Linux notes: Configuring XP-Pen drivers on Linux

When you plug in your Xp-pen graphic tablet into your Linux machine (i am running xubuntu-18.04), you will notice that the XP-Pen that you are using will be detected in the ‘Mouse and Touchpad’ settings tab:

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But the pen may not work! Although the device is enabled, writing on the drawing tablet using the pen does not have any effect. If you stumble upon this problem then there is a fairly simple solution that will resolve this issue:
Solution:

The solution that worked was downloading the Linux Beta driver from the xp-pen’s official website ( https://www.xp-pen.com/download-55.html )

Screenshot_2019-12-21_15-01-07(i) Make a dedicated directory *:

mkdir /home/User/Linux

(ii) Unzip all the contents of the downloaded Linux Beta driver from xp-pen’s website into ‘/home/User/Linux/’ directory

Here’s what my Linux directory looked like :

Screenshot_2019-12-21_15-05-39

(iii) Make Pentable_driver.sh as executable

cd /home/User/Linux
chmod +x Pentablet_Driver.sh

(iv) Connect your device and run Pentablet_Driver.sh

(sudo) ./Pentablet_Driver.sh

Screenshot_2019-12-21_15-09-39

The above screen should pop up and your device should work ! Open gimp to test it out.

 

** I had to make a dedicated directory titled Linux and place it under the home directory for this to work. Else I constantly  run into issues loading the xp-pen’s library files. I tested on two Xubuntu machines and both had the same issue. But this may not been a necessary step for other distros.

Making sensors come alive using the drawdio circuit

Key Insight: We took the output of the drawdio circuit and connected it to the mic pin of the headphone jack like so :

This was our key breakthrough. Having interfaced the drawdio with the computer opened a plethora of possibilities for us to play around with.

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In this following videos, we have connected the pin -3 of the drawdio circuit (above) to the mic of the headphone jack and in the placeholder of R5, we insert different sensors such as the LDR(Light dependent Resistor). IR led, etc. This allows us to have an audible feedback from the sensors that are connected, making them ‘come alive’.

 

Do not connect a speaker directly to a headphone jack (Speaker Impedance)

During the early days of exploring the headphone jack, we did some crazy stuff all in the name of science. And although many of them resulted in ecstatic moments of awe that we cherished, sometimes things went a little out of hand. But we learned important things from this experience.

In one of our previous posts, we showed you how we nearly fried our headphone jack ( appropriately titled Don’t do this! ). And in this post we will show you how to keep your USB port safe while playing around with speakers.

Speaker Impedance

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It is important to note that the speaker offers resistance to the flow of electrons. And when dealing with DC, we call it resistance but when one is dealing with AC it goes by the name of impedance.

And by virtue of Ohm’s law , we get that:

Lower the impedance → more current → greater load → increased power

Raise the impedance → less current → smaller load → decreased power

And as a general rule of thumb, small speakers (like the ones on your headphone) offer really high resistance to the flow of current and larger ones offer little to no resistance at all.

This caused us an Arduino because we accidentally connected ~4 Ohm speaker to the Arduino. And due to its low impedance, it became power greedy and destroyed it while also temporarily shutting down the USB port. So, yet another thing that one must be careful about.

How to be careful ?

Now that you know about speaker impedance and what it can do, we strongly suggest that you read the following article  to enlighten yourself:

Understanding Speaker Impedance

 

 

 

 

Simple Mobile Phone Detector using headphone jack

Mobile phones send wireless signals to the nearby station in order to help you send your message or connect with another phone.

But the best part about this is that these signals can be captured whether or not you have a mobile phone or not.  And the even cooler part about this is that this can be accomplished with nothing more than just a simple headphone jack connected to your laptop/phone.

drawing

There is nothing at all you need to do besides sticking a headphone into your jack and placing a mobile phone nearby.  Then open Audacity and record it at the maximum sampling rate possible on your soundcard. That’s about it !
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Video Demo:

NOTE:

This works remarkably well with older phones (that still use the 2G spectrum), but unfortunately we are still unable to crack into smartphones (that use 3G or 4G spectrum. Argg.. ) using this technique.

But that being said, we are trying our best to crack in. Would highly appreciate any input on this whatsoever. Have a good one!

 

More interesting stuff:

Sound of the dialup modem