Advanced Networking & Control Capabilities in the Thermal Control Unit, FTP, gRPC
- April 3, 2026
- CAVU Aerospace UK
We continue to push the boundaries of embedded avionics systems with the latest upgrade to its TCU. Designed for high-reliability aerospace environments, this upgrade introduces advanced networking, telemetry, and control capabilities—enabling smarter, more connected, and more maintainable thermal management systems.
- FTP logging and file service to store telemetry and housekeeping logs on eMMC, with start/stop control and status reporting.
- gRPC unary server for remote command execution (ping, configuration, telemetry, control, logging commands) over TCP/IP.
- SNTP client to synchronize device RTC time from a network time server.
- RTC management for read/write timekeeping and timestamped logging.
- Heater and thermistor control pipeline for configuration, state control, and power/temperature readback.
- Housekeeping telemetry acquisition and converted engineering-value reporting.
- eMMC management features including filesystem operations and format command.
- RS232 and RS422 command compatibility path alongside network gRPC control.
- FreeRTOS-based multitask firmware architecture with lwIP networking and protocol services.
Integrated FTP Logging & File Services
The upgraded TCU now includes a fully embedded FTP logging and file service, allowing onboard storage and retrieval of system data via standard network protocols.
Key Capabilities:
- Storage of telemetry and housekeeping logs directly to onboard eMMC
- Remote start/stop control of logging sessions
- Real-time status monitoring
- Standard FTP access for file retrieval and maintenance
gRPC-Based Remote Command Interface
A major enhancement is the introduction of a gRPC unary server over TCP/IP, enabling modern, high-performance remote control of the TCU.
Supported Command Domains:
- Connectivity checks (e.g., ping)
- Configuration management
- Telemetry access
- Thermal control operations
- Logging control
Network Time Synchronization (SNTP Client)
Accurate timing is critical in aerospace systems. The TCU now integrates an SNTP client to synchronize its internal clock with a network time server.
Features:
- Automatic RTC synchronization
- Improved temporal alignment across subsystems
- Support for distributed system coordination
Real-Time Clock (RTC) Management
Complementing SNTP functionality, the TCU provides full RTC management capabilities.
Functions:
- Read/write access to system time
- Timestamping of all logged data
- Persistent timekeeping across reboots
Heater & Thermistor Control Pipeline
The upgraded system enhances thermal regulation through a robust heater and thermistor control pipeline.
Capabilities:
- Configurable control parameters
- Real-time state control
- Power monitoring and temperature readback
Housekeeping Telemetry Processing
The TCU now includes advanced housekeeping telemetry acquisition and conversion.
Features:
- Raw sensor data acquisition
- Conversion into engineering units
- Structured telemetry reporting
eMMC Storage & Filesystem Management
Robust onboard storage is supported through enhanced eMMC management features.
Capabilities:
- Filesystem operations (read/write/delete)
- Remote formatting command
- Storage health management
Multi-Interface Command Compatibility
To ensure backward compatibility and flexible integration, the TCU supports both legacy and modern interfaces.
Interfaces:
- Network-based control via gRPC
- Traditional RS232 and RS422 command paths
FreeRTOS-Based Multitasking Architecture
At the core of the upgrade is a robust firmware architecture built on FreeRTOS, combined with lwIP networking.
Architecture Highlights:
- Deterministic multitasking
- Efficient resource management
- Integrated TCP/IP stack with protocol services
This upgrade transforms the TCU into a fully network-enabled, intelligent thermal management system. By combining modern communication protocols like gRPC, robust onboard storage, precise timing synchronization, and flexible control interfaces, CAVU Aerospace UK has delivered a solution that meets the evolving demands of aerospace platforms.
These features aside, we have several versions of TCU for different number of heaters channel, control (PWM or Linear buck), COTS, Radiations tolerant which fairly can cover thermal management issues in space missions.
