Arduino Oscilloscope

Projects General Guidance
1

Hello,

I am interested in making Arduino oscilloscope, but to ask You is it possible for it to display modulated signal, that is made of sin + and sin - (negative voltage) at the frequency of 10kHz.

Thank you for your time

2

Yes, it's possible. There are at least two significant complications in signal acquisition.

  1. The Arduino ADC (assuming Uno) has an input range of 0-5 Volts, so if you have a signal with negative voltage the signal will have to go through a level converter to shift the center voltage and match the amplitude to be compatible. One example of such a circuit is here: Non-Inverting Op-Amp Level Shifter - Daycounter

  2. To capture a signal at 10 kHz, the ADC sampling rate will have to be at least double that frequency and processing and display will be easier if the frequency is much higher. The normal Arduino Uno "analogRead()" function's conversion time is such that the maximum sample rate is less than 10 kHz. There are ways to get higher sample rates as per the following links: Faster analogRead and https://www.gammon.com.au/adc

3

To capture a signal at 10 kHz, the ADC sampling rate will have to be at least double that frequency

But in order to display a decent looking waveform you need at least 10 to 20 samples per cycle.

Here is a video of one I made earlier:-

The display computer was a Raspberry Pi and it was all written up in the Mag Pi 71 July 2018, free PDF download. The Arduino samples at 58K samples per second and has trigger and cursor measurements.