Removing the auto reset in Bare Bones Board Arduino

I’m currently working on a project that requires the Arduino to accept serial input from my mac. This would ordinarily be fine, but the auto-reset function means that the arduino resets whenever I send it data, and then it forgets the data!

I emailed Paul at Modern Device company to ask if there was an easy way to remove the auto rest function. Luckily there is! He said that the capacitor closest to the reset button is the one responsible. To remove auto reset you can remove the cap, cut the trace above or below the cap, or even remove the dtr line from the ftdi cable!

Here is a shot showing the assembled board. The cap is the blue guy poking out from behind the reset button.

Here is a pic of the board that paul sent me. I added the overlay showing where the cap is.

This is the cap that allows auto reset
This is the cap that allows auto reset

I think the best thing to do (as Paul suggested) is to add a female header to the spot where the cap normally lies. That way to re-enable auto reset all you have to do is to stick a cap in the header. Simple!

5 replies on “Removing the auto reset in Bare Bones Board Arduino”

  1. The easiest way to disable the auto reset on the Arduino Duemilanove is to connect a 110 ohm resistor to the +5v and reset header

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