ANALOG REFLECTIONS IN HEX

How I Turned My Backyard into a Satellite Listening Post

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When I first discovered the NyanSat project on a Discord channel during my Hack-a-Sat journey, it felt like a spark. I had already been captivated by satellite hacking and space technology, but the idea of building a low-cost, open-source ground station to listen to satellites was irresistible. Enter Antenny, a compact, DIY satellite communication platform developed by Red Balloon Security as part of their mission to democratize space access.

This post dives into my hands-on experience assembling, programming, and using an Antenny ground station to connect with satellites in Low Earth Orbit.

What Is Antenny?

Antenny is more than just a hardware kit—it’s an invitation to explore the cosmos. Designed as part of the broader NyanSat project, Antenny offers a modular and accessible way to track and communicate with satellites. The kit combines off-the-shelf components with a custom-designed PCB to deliver functionality typically reserved for high-cost professional systems.

Key features include: - IMU Orientation: An inertial measurement unit (IMU) keeps the antenna pointed in the right direction without expensive motors or controls. - Antenny-MK7 Board: A custom PCB integrating an ESP32 microcontroller and motor driver for seamless operation. - Gimbal System: Enables azimuth and elevation adjustments to track satellites dynamically. - Micropython Firmware: Open-source code powers the entire system, offering flexibility and customization.

With Antenny, you don’t just observe satellites—you actively interact with them.

The Build

The kit arrived with a mix of excitement and intimidation. A pan/tilt gimbal, the Antenny-MK7 board, an IMU, and various jumpers and components filled the box. Here’s how I turned those pieces into a functioning ground station:

Step 1: Setting Up the Hardware

  • Positioning the IMU: The IMU’s placement on the gimbal arm was critical for accurate orientation. I followed the recommended setup but made minor adjustments for stability.
  • Mounting the Antenny Board: Ensuring no pins touched metal was crucial. I used a non-conductive base and hot glue for extra security.
  • Connecting the Jumpers: The Antenny-MK7 includes optional jumpers for IMU power and Wi-Fi connectivity. Soldering these jumpers was straightforward, but attention to detail was essential to avoid errors.

Step 2: Wiring and Calibration

  • Wiring Communication Lines: The IMU and servo communication lines needed precise matching between the PCB and board headers. A quick check with the manual confirmed the connections.
  • Servo Calibration: The elevation and azimuth servos were wired to the PWM controller. I configured them using the api.platform_set_coordinates method to ensure smooth movement.

Step 3: Flashing the Firmware

  • I flashed Micropython onto the ESP32 using esptool. Following the documentation, I:
  • Erased the flash memory.
  • Uploaded the Micropython firmware.
  • Installed the Antenny software using MPFShell, a Python-based tool for ESP32 development.

Programming the Ground Station

The heart of the Antenny system is its Python API, which provides high-level methods for controlling the platform. Here’s what I did:

  1. Initialization: python api.antenny_init_components() This step initialized the gimbal, IMU, and servos based on my configuration.

  2. Calibration: python api.antenny_calibrate() Running this routine aligned the IMU with the servos, ensuring accurate movement.

  3. Testing Movement: python api.platform_set_coordinates(az=90, el=45) This command pointed the antenna to a specific azimuth and elevation, confirming everything worked as expected.

  4. Data Reception: Once calibrated, I used the API to point the antenna at NOAA weather satellites and began receiving real-time data.

What I Learned

This project was more than just assembling a kit. It was an exercise in patience, problem-solving, and discovery. Here are some key takeaways:

  • DIY Doesn’t Mean Simple: While the kit is beginner-friendly, understanding the hardware-software interaction took effort.
  • Open Source Is Powerful: The flexibility of Micropython and the transparency of the Antenny firmware made debugging and customization straightforward.
  • Community Is Key: The NyanSat Discord was invaluable. From troubleshooting wiring issues to brainstorming upgrades, the community provided guidance and inspiration.

Applications and Future Plans

Antenny opens up a world of possibilities:

  • Satellite Tracking: Listen to transmissions from weather, communication, and amateur satellites.

  • Collaborative Research: Join a network of Antenny users to triangulate signals and study satellite debris.

  • Upgrades: I’m already planning enhancements, like integrating a better IMU for improved orientation accuracy and automating satellite tracking.

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