Baud rate defines the number of signal changes transmitted per second in a communication channel. It measures communication speed in terms of symbols rather than raw bits. Many digital systems equate baud rate with bits per second, but that is only true when each symbol carries one bit.
Modern modulation schemes often encode multiple bits per symbol, so the bit rate may exceed the baud rate. In embedded systems and inertial sensors, baud rate usually refers to the speed of exchanging data bits over a serial line.
Data throughput requirements
A high-performance MEMS inertial measurement unit (IMU) may produce hundreds of samples per second. Each sample might include readings from three gyroscopes, three accelerometers, and possibly a magnetometer or barometer. Depending on the resolution (e.g., 16-bit or 32-bit integers), a single data frame can easily reach several dozen bytes.
For instance, consider an IMU outputting 100 samples per second, each sample containing 24 bytes of data. That equates to:
100 samples/s × 24 bytes/sample = 2,400 bytes/s
Since each byte is typically transmitted with a start and stop bit (10 bits total), the raw transmission rate becomes about 24,000 bits/s. In this case, a 38,400 baud rate would be sufficient.
However, higher sampling rates or additional data fields (e.g., temperature, status flags, timestamping) demand higher baud rates. Many professional IMUs therefore support 115,200 baud or even 921,600 baud to guarantee sufficient bandwidth.
Latency considerations
In inertial navigation, latency is just as important as throughput. Navigation algorithms—such as strapdown integration for attitude and position estimation—require fresh data at precise intervals. If the baud rate is too low, sensor readings may arrive late, degrading navigation accuracy.
By setting a higher baud rate, designers reduce communication delays, ensuring that each sensor update is delivered in near real time. This is particularly critical in aerospace, marine, and autonomous vehicle applications, where navigation errors can accumulate rapidly.
Reliability and noise immunity
Higher baud rates increase speed but also raise susceptibility to errors from electromagnetic interference, cable impedance, and grounding issues. In harsh environments, such as heavy machinery or military platforms, engineers often select conservative baud rates. This approach maximizes robustness and ensures stable communication under demanding operating conditions.
Some inertial systems offer configurable baud rates, allowing integrators to adapt communication speed depending on system architecture and environmental constraints.
Applications of Baud Rate
The baud rate is far more than just a number in a configuration menu—it is a key enabler of reliable communication between electronic devices (UART). In the realm of inertial sensors and navigation systems, it directly influences data throughput, latency, and robustness.
Selecting the right baud rate requires balancing system needs: too low, and data may bottleneck; too high, and transmission may suffer from errors. As inertial sensors become more sophisticated and applications demand higher precision, the ability to optimize baud rate settings remains an essential skill for engineers and system integrators.
In short, whether you are integrating a compact MEMS IMU in a drone or a tactical-grade INS in an aircraft, paying attention to baud rate ensures that your navigation data flows smoothly, accurately, and reliably—keeping your system on course.