verify, you can try the code without the servos attached. I would think that you need more than 4 amperes to run 17 servos. The roboard uses about 500 mA, so you have 3.5A for servos, that's around 200 mA per servo. You could also try moving fewer servos at one time to test.

You can also try a lower voltage that would induce lower amp draw.

[Tsai Sung Yang]

Code: Select all

//you need to change this function for Linux and DOS
private: System::Void wait_ms(unsigned long ms)
{
  unsigned long nowtime = GetTickCount();
  while ((GetTickCount() - nowtime) <= ms);
}

for (int ch = 0; ch < 21; ch++)
{
    if (ch==4||ch==8||ch==9||ch==15) // Unused Channel
        continue;

    rcservo_SendPWMPulses(ch, PWM_period, PWM_duty[ch], count);
    delay_ms(1);
}



This is a little trick I come through with not enough amphere.

[copperclad]

Hi Tsai
thanks for posting . cool solution for the servos startup surge

.