Reducing MCU power consumption in practice

   The sleep mode of the microcontroller is mainly controlled by the PCON register, and its register is as shown below:

POF: Power-on reset flag. When the microcontroller is powered on for the first time, this flag is 1 and can be cleared by software.

PD: When it is set to 1, the microcontroller enters power-down mode and can be awakened by an external interrupt low level or falling edge triggered interrupt. When  entering down mode, the external clock, CPU, timer, and serial port all stop working, and only the external interrupt continues to work.

   In order to reduce the power consumption of the microcontroller and make it more energy-efficient, a sleep mode can be added to it. When no button is pressed within 3 minutes, the microcontroller enters sleep mode. Here, a parameter can be used for counting, that is, each time the remote control is pressed, the parameter is increased by 1. When no change is detected in this parameter within three minutes, it can automatically enter the Pown Down mode.

   The transmission mode of infrared remote control is as follows:

   By default, when IR1838 does not receive a signal, the output is high level. When a signal is received, the received signal will be inverted and output. Therefore, when a key code is received, it will first output a low level of 9ms, that is, a falling edge can trigger an external interrupt to wake up the microcontroller and start working. In this way, the power consumption of the microcontroller can be reduced.