How do you choose sensors for embedded systems?

1 Sensor types and specifications

Sensors can be classified into different types based on their function, output, and measurement. For example, some common sensor types are temperature, pressure, humidity, light, motion, sound, and gas sensors. Each sensor type has its own specifications that describe its performance and characteristics, such as range, resolution, sensitivity, accuracy, precision, response time, and noise. You should compare these specifications with your project requirements and choose the sensor type that matches your needs and budget.

2 Sensor interface and communication

Sensors need to communicate with the embedded system through an interface that defines how they send and receive data. The interface can be analog or digital, depending on the type of signal that the sensor produces. Analog sensors output a continuous voltage or current that varies with the measured quantity, while digital sensors output a discrete binary code that represents the measured quantity. You should choose the interface that is compatible with your embedded system and provides the desired level of resolution and speed. Some common interface standards are I2C, SPI, UART, and CAN for digital sensors, and ADC, DAC, and PWM for analog sensors.

3 Sensor calibration and compensation

Sensors are not perfect devices and they may have some errors or deviations from their ideal behavior. These errors can be caused by factors such as manufacturing defects, environmental conditions, aging, and interference. To ensure the accuracy and reliability of your sensor data, you need to calibrate and compensate your sensors regularly. Calibration is the process of adjusting the sensor output to match a known reference value, while compensation is the process of correcting the sensor output for the effects of external variables, such as temperature, humidity, or pressure. You should choose sensors that have built-in calibration and compensation features or provide methods and tools to perform them manually.

4 Sensor placement and orientation

Sensors need to be placed and oriented properly to ensure that they measure the intended quantity and avoid errors or interference from other sources. The placement and orientation of your sensors depend on the type of sensor, the physical layout of your embedded system, and the environmental conditions. You should choose sensors that have flexible mounting options and provide clear instructions and guidelines for optimal placement and orientation. You should also consider the impact of your sensor placement and orientation on the performance and safety of your embedded system and avoid potential hazards or conflicts.

5 Sensor testing and validation

Sensors need to be tested and validated before and after integrating them into your embedded system to ensure that they work as expected and meet your project specifications. Testing and validation are the processes of verifying and evaluating the sensor functionality, performance, and quality using various methods and tools. You should choose sensors that have standard testing and validation procedures and provide documentation and support for them. You should also perform your own testing and validation using realistic scenarios and conditions that simulate your embedded system operation and environment.

6 Sensor maintenance and troubleshooting

Sensors need to be maintained and troubleshooted regularly to ensure their longevity and reliability. Maintenance is the process of cleaning, inspecting, and repairing your sensors to prevent or fix any issues or damages. Troubleshooting is the process of identifying and solving any problems or errors that affect your sensor operation or data. You should choose sensors that have low maintenance requirements and provide easy and effective troubleshooting methods and tools. You should also follow the best practices and recommendations for sensor maintenance and troubleshooting provided by the sensor manufacturer or supplier.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?