ATS20+ Upgrade to ATS-Mini Clone

ATS20 to ATS-Mini Upgrade

This guide details the physical preparation and hardware modification required to transform your ATS-20+ Radio into a high-performance ESP32-S3 based receiver. By replacing the original Arduino Nano with the Arduino Nano ESP32, the unit effectively becomes an ATS-Mini clone, capable of high-speed SPI display driving and advanced DSP firmware.

The process of upgrading the ATS-20+ involves a transition from the 8-bit architecture of the original board to the significantly more powerful 32-bit ESP32-S3 platform. This hardware evolution enables advanced features such as high-resolution color displays and more sophisticated digital signal processing (DSP).

Overview of the Modification Process

To complete this transformation, several key areas must be addressed:

1. Hardware Preparation: The original microcontroller is removed to make room for the Arduino Nano ESP32. This requires careful desoldering techniques to maintain the integrity of the PCB traces and pads.

2. Logic Level Adjustment: Since the ESP32-S3 operates on 3.3V logic compared to the 5V logic of the original Arduino Nano, voltage isolation is a critical step to protect the new components.

3. Display Integration: Replacing the original screen with an ST7789 LCD provides a more detailed interface. This typically involves using a 3D-printed front panel to accommodate the new screen dimensions and the existing rotary encoder.

4. Pin Mapping: The upgrade utilizes a specific pinout configuration to ensure the ESP32-S3 can communicate with the SI4732/35 radio chip and the new display. Functions such as the encoder phases, I2C communication for the radio, and SPI for the display are mapped to the high-speed GPIOs of the ESP32.

5. Firmware Installation: The "ATS-Mini" firmware must be flashed onto the ESP32-S3. This software is designed to leverage the increased processing power for better filtering, faster scanning, and a more responsive user interface.

Final Assembly

Once the internal modifications are complete, the unit is reassembled into its original aluminum enclosure. Proper alignment of the USB-C port and the BNC antenna connector is necessary for a professional fit and finish.

By merging the rugged build quality of the ATS-20+ with the modern processing capabilities of the ESP32-S3, the resulting receiver offers a significantly enhanced user experience. This project represents a comprehensive way to extend the life and capabilities of existing radio hardware through modern engineering.

Use the information at https://esp32-si4732.github.io/ats-mini/flash.html to write the firmware to the Nano ESP32.

The project contains full instruction to help guide you through the upgrade process.