user34207: I'm trying to set up a system using an that delivers a specific number of digital pulses to a device using one of the digital pins. The number of pulses delivered is specified over a the Mega's USB serial connection using a Python script (or terminal for debugging).
When I close the serial connection to the Arduino, I get a short "blip" that looks like a digital high (see image below). This happens when I disconnect in PySerial using Serial.close() or when I simply close my Arduino IDE terminal window.
It does not occur when I press the reset button on the board
Any ideas on how to get rid of this?  Thanks!


user39872: When you connect and disconnect from the Arduino, the usb host chip resets the entire device. If you do not want this you can cut the RESET trace on the board.

some boards have a jumper here instead that can be removed.
more info here
https://playground.arduino.cc/Main/DisablingAutoResetOnSerialConnection

34207: <p>I'm trying to set up a system using an that delivers a specific number of digital pulses to a device using one of the digital pins. The number of pulses delivered is specified over a the Mega's USB serial connection using a Python script (or terminal for debugging).</p>
<p>When I close the serial connection to the Arduino, I get a short &quot;blip&quot; that looks like a digital high (see image below). This happens when I disconnect in PySerial using <code>Serial.close()</code> or when I simply close my Arduino IDE terminal window.</p>
<p>It does not occur when I press the reset button on the board</p>
<p>Any ideas on how to get rid of this?  Thanks!</p>
<p><a href="https://i.stack.imgur.com/mMOw8.png" rel="noreferrer"><img src="https://i.stack.imgur.com/mMOw8.png" alt="blip on disconnect" /></a></p>
 39872: <p>When you connect and disconnect from the Arduino, the usb host chip resets the entire device. If you do not want this you can cut the RESET trace on the board.
<a href="https://i.stack.imgur.com/t9Uoo.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/t9Uoo.jpg" alt="enter image description here"></a></p>

<p>some boards have a jumper here instead that can be removed.</p>

<p>more info here</p>

<p><a href="https://playground.arduino.cc/Main/DisablingAutoResetOnSerialConnection" rel="nofollow noreferrer">https://playground.arduino.cc/Main/DisablingAutoResetOnSerialConnection</a></p>
