UART or Universal Asynchronous Receiver-Transmitter, enables reliable serial communication between digital devices. First, it converts parallel data into serial form for transmission. Then, the receiving side reconstructs the data into parallel form again. Because of this, the simple interface is widely used in embedded navigation systems. Inertial navigation systems, or INS, rely on real-time sensor communication. Consequently, a UART provides a lightweight and efficient method to connect IMUs to processors.
Unlike more complex interfaces, UART does not require a dedicated clock line. Instead, data is transferred using configurable baud rates and standard framing formats. Each transmission includes start, data, parity, and stop bits. Therefore, this structure ensures error detection and synchronization across devices. In practice, INS modules generate large streams of accelerometer and gyroscope data.
UART Baud Rate and Output Rate
The baud rate defines how many symbols or bits per second UART transmits. A higher baud rate increases throughput, which is essential for fast IMU data transfer. However, higher speeds also make the signal more sensitive to noise and line quality. The output rate of the IMU determines how often the sensor generates navigation data. For instance, an IMU may output measurements at 200 Hz or higher. To transmit this data reliably, the UART baud rate must be chosen to accommodate the sensor’s data volume plus protocol overhead.
The cable length directly impacts UART performance. Longer cables increase capacitance and resistance, which can distort signals at high baud rates. As a result, shorter cables allow higher baud rates, while longer cables may require reduced baud rates to maintain data integrity. For example, a 115200 baud rate may work reliably over several meters, but rates above 1 Mbps usually demand very short, well-shielded cables.
Therefore, engineers must balance these three parameters. If an IMU has a high output rate, a sufficiently high baud rate is required, but the cable length must remain short to avoid data loss. Conversely, if longer cabling is unavoidable, reducing baud rate or using differential signaling interfaces, such as RS-422 or RS-485, ensures stable communication.
As a result, the UART channel delivers this information directly to the navigation computer. Latency is minimal, and the protocol requires very low overhead. Thus, engineers prefer UART for simple and robust system integration. Furthermore, the interface supports flexible wiring and minimal hardware resources. It is particularly effective in compact or power-constrained applications. In addition, in defense and aerospace INS, reliability and stability are critical requirements.
UART ensures continuous data flow without complicated communication stacks. Moreover, developers can optimize baud rates to match sensor data rates. For example, high-rate IMUs output several kilobytes per second. Therefore, the UART interface can handle this demand when configured correctly.
Meanwhile, flow control techniques prevent data loss under high-load conditions. Hardware or software buffers also manage asynchronous data bursts efficiently. In turn, the deterministic behavior of UART improves predictability in embedded systems. To enhance integrity, designers often combine UART with higher-level protocols. Consequently, error checking and packet framing add robustness to navigation data exchange. This approach ensures precise communication under challenging operational environments.
In conclusion, UART provides a proven solution for INS sensor integration.