Soundcard Oscilloscope

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Audio setup THAT with external (USB) souncard connected to a computer (not depicted)

You can use the Soundcard of your computer or mobile device as an analog input/output interface to The Analog Thing. This page explains about details and gives recommendations about suitable hardware and software. Using the soundcard has the advantage of being very cheap (suitable soundcards in the range of 20€) compared to a real Oscilloscope (starting at 150€). The drawback are noticable skews and deviations in the data aquisition (for details see below)

An alternative to the missing inbuild audio input is a USB device. There are not many line-in stereo devices and most are only mono to use with microphones. A well tested device was the Behringer UFO202 with line-in and line out (each stereo) which is connected to USB, don't need any drivers and suitable for Windows, Mac and Linux in the price range of approx. 20 €. If your computer has already a microphone (mono) input you may buy a second cheap mono "microphone in" USB device for approx. 10 €. Be sure, that there is also an audio input and not just an audio output.

The Analog Thing audio connectors

The Analog Thing is already prepared to work with the above listed classic audio in devices as the used frequencies in an analog computation or simulation is mostly in the range of 20 Hz ... 20 kHz. There are 4 chinch connectors named with X, Y, Z, U which can be used either as signal output or signal input as well. The voltage range of +/- 10V of the reference voltage (representing the analog values 1.0 ... -1.0) is reduced by factor 10 to +/- 1V (representing 0.1 ... -0.1). This is a safe voltage for audio input devices (line in).

To feed signals into a soundcard you need to connect for example X and Y chinch connector to the line in jack of the computer or external sound device. Additional you must choose which signal in your analog circuit should be displayed by connecting any output of a computing element (integrator, summer, multiplier or comparator) to the OUT field on the front panel with a patch cable. If you want to input a signal to your analog circuit you do the same on the patch panel but connect the used chinch connector to an audio output. Some of the software solutions can display incoming signals but also offer signal generators additionally.

Be aware, that the chinch connectors are connected with a passive resistor divider and have a output impedance of approx. 500 Ohm. This is suitable for the audio inputs as the typical input impedance is in the range of approx 5-10 kOhm. Anyway the shown values for voltages of the software oscilloscopes are more or less an approximation or maybe can be adjusted by a factor in the configuration. Even audio outputs can often drive such impedances without problems. If an input signal of +/- 1V should be transferred in the range of +/- 10V it is easy to use the 10x input of a summer or integrator and use whose output.

Beside the chinch connectors it is easily to adapt signals directly at the patch cables with oscilloscope probes or feed signals directly with a cable adapter (cut one end of a patch cable and solder it to any signal of a programmable barebone controller board like arduino or similar.

Audio setup THAT with USB device

An alternative to the missing inbuild audio input is a USB device. There are not many line-in stereo devices and most are only mono to use with microphones. A well tested device was the Behringer UFO202 with line-in and line out (each stereo) which is connected to USB, don't need any drivers and suitable for WIN, Mac and Linux in the price range of approx. 20 €. If your computer has already a microphone (mono) input you may buy a second cheap mono "microphone in" USB device for approx. 10 €. Be sure, that there is also an audio input and not just an audio output.

The Analog Thing audio connectors

The Analog Thing is already prepared to work with the above listed classic audio in devices as the used frequencies in an analog computation or simulation is mostly in the range of 20 Hz ... 20 kHz. There are 4 chinch connectors named with X, Y, Z, U which can be used either as signal output or signal input as well. The voltage range of +/- 10V of the reference voltage (representing the analog values 1.0 ... -1.0) is reduced by factor 10 to +/- 1V (representing 0.1 ... -0.1). This is a safe voltage for audio input devices (line in).

To feed signals into a soundcard you need to connect for example X and Y chinch connector to the line in jack of the computer or external sound device. Additional you must choose which signal in your analog circuit should be displayed by connecting any output of a computing element (integrator, summer, multiplier or comparator) to the OUT field on the front panel with a patch cable. If you want to input a signal to your analog circuit you do the same on the patch panel but connect the used chinch connector to an audio output. Some of the software solutions can display incoming signals but also offer signal generators additionally.

Be aware, that the chinch connectors are connected with a passive resistor divider and have a output impedance of approx. 500 Ohm. This is suitable for the audio inputs as the typical input impedance is in the range of approx 5-10 kOhm. Anyway the shown values for voltages of the software oscilloscopes are more or less an approximation or maybe can be adjusted by a factor in the configuration. Even audio outputs can often drive such impedances without problems. If an input signal of +/- 1V should be transferred in the range of +/- 10V it is easy to use the 10x input of a summer or integrator and use whose output.

Beside the chinch connectors it is easily to adapt signals directly at the patch cables with oscilloscope probes or feed signals directly with a cable adapter (cut one end of a patch cable and solder it to any signal of a programmable barebone controller board like arduino or similar.