Q: What are the best practices for low-power IoT device design to achieve multi-year battery life?
Answer
Achieving multi-year battery life requires aggressive power management: (1) Choose the right sleep mode: Hibernate (<1 uA) > Stop (1-5 uA) > Sleep (100-200 uA). (2) Use an ultra-low-power MCU (STM32L0 STM32L4 Nordic nRF52) as the primary controller. (3) Wake only on external interrupt (button PIR motion sensor) or scheduled interval using RTC. (4) Use duty cycling: wake for 100 ms transmit 10 mA and sleep for 10 min averaging <1 uA. (5) Disable all unused peripherals at the start of sleep. (6) Use buck converter (not LDO) for high-efficiency power conversion. (7) For LoRaWAN Class A: transmit and receive windows are time-aligned - sleep between. (8) Use events instead of polling: edge-triggered interrupts. (9) Compress data (COAP protobuf) to minimize transmit time. (10) Measure with a bench power supply with current integration - calculate mAh consumed.
Filed under: FAQ