Inexpensive Oscilloscope Benefits from Inexpensive Enhancements
Tackling budget-friendly oscilloscopes for DIY enthusiasts and school labs? They might be affordable, but they often lack precision and can be noisy. Fear not, though! Here's an innovative approach to deck out your inexpensive device with a few enhancements. Follow along as we modify the DSO138-mini, and soon you'll see how even the cheapest gear can bring forth some high-quality outcomes.
Let's dive into [Tommy]'s project, which amps up the performance of the DSO138-mini—a 100kHz bandwidth, 10-bit oscilloscope. His primary focus is on implementing an anti-aliasing filter on the input, which is essentially a low-pass filter that nixes high-frequency components that could potentially disrupt readings due to the device's lower resolution. After filtering the input, digital post-processing comes to play, removing noise caused by quirks in the power supply and serving as a second low-pass filter.
Want to see the impact of these twin strategies? Just wait for Part 2, where [Tommy] demonstrates impressive results from the anti-aliasing filter and digital post-processing! And get this—the only additional expense is a $1 ceramic capacitor. Talk about budget-friendly! Plus, [Tommy] is just a high school junior, showing that big things can indeed come from small packages!
Got an even cheaper oscilloscope on hand? Apparently, you can apply these tactics toEsp32-based alternatives as well!
Now, let's break down the magic behind these modifications:
1. Signal Acquisition and Anti-Aliasing
- Design an Low-Pass Filter: Aim to prevent aliasing by attenuating frequencies above half the sampling rate (Nyquist frequency) with an RC filter or an active low-pass filter.
- Location: Always filter the signal before it reaches the ESP32's ADC to avoid aliasing.
2. Digital Post-Processing on the ESP32
- Reduce Noise with Digital Filters: Implement moving averages orIIR filters to smoothen out the waveform and eliminate broadband noise.
3. Software Flow
- Capture Analog Signal: Once the signal is filtered, read it with the ESP32 ADC.
- Apply Digital Filter: Process the ADC readings using a moving average orIIR filter.
- Visualization: Finally, send the processed data to a PC or display module for visualization.
Give this approach a shot, and you'll see how an inexpensive ESP32-based oscilloscope can churn out cleaner, more dependable measurements for lower-frequency signals. Although it won't quite match commercial oscilloscopes, it's perfect for educational and DIY purposes! Enjoy enhancing your budget-friendly gear with this upgrade.
This DIY project, focusing on a 100kHz bandwidth, 10-bit oscilloscope (DSO138-mini), demonstrates an innovative approach to improve the device's performance. An anti-aliasing filter is designed to prevent aliasing and nix high-frequency components, while digital post-processing eliminates noise caused by quirks in the power supply, acting as a second low-pass filter. This tactic can be applied to even cheaper oscilloscopes like Esp32-based alternatives, making education-and-self-development and learning more accessible with technology.
