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About Servo library

FTinetti
Honored Contributor I
1,758 Views

Hi,

I've used the Arduino Servo library,

https://www.arduino.cc/en/Reference/Servo Arduino - Servo

which has two attach() functions https://www.arduino.cc/en/Reference/ServoAttach Arduino - ServoAttach :

servo.attach(pin)

servo.attach(pin, min, max)

I see that Intel Galileo Servo has other two attach functions:

uint8_t attach(int16_t pin, bool force48hz = false); // attach the given pin to the next free channel, sets pinMode, returns channel number or 0 if failure

uint8_t attach(int pin, int min, int max, bool force48hz = false); // as above but also sets min and max values for writes.

I assume (correct me if I'm worng) that the "force48hz" parameter would be for setting PWM period, but I would like to know why it is necessary in Galileo...

TIA,

Fernando.

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5 Replies
idata
Community Manager
141 Views

Hi Fernando,

 

 

If the force48hz argument is set to true, the initial frequency will be 48Hz; otherwise 188Hz is assumed. The other argument, called pin, only specifies the PWM pin to be used to emit the pulse signals to the servo.

 

 

-Sergio

 

FTinetti
Honored Contributor I
141 Views

Thank for replying, Sergio,

I would like to know why it is necessary in Galileo...

.. because it is not the way it's implemented and used in Arduino... why the change? Furthermore, is 188Hz the Arduino default?

Fernando.

idata
Community Manager
141 Views

We'll investigate and post a reply soon.

 

 

-Sergio

 

idata
Community Manager
141 Views

Hi Fernando,

 

 

Thank you for your patience. The libraries are expected to be different as the architecture of the boards is different. As for your question, the Arduino UNO has a frequency of approximately 490 Hz in most pins (3, 9, 10 and 11) and a frequency of approximately 980 Hz in pins 5 and 6, this information can be found here https://www.arduino.cc/en/Reference/AnalogWrite https://www.arduino.cc/en/Reference/AnalogWrite

 

 

-Sergio

 

FTinetti
Honored Contributor I
141 Views

Hi Sergio,

Thank you,

Fernando.

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