IoT Hardware Devices and Processors ISE Practice Questions (Page 4)

Questions 16–20

1. 16expert · hard

   A team is developing a battery-powered asset tracker that must transmit its location every 5 minutes. The device uses a Cortex-M0+ microcontroller and a cellular modem. The average current draw in active mode is 50 mA for 2 seconds per transmission, and in sleep mode it is 10 µA. The battery has a capacity of 1000 mAh. Which strategy most effectively extends battery life?

   • AUse a higher clock speed to reduce the transmission time to 1 second.
   • BIncrease the transmission interval to every 10 minutes.
   • CReplace the Cortex-M0+ with a Cortex-A7 to process data faster.
   • DKeep the device in sleep mode only between transmissions, but leave the cellular modem powered on.
   Reveal Solution Discussion Select an answer first
2. 17foundation · easy

   Which processor architecture is most commonly associated with low-power, microcontroller-based IoT devices such as smart sensors and wearables?

   • AARM Cortex-A
   • BARM Cortex-M
   • CRISC-V
   • Dx86
   Reveal Solution Discussion Select an answer first
4. 18application · medium

   A company is designing a battery-powered environmental sensor that must run for two years on a single coin-cell battery. The device wakes every 15 minutes, reads temperature and humidity, and transmits a short packet over a low-power radio. The team is choosing between an ARM Cortex-M0+ microcontroller and an ARM Cortex-A7 microprocessor. Which factor is the primary reason to choose the Cortex-M0+?

   • AIt integrates flash and SRAM on-chip, reducing the need for external memory and lowering power consumption.
   • BIt has a memory management unit (MMU) required for virtual memory and process isolation.
   • CIt supports a full Linux distribution, simplifying application development.
   • DIt provides higher clock speeds, enabling faster processing of complex sensor algorithms.
   Reveal Solution Discussion Select an answer first
5. 19expert · hard

   A company is developing a solar-powered environmental sensor that must operate through several days of cloudy weather. The device uses an ARM Cortex-M4 microcontroller and a LoRa radio. The power budget is extremely tight. Which power management strategy is most effective?

   • AUse a duty-cycling approach with the microcontroller in deep sleep and the radio powered off between transmissions
   • BRun the microcontroller at maximum clock speed to finish tasks quickly and then enter sleep
   • CKeep the radio always on to ensure reliable communication
   • DUse a real-time clock to wake the device every second to check for commands
   Reveal Solution Discussion Select an answer first
6. 20application · medium

   A design team is building a wearable health monitor that must read data from three sensors: a temperature sensor, an accelerometer, and a heart-rate sensor. The microcontroller has limited GPIO pins. The sensors support both I2C and SPI interfaces. Which interface choice is most appropriate to minimize pin usage?

   • AUse GPIO with analog reading for all sensors.
   • BUse SPI for all three sensors, each with a dedicated chip-select line.
   • CUse I2C for all three sensors, connecting them on a shared bus with unique addresses.
   • DUse a separate UART for each sensor.
   Reveal Solution Discussion Select an answer first