loading effect in AVR microcontroller

[Jayk]

I have interface VS-2 servo motor with ATMEGA-32 micro-controller directly to its port.When i apply source to the circuit due to loading effect voltage drops from 5v to 2v.I dont understand the problem. Is there any remedy to problem? My programming is correct.do e need any component in between servo motor and microcontroller?

 

[mrarslanahmed]

some capicitance in series with parallel diode protection. servo is inductive load

 

[Easyrider83]

There are two types of servo exist. Digital and analog.
Digital controls by impulse width. You must send control impulse to servo every 20ms. Minimum 0.8ms, max 2.5ms. Center rotation - 1.8ms.
Analog works simpler, by analog voltage.

 

[alexxx]

do e need any component in between servo motor and microcontroller?

I don't think it is a good idea to directly drive a motor from the MCU's pin.

some capicitance in series

In series with what? The motor?

 

[mrarslanahmed]

in series with motor to balance phase difference created due to motor.....

 

[alexxx]

in series with motor to balance phase difference created due to motor.....

When I searched for this some time ago, I found myriads of references with the capacitor in parallel with the motor. Not a single one with the capacitor in series. Can you google for a reference and post it?

 

[mrarslanahmed]

no need to google it ...... second time u corrected me ..........thankyou

i been thinking phase difference will be balanced via capacitor in series...I WAS WRONG:-(

 

[bigdogguru]

I have interface VS-2 servo motor with ATMEGA-32 micro-controller directly to its port.When i apply source to the circuit due to loading effect voltage drops from 5v to 2v.I dont understand the problem. Is there any remedy to problem? My programming is correct.do e need any component in between servo motor and microcontroller?

Your problem is most likely due to power supply overload due to the excessive current flow from the VS-2 Servo Motor. The VS-2 can easily draw 250mA with no load, under excessive load the VS-2 can draw as much as 1A. These levels of current can easily overload a development board's power supply or DIY supply. I would strongly recommend you drive your servos from a separate power supply, a 5-6v 4A adapter can effectively drive four to five RC servos under heavy loads or six to eight under moderate loads. However make sure to connect the GNDs from the power supplies making them common.

VS-2 RC Servo Datasheet

It is sometimes handy to refer to existing designs for inspiration:

some capicitance in series with parallel diode protection. servo is inductive load

The majority RC servos of recently designs have inductive kick or back EMF protection circuitry, so additional diodes and capacitors are not usually required with most RC servos.

Reference above Cerebot design.


BigDog