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Servo
Posted: Fri Feb 05, 2010 12:38 pm
by Jan Lichtenbelt
An interesting new future are the servo's. There is even an possibility to trim the servo's. My experience is that trim at both limits of the servo (left and right) can be necessary. What does the flowcode trim? Changing the all the posotions with the trim-values?
Remark: Do not connect a servo direct to an E-Block output! The initial current on changing position can be to high. My proposal is to test first 1kOhm resistance in the control line.
Re: Servo
Posted: Fri Feb 05, 2010 4:28 pm
by Benj
Hi Jan
The trim value in Flowcode is a method to try to centre the servo which in effect allows you to shift the entire scale of the servo output.
Servos connected directly to a microcontroller output are ok. The current given to the servo motors all comes in via the +V connection and the output from the microcontroller simply operates the closed loop controller. At least I think this is the way they work

Re: Servo
Posted: Mon Feb 08, 2010 10:57 am
by Jan Lichtenbelt
The current/power necessary a servo will go through the +V (red) and Gnd (black) and will strongly depends on the application. The servo will be controlled by a 1-2 msec pulse repeated with 50 Hz. This control line (mostly the white wire) must have enough power for the control unit in the servo. I measured once that the initial current which is (far) above the specifiactions of output of PIC's. That was the base of my advice to use a resistance in this line.
But if you say that it is possible to connect servo's direct to PIC, I'm happy! That is much easier.
Re: Servo
Posted: Tue Feb 09, 2010 1:54 pm
by Benj
Hello Jan
I've not come across a servo motor yet that cannot be ran directly from an I/O pin.
Maybe larger servers like industrial motors eg non R/C would require a larger current on the control line.