The CrowPanel HMI device, based on the ESP32-P4 microcontroller, consumes approximately 600 mA at 60% screen brightness. This results in a battery life of less than 2 hours when using a 1000 mAh battery.
To improve energy efficiency, the author tested various power-saving modes. By disabling peripherals, turning off the backlight, and utilizing Light-sleep, the power consumption was reduced from 335.9 mA to 96.7 mA, a 71.2% decrease.
The test setup used a Nordic Power Profiler Kit II (PPK2) at a voltage of 4.0 V. The system includes a 7-inch IPS LCD, a GT911 touch controller, an ESP32-C6 coprocessor for wireless connectivity, and external PSRAM.
The ESP32-P4 features two high-performance RISC-V cores and a low-power coprocessor. The study utilized ESP-IDF 6.1.0, enabling features like PSRAM Half-sleep and flash memory Deep Power-Down to minimize power draw during idle periods.
The display driver's use of MIPI DSI and power management locks initially prevented automatic sleep. The author successfully implemented a wake-up mechanism triggered by the GT911 touch controller in Green mode to allow the system to enter Light-sleep between user interactions.
