Highlights
- Wired and programmed GSE control and sensing hardware: 12 V solenoid valves, relay modules, servos, pressure sensors, and XBee radios.
- Built the solenoid control channel: Arduino GPIO → relay module → 12 V battery → solenoid valve, wired through the relay's normally-open contact so valves stay de-energized unless commanded.
- Implemented XBee wireless serial communication with the Arduino for remote valve commands and real-time pressure telemetry.
- Produced the wiring diagram for the Arduino, XBee, relay, and solenoid interconnect.
- Bench-tested the system for sensor accuracy, wireless link stability, and end-to-end valve response.
Overview
NYU Rogue Aerospace is a student rocketry team operating through NYU's Vertically Integrated Projects (VIP) program. As a member of the electrical team, I work on the ground support equipment (GSE), the system that opens and closes valves and reports pressure remotely so that operators stay at a safe distance from pressurized hardware during testing.
My responsibilities cover the wiring and firmware for the GSE's solenoid valves, relays, servos, pressure sensors, and XBee radios.
System components
| Controller | Arduino Uno |
|---|---|
| Wireless link | XBee radios on 5 V adapter boards, serial interface to the Arduino |
| Valve switching | 1-channel 5 V relay modules |
| Valves | 12 V DC solenoid valves |
| Actuators | Servos for servo-actuated valves |
| Sensing | Pressure sensors read by the Arduino |
| Load power | 12 V battery |
| Station | Raspberry Pi with touchscreen display |
Solenoid control channel
Each solenoid valve is switched through a relay module. The Arduino supplies the module's 5 V logic power and drives its IN pin from a GPIO (D4). The module's onboard transistor stage energizes the relay coil, which connects the 12 V battery to the solenoid through the COM and NO contacts.
Wiring through the normally-open (NO) contact means the solenoid is energized only while the Arduino actively commands it. If the controller resets or loses power, the relay opens and the valve returns to its de-energized state. The 12 V load circuit is isolated from the 5 V logic by the relay.
Wireless command and telemetry
The XBee radio connects to the Arduino as a serial device on D10 and D11, powered from the Arduino's 5 V and ground. Commands received over the wireless link are parsed by the Arduino firmware and translated into relay outputs, and pressure-sensor readings are transmitted back to the ground station in real time.
Design process
I started by sketching the interconnect by hand to settle pin assignments and power routing between the Arduino, XBee, relay, battery, and solenoid, then built and tested the circuit on the bench. The diagram in Fig 2 is the formalized version of that sketch.
Integration and validation
I build, wire, and bench-test the GSE against three criteria:
- Sensor accuracy: pressure readings verified against a known reference.
- Wireless link stability: XBee link reliability under continuous transmission.
- End-to-end valve response: correct solenoid actuation in response to commands from the station.
Skills applied
- Relay-based switching of 12 V inductive loads from 5 V microcontroller logic.
- Fail-safe wiring practice using normally-open contacts.
- Embedded C/C++ firmware for serial communication, sensor acquisition, and actuator control.
- XBee configuration for wireless command and telemetry.
- Wiring diagrams, hardware integration, and structured bench testing in a safety-critical environment.