Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: olyke1 on December 21, 2009, 07:58:11 AM

Title: rc to analog speedcontrol (0 to 5 Volts)
Post by: olyke1 on December 21, 2009, 07:58:11 AM

Hello,

I am a newbee. I am using regular DC motors with RC controll and a sabertooth motorcontroller. I would like to change to motors with an analog 0 to 5 Volt speedcontroller (2,5 V is neutral, 5V is full forward and 0 Volt is full backwards). Is it possible to go from servo controll to analog signal including the tanksteering capability?

Greetings, Henk

Title: Re: rc to analog speedcontrol (0 to 5 Volts)
Post by: Soeren on December 21, 2009, 08:08:38 AM

Hi,

Quote from: olyke1 on December 21, 2009, 07:58:11 AM

(2,5 V is neutral, 5V is full forward and 5 Volt is full backwards). Is it possible to go from servo controll to analog signal including the tanksteering capability?

Yes, anything is possible with electronics... If you know how.

What is your level in electronics? Can you read a schematic, can you solder, do you know basic components etc.?
We allready established you can't distinguish a "0" from a "5"  ;D  But the rest we need to know.

Do you really want an analog voltage out? PWM is so much more efficient!
Bob Blick allready made a Servo Pulse to PWM converter (http://www.bobblick.com/techref/projects/sv2pwm/sv2pwm.html).

Title: Re: rc to analog speedcontrol (0 to 5 Volts)
Post by: olyke1 on December 21, 2009, 08:30:28 AM

Hello Soeren,

Thanks for your quick reply. I already changed my mistake with the 5 volts.

I know more then basic electronics and know how to solder and reading schematics.
I have build some simple robots and this will be me first big robot (over 100 pounds).
I have some strong motors but it is with the analog speedcontrol.
I can spent some money so the solution don't have to be cheap.

Greetings, Henk

 

Title: Re: rc to analog speedcontrol (0 to 5 Volts)
Post by: ed1380 on December 21, 2009, 08:53:20 AM

this might not be exactly what you're looking for, but look into an ESC. it is a motor driver that runs off servo pulses.

Title: Re: rc to analog speedcontrol (0 to 5 Volts)
Post by: Soeren on December 21, 2009, 02:14:56 PM

Hi,

Quote from: olyke1 on December 21, 2009, 08:30:28 AM

I know more then basic electronics and know how to solder and reading schematics.
I have build some simple robots and this will be me first big robot (over 100 pounds).

Great, are you comfortable around microcontrollers as well then?

Basically, there's 2 options:
- A microcontroller with D/A-converter can read the pulses, determine their length and then convert it to an analog voltage and output it.
- A couple of Sample&Hold circuits and a few op-amps (for analog computing and level conversion) can accomplish the same, but will take more real estate.