Deep Sleep Tutorial for ESP32 Using the RTC ULP Co-processor and Two Lines of Code | #IoTuesday
This is a handy video from educ8s.tv – if you’re looking to use the ESP32 for battery-powered projects you might want to watch this. Or if you just wanna dive right in you can download the code and read more here.
Welcome to this ESP32 Deep Sleep tutorial with the Arduino IDE! Today we are going to learn how to put the ESP32 chip into the Deep Sleep mode in order to conserve power and make our projects battery friendly. There is a lot to cover so let’s get started!
The ESP32 chip is a fantastic new chip with great features. It offers a lot of processing power, two 32 bit cores, a lot of memory, Bluetooth and WiFi in a small and easy to use chip. One of the most interesting things about the ESP32 chip is that it offers a low-power deep sleep mode which is very easy to use. Let’s see how to use it.
Inside the ESP32 chip, we can find the two processing cores, the RAM and ROM memory, the WiFi module, the Bluetooth Module, a hardware acceleration module for cryptographic applications, the RTC module, and a lot of peripherals. Inside the RTC module, we can find a PMU (Phasor measurement unit) a small and very low power 32-bit co-processor, and 8Kbs of RAM memory. This small amount of memory is very useful as you are going to find out in a moment. Also note, even the RTC memory of the ESP32 chip is 4 times larger than the memory of the Arduino Uno.
The WiFi modules, the Processing Cores, and the Bluetooth module require a lot of current to operate. So, if we want to conserve power we have to disable them when don’t use them. This is what we are going to do now. We are going to put the ESP32 to Deep – Sleep mode where it disables everything except the RTC module. There is a light sleep mode and the Deep – Sleep mode. In Deep Sleep mode the ESP32 offers the lowest power consumption. It just needs 0.01 mAs of current in Deep Sleep mode and that’s why we are going to try today.
