For actuator / sensor IoT nodes, which send relatively small amounts of data at long intervals, the time "between the bursts" is of crucial importance. During these phases, consuming as little power as possible is the ultimate key to long battery life.
We examined the power management of Espressif’s ESP32 SoC with its ultra-low-power coprocessor ULP and present the results in this article.
The ESP32-Wrover-Kit2 provides a suitable platform for measuring the ESP32 SoC power consumption. On this development board, the 3V3 supply rail of the module is connected via an “0603”-footprint 0-ohm resistor, which is easily removed.
This allows us to measure the power consumption of the entire module, including FLASH and PSRAM. When the SoC is in deep sleep mode, both memories are disconnected from power supply and will only draw a very small amount of standby current.