user23991: I usually use Platformio as IDE for my Arduino projects. I like it as an editor, but I don't like its serial monitor feature. So I often open the Arduino IDE in background to use its serial monitor, but this has some drawbacks (including a significant increase in my computer's CPU usage and battery consumption).
Is there an Arduino-compatible serial monitor application that just works as a serial monitor (and not also as an IDE)? I'm most interested in a MacOS application, but if you know a Windows one please tell me as well.

user42384: There's a list of serial port sniffers here, if you want to view raw data
 softwarerecs.stackexchange serial-port-logging
And a list here of programs which plot graphs from serial data:
softwarerecs.stackexchange serial-data-plotting-programs 

user4628: I use CoolTerm, which is available for Mac, Windows and Linux. It is a great serial app, and you can have several windows open at the same, for each serial pipe you may be using (Bluetooth, Arduino Serial, etc).

user55364: Consider building your own monitor in Python. This gives you flexibility since Python is cross platform and you can tailor the monitor to your needs.

Install Python.
Install pySerial (pip install pyserial).
Write a Python script to read and/or write to the Arduino across the serial port. There are some great examples out there such as this example and other Stack Overflow answers.


user79789: On macOS, you can use the built-in screen command, e.g.:
screen /dev/cu.usbmodem14201 9600

To exit, control-A followed by control-\

23991: <p>I usually use <a href="http://platformio.org" rel="nofollow noreferrer">Platformio</a> as IDE for my Arduino projects. I like it as an editor, but I don't like its serial monitor feature. So I often open the Arduino IDE in background to use its serial monitor, but this has some drawbacks (including a significant increase in my computer's CPU usage and battery consumption).</p>

<p>Is there an Arduino-compatible serial monitor application that just works as a serial monitor (and not also as an IDE)? I'm most interested in a MacOS application, but if you know a Windows one please tell me as well.</p>
 42384: <p>There's a list of serial port sniffers here, if you want to view raw data</p>

<p><a href="https://softwarerecs.stackexchange.com/questions/7636/serial-port-logging/7639#7639"> softwarerecs.stackexchange serial-port-logging</a></p>

<p>And a list here of programs which plot graphs from serial data:</p>

<p><a href="https://arduino.stackexchange.com/questions/1180/serial-data-plotting-programs">softwarerecs.stackexchange serial-data-plotting-programs </a></p>
 4628: <p>I use <a href="http://freeware.the-meiers.org/" rel="nofollow noreferrer">CoolTerm</a>, which is available for Mac, Windows and Linux. It is a great serial app, and you can have several windows open at the same, for each serial pipe you may be using (Bluetooth, Arduino Serial, etc).</p>
 55364: <p>Consider building your own monitor in Python. This gives you flexibility since Python is cross platform and you can tailor the monitor to your needs.</p>

<ol>
<li>Install <a href="https://www.python.org" rel="nofollow noreferrer">Python</a>.</li>
<li>Install <a href="https://pythonhosted.org/pyserial/" rel="nofollow noreferrer">pySerial</a> (<code>pip install pyserial</code>).</li>
<li>Write a Python script to read and/or write to the Arduino across the serial port. There are some great examples out there such as <a href="https://www.thepoorengineer.com/en/arduino-python-plot/" rel="nofollow noreferrer">this example</a> and other <a href="https://stackoverflow.com/questions/24074914/python-to-arduino-serial-read-write">Stack Overflow answers.</a></li>
</ol>
 79789: <p>On macOS, you can use the built-in <code>screen</code> command, e.g.:</p>
<pre><code>screen /dev/cu.usbmodem14201 9600
</code></pre>
<p>To exit, <kbd>control</kbd>-<kbd>A</kbd> followed by <kbd>control</kbd>-<kbd>\</kbd></p>
