Arduino Mega Output pins go HIGH after reset - problem

Development Tools IDE 1.x
1

Hello guys ;D I tried searching in the forum first but it was hard to find something usefull.

So I have a project where I input signals to a motor and I read some data from it.
I am using simulink and everytime I start a simulation to send the signal to the arduino the arduino resets like when it does when you open the terminal ide.

The thing is that when it resets all inputs go HIGH and the motor starts to spin at 100% power which is unwanted.

How could I erase this feature ? I heard that it comes with the bootloader, is there any point to it ? is it essential for the arduino to function correctly?

If not how can I disable it?
#####EDIT######
I found that I could use a capacitor 22uF at the reset pin so it wont reset when I connect to arduino to send new signals but I think this would be a lazy man fix that wouldnt really fix it anyway.

I have an arduino mega 1280.
Thanks in advance guys :wink:

2

The thing is that when it resets all inputs go HIGH and the motor starts to spin at 100% power which is unwanted.

How could I erase this feature ? I heard that it comes with the bootloader, is there any point to it ? is it essential for the arduino to function correctly?

The problem is not with the arduino but rather the motor controller's input circuitry. At reset all arduino I/O pins go input mode, high impedance which will be seen as a 'floating input' on any of the motor driver's input pins. Wire a 10k ohm pull-down resistor on each motor control input pins should control the problem.

3

That never crossed my mind, it worked like a charm.

Thank you very much !!