RC Servo control

Design Concepts
1

well, I have read a lot of threads about PWM and stepper motors and so on, but I couldnt find an final answer that helps me to answer my next question.

I like to control some RC servos with the MB64. That means the DOUT have to output an PWM signal.

I’ts not really highspeed clocked … every 20ms a pulse of 1ms (min. value) to 2 ms (max.value).

I have read that PWM needs very much performance, but I dont know if this relative slow PWM is also too much for an PIC (in the case that there are 4 to 16 such PWM needet). And finaly I have no idea how I could programm such a PWM “option”  ::).

someone tried this ?

any hints ?

Thanks

e-toy

2

Ahhh PWM… It’s like the $64000 question around here lately!

There’s a PWM peripheral on the PIC, has anyone aside from TK used it and feels like explaining it to us all? I’ve got a rough idea, so I’ll step up and learn the rest if needed… But I don’t want to reinvent the wheel if someone already knows :wink:

Anyhow, that’s just the one output, not 4-16, so I don’t know if this is the right way to go for you e-toy.

3

where is my post about aout and ne555 ???

out of topic  ???

4

Sorry mate you replied to a crosspost&hijack (not your fault) and I had to do a cleanup… It’s : Re: Organ Swell Shades Control

5

I have read that PWM needs very much performance, but I dont know if this relative slow PWM is also too much for an PIC (in the case that there are 4 to 16 such PWM needet). And finaly I have no idea how I could programm such a PWM “option” 

someone tried this ?

any hints ?

Check this :

http://www.hobbyengineering.com/H1591.html

http://www.crownhill.co.uk/product.php?prod=1267

(looks very interesting, i ordered one!)

I plan to try it, but maybe only after my mbhp stepper motor driver :slight_smile:

6

I plan to try it, but maybe only after my mbhp stepper motor driver Smiley

Another project you working on I`m very interested in. :slight_smile:

7

I like to control some RC servos with the MB64.

Hmm, i wonder : what do you plan to do with servos ?

(i just received my i2c servo driver… stay tuned :wink:

8

I have this document : http://www.roboter-teile.de/datasheets/sd20.pdf

can someone translate this to me :

Das ist der Einschaltzustand. Der Stellbereich geht von 1ms bis 2ms bei 1,5ms Mittelstellung

(entspricht der RC-Modellbau Spezifikation). Um in den Standard Modus zurückzukommen

(falls zuvor in den erweiterten Modus gegangen wurde), muss eine 0 (Null) in das Reg 21

geschrieben werden. Werte von 1 - 255 (0x01 - 0xff) im Reg 21 schalten in den Erweiterten

Modus.

I dont understand a german word, and google translator didn’t help me much :frowning:

Should i write something to register 21 before i can use standard mode ?  :-\

9

Hi Bill,

it sais:

This is the state when switched “on”. Selectable values range from 1ms to 2ms (1.5ms middle) like the RC-model specification). When the extended Mode has been selected, you can switch back to standard mode by writing a 0 (zero) to register 21. Values from 1 - 255 (0x01 - 0xff) in register 21 switch to extended mode

Hope this helps :wink:

Best,

Michael

10

Thank you Michael  ;D