2.3 Ambient Temperature Application with APM and Sleep mode

This application will use the APM for the sensor data readings and processing scheduling and Sleep mode for power optimization.

Important: It is recommended to add an NOP as the immediate instruction after the SLEEP instruction.

This scenario presents the lowest current consumption with an average of around 13.8 µA, which signifies a decrease of up to 90 times compared to the first scenario and up to 30 times compared to the second scenario due to the usage of the SLEEP instruction that puts the CPU in the lowest power consumption mode. The current in Sleep mode is around 1 µA, and the ADC readings are approximately 30 µA. The UART usage for printing data on the PC terminal includes a significant current input, around 400 µA.

Figure 2-4. Current Measurements Using APM and Sleep Mode

Figure 2-5. **Temperature Readings in Data Visualizer**

Expanding the formula for the average needed current, based on the third application example, the conclusion is that the current consumption will decrease if increasing the APM period. For example, the desired period can be up to one hour. Without considering the short pulses that represent only the ADC readings, every eighth period of the signal will stay ON approximately 0.24 seconds (240 ms) and in Sleep mode for the rest of the time, around 3600 seconds - so the average current will be the same as in Sleep mode, around 1.18 μA. The APM offers a flexible scheduling system for the analog peripherals, which various sensor applications can take full advantage of.