analoge outputs and servo motors possible?

[intosite]

Has it been done before? A midi out that sent analoge output signals or control a servo motor?

Cheers

[Steven_C]

a motorised fader is basically a servomotor  ;)

[intosite]

Ah, I was suspecting so..

Am new to electronics.

[Guest Zzzz...]

Yep...

Just tested mine MF_unit with 8 servo motors connected to it...but

somehow i wasn't able to let the servo motors turn both sides. ie..

forward and backwards...

Only one side turning works (depending on how you connect the motorfader), but don't know if this is also what happens with the actually motorfaders...(or is it working with two motors?)...

Does anybody know if the microship tc4427 should "flip" the voltage?

Or does anyone have a answer to my question?

Thanks in advance...

Erik

[smashtv]

The words servo motor are thrown around a lot in electronics, but it's usually used to describe a DC motor with a connected pot or encoder to feed position information back to the motor controller.

There are large high-torque units (like I use with CNC) and small units (like a motorfader).  RC servos are a slightly different breed since they have the motor controller built in, and read a PWM signal to go to position.

That said, what kind of servo motor are you wanting to run from the AOUT?

Drive of RC servos (like futuba) from the AOUT should be fairly easy with a small circuit that changes voltage level to PWM.  I have a schematic for this somewhere but I'll have to dig it up.

On the TC4427, It does flip the voltage to throw the the motor in reverse.  This won't make the average RC servo happy though!

Have fun!

SmashTV

[Guest Zzzz...]

Thanks....Smash

for all the documentation....I use now (probably) rc motor stolen from a cd player...open/close (eject) but this wil not react to the reverse...if i raise the midi-out cc note's (in Max ctlin from 0 to 127)...what could be wrong?

Some problem with the diodes stuffed...only able to forward not reverse?

Thanks for the advice...

Some advice about which motors to buy, but not for as use as motorfader, but some (driving + walking) robot?

Erik

[TK.]

Hi Erik,

it's important to know such details... ;-) although you haven't it meantioned here, yet, I guess that you need to add a pot which is directly coupled with the motor, because the MF driver moves the motor into one direction until the target position (or in other words: the target output voltage of the pot) is reached.

You could easily test if the motor runs also into another direction by toggling the appr. analog input pin between 0V and 5V

Best Regards, Thorsten.

[Guest Zzzz...]

Hi Thorsten....

Thanks for your reply.... as I already was thinking this...you have to connect the analogue input voltage (ie faders/pots)for the positioning of the motors...and this probably the best thing to do if you want to have a motorfader which you want to move virtually or physically.

But there's no way to work around the pots or the analogue inputs? Do I really need the pots or is there some way to rewrite the code of the pic and let the voltage change by some code over time and midi...I mean..

From 0 -127 in 0 -10 sec or so? on a linear scale?

a kind of time(as virtual voltage)-midi-matrix?

Or is that really much work..?

Hope this is clear...

Thanks ...

Erik

[TK.]

Hi Erik,

Of course, this is a lot of effort, especially for somebody who never would use such a "toy" feature by himself. The implementation is easier than writing a motorfader driver, but I see no benefit, so - no support from my side.

You know, MIOS is open source - take a look into mios_mf.inc, and change it like you want, or ask other people for help

Best Regards, Thorsten.