The Teensy 4.1 was the perfect fit for Arwing because it’s processing power, large flash memory, and eight UART pins—exactly what I needed for a project involving so many peripherals. The onboard SD card slot was a bonus since Arwing is currently all about gathering vehicle data during short missions to prep for a longer one.

My custom breakout board for the Teensy 4.1 has four UART interfaces, two I2C connections, a generic analog sensing pin, and a receiver for my custom power supply board. Large capacitors at the rudder servos prevent power dips, and magnetic isolators keep the brushless ESC outputs separate from the control circuitry.

Before I send Seafox out into the ocean blue, I need a lot of testing and data on its operation. The FS-IA6B allows me to take manual control at short ranges to test things like power consumption, speed, maneuverability, and stability. It’s complimenting controller has a twin-stick interface and a switch for easy toggling between manual and autopilot modes.

G-Diff’s uses have expanded beyond Arwing, and I actually keep one on my desk at all times for other projects’ power needs. It features dual buck converters, allowing it to efficiently supply up to 2 amps at 3.3v and 5v simultaneously. It also serves as a voltage and current monitor, outputting the readings as 3.3v analog signals.

For simple satellite text communication, the RockBLOCK was an obvious choice. It relays data from the Iridium satellite network, into one of the Teensy’s UART ports. Arwing’s custom algorithm works with the RockBLOCK to parse data, confirm transmissions, and check the module’s status.

Prior to this stage of development, there was no need to purchase an expensive SatComm module for testing. I simply needed a short-range text-to-UART relay. Bluetooth is my way of simulating the limitations of text-based satellite control, because the HM-10 uses the same data interface protocol as the RockBLOCK.

Although previous iterations used humbler GPS modules, I happily inherited this beauty last year. It automatically parses and outputs NMEA data over UART, including one crucial value: C.O.G., aka “Course Over Ground.” This will allow Seafox to navigate the seas based on its direction of travel, without worrying about exact cardinal alignment.

Considering that Seafox will eventually be a water-tight ocean-fairing vessel, temperature dissipation will be a challenge. Arwing currently includes two MCP9808s—one for monitoring the drive system, the other for ambient cabin temperature. The sensors communicate with Arwing using I2C, which allows for easy “stacking” on one pin.

The BNO-055 is a "late-game" module that’s not essential for Arwing’s operation but will significantly enhance its performance. Right now, rudder adjustments are based on preset intervals, but with the BNO-055, I’ll use data for more precise control, like turning based on degrees. Its onboard accelerometer, gyroscope, and magnetometer will also improve navigation and monitor ocean turbulence, or sea state.

Arwing is programmed and wired to control two brushless motors via PWM signals. The selection of ESCs is vast, thanks to the hobbiest community, and I frequently swap them out based on testing needs. This current selection was chosen for its bidirectionality. Since I’m frequently performing tests in narrow spaces, reversing the drive tends to come in handy.

The humblest component on Arwing, but not the least important. Afterall, what kind of monster would deprive the user of hearing custom “beep and boop” feedback signals? Not this kind.

A 20kg digital servo is used for rudder control. Its power is overkill for its current job, but I wanted something robust that could be applied to some experimental steering methods, like weight-shifting for banked turns.