Let’s look at an event-sensing emergency-response system operating on a street light. Cold winter temperatures could cause the output power of a device to vary or the receiver sensitivity to degrade, resulting in a loss of communication. While less of a concern for a consumer device—which is rarely used in such extreme conditions—it would be unacceptable for an emergency-response system. At best, the cost is reputational damage to the end product, ending up in a service call to replace the faulty device. System designers must ensure that the components selected for the sensing and communication system are robust over changing environmental conditions.
Corrupted Memory Can Lead to Unexpected Outcomes Reliability is also a concern for the communications microcontroller. Although extremely reliable, both flash and non-volatile memory can occasionally become corrupted. This may occur as a result of unintended effects caused by the operating environment, or intentionally through malicious hardware hacking.
Regardless of the mechanism, it is imperative that microcontrollers are equipped with the necessary integrity features to identify when a device has been corrupted. Once identified, the microcontroller can either correct the error or shut the device down, ensuring that the security of the wider system is not breached.
Designing for Reliability
Analog Devices’ ADF7030-1 radio transceiver and ADuCM3029 Cortex-M3 microcontroller both help overcome the aforementioned challenges. They target performance levels and functionality features that lead to more robust communication links.
In many cases, the ADF7030-1 will be able to receive radio signals that are 3 dB lower than other similar radios. And with blocking numbers in excess of 100 dB, the ADF7030-1 can achieve a level of interference resilience comparable to military and aerospace equipment—without the need for additional costly external components. This ultimately lowers overall cost while ensuring communication is maintained in the noisiest RF environments.
Through generations of collaboration with leading industrial manufacturers, Analog Devices has developed methods for coping with real-life environmental effects on radio transceivers. As an example, the output power transmitted by a device using the ADF7030-1 varies by less than 0.2 dB over the full operating temperature range. Competing radios, on the other hand, often vary by up to 2 dB.
The ADuCM3029 is designed with flash and error-correction-code (ECC) parity checks to ensure errors caused by memory corruption are identified and corrected where possible. The microcontroller also comes with battery-monitoring capability in sleep mode. This ensures that unexpected drops in voltage are detected, and that the processor is in turn alerted to a possible malicious threat or power-supply malfunction. The end device can then take appropriate action, either by alerting an administrator or entering a safe mode to ensure the wider system is not compromised.
Technologies developed by Analog Devices inhabit every stage of the IoT signal chain, from sensing and measuring to interpreting and connecting the data. Ensuring the quality and integrity of the information created through this chain is a core design principle, and a fundamental requirement to fulfill the true potential of the IoT.
