Keep the Servo still, when I plug in the USB

Forum 2005-2010 (read only) Hardware Troubleshooting
1

Hey guys,

I've noticed each time I plug in my USB, the Arduino will kind of freaks (calibrates or whatever it does) and what I have plugged acts up (LED flashes, servo spins in random areas) then it does it program.

Anyways, I want my servo to stay still when I plug in the USB.

Is there anyway to do this?

Thanks!

2

Have you tried different pins? I am not sure of the technicalities of it but maybe it is only on certain pins...

3

Plugging the usb might do a reset to the arduino
Look at the led on pin 13 if it lights up then you might have a problem with the reset and you can try to disable it,(you will have a problem prodraming it)

In one of my arduino's i put a two pin header so i can disable and enable the auto-reset

4

Ya it is resetting (the LED on pin 13 blinks like crazy when I plug the USB)

Can I have more information about programming it not to reset?

5

Can I have more information about programming it not to reset?

No you can't program it not to reset, you can disable the auto reset by disconnecting the capacitor connecting the USB chip to the arduino's reset line.

6

No you can't program it not to reset...

Actually you can. If reset is neither required nor desired you can program the RSTDISBL fuse which will disable external reset and convert it to an IO pin.

7

Its not wise to change. The RSTDISB fuse you need it to program the chip
The best option is to remove the capasitor conected to the reset line (and manualy reset the arduino on upload)

8

I was reading about this somewhere else on here today.

Try a resistor between the arduino and and servo, it should remove the noise generated on reset but let actual commands go through.

9

Let us know if it works, it sounds rubbish to me.

10

I think that it was a pull-down, rather than "between", which implies series connection to me.

11

The RSTDISB fuse you need it to program the chip

Reset is not needed for programming with a bootloader (a power off/on cycle synced to upload can be used to start the bootloader). You may however "desire" it.

12

I think that it was a pull-down, rather than "between", which implies series connection to me.

I stand corrected.

13

Its not wise to change. The RSTDISB fuse you need it to program the chip
The best option is to remove the capasitor conected to the reset line (and manualy reset the arduino on upload)

So if I cut the capacitor, can I reset the audrino from my computer or do I always have to press the reset button?

My Arduino is going to be in a place that will be extremely hard to press the button, but I plan on connecting and disconnecting the USB to the arduino frequently.

Also....
How do I cut the capacitor? Is the thing left of 'RESET-EN'? Can I take a knife and score the little metal line between the two metal lumps?

14

Found a guide on Disabling AutoReset
http://www.arduino.cc/playground/Main/DisablingAutoResetOnSerialConnection