Lets compare viability of which one to fork:

https://github.com/ardyesp/DLO-138 or https://github.com/siliconvalley4066/DLO-138-SPI

Introduction to Extending the DSO138 Oscilloscope DIY Kit

The DSO138 DIY oscilloscope is a popular, affordable kit for electronics beginners. This project aims to enhance it into a portable mobile oscilloscope while keeping it newbie-friendly, cheap, and modular for future upgrades. By adding simple extensions, we can maintain the spirit of the original kit while improving its functionality.

Main Goal for This Project:

- Add a second analog channel as an addon.
- Integrate a battery holder for portable, battery-powered operation.

Requirements:

Ensure compatibility with DLO138 firmware:

    - Two analog channels for more versatile signal analysis.
    - Two digital logic channels using the SWDIO and SWCLK pins (PA13 and PA14) on board.
    - Serial port interface for captured waveform data transfer.
    - Selectable trigger source from Analog Channel 1 or Digital Channel.
    - Rotary encoder option to replace +, -, and SEL switches.
    - 2K sample depth to enhance signal resolution.

Project Goals:

- Maintain affordability with low-cost components.
- Newbie-friendly design for easy implementation.
- Portability through battery-powered operation.
- Modular and future-proof for easy upgrades.
- Preserve the learning aspect of the original kit.

Wild Ideas with Great taste of Feature Creep Potential:

Here are some ideas that could significantly enhance the oscilloscope's functionality. Input is welcome on which of these would be easy and simple to implement with the right code:

- Improved Display Options: Larger or external display support (hard)
- Signal Storage: Add SD card slot for waveform saving. (hard)
- USB/PC Connectivity: Enable USB data transfer for real-time monitoring on a PC. (done? partially?)
- Wi-Fi/BT Connectivity: Integrate a nRF24L01 module for remote control and data transfer. (medium/hard) -> (Serial Data Bridge)
- Function Generator: Add XR2206 1Hz-1MHz function signal generator (Sine/Triangle/Square output) with adjustable frequency and amplitude. (Easy)
- Adjustable Power Source: Add a 5A 75W adjustable step-down converter module for powering external circuits during testing. (Easy)

Feedback on which of these ideas are cost-effective and easy to implement is encouraged. Some could be nearly free to add with the right software and slight hardware tweaks!

First step: ToDo

DSO138 3D model: Create a KiCAD-compatible 3D model of the DSO138 for easy matching and designing for footprint.