#Esp32 enter deepsleep code#

There's only 8KB of static RAM so you can't store huge amounts of data there. For instance: RTC_DATA_ATTR unsigned wakeups You can declare a variable to live in the RTC RAM using RTC_DATA_ATTR. Its contents will be lost or cleared when the ESP32 loses power or is flashed. This RAM is built into the ESP32 and is maintained during deep sleep. You can also store data in the static RAM that's part of the real-time-clock (RTC). Writing to flash is slow and costs a lot of power, so this isn't great if you're running off a battery.

Obviously you can store data in flash memory using EEPROM or SPIFFS. There are a couple of ways to preserve state across sleep cycles.

Your setup() function will run again and will need to do any initialization again. So when it restarts out of deep sleep it's as if it just powered up. It costs power to maintain the contents of its memory and the CPU state, and the point of deep sleep is to save as much power as possible, so it stops powering these things. The contents of memory and the current state of the processor are lost. When the ESP32 enters deep sleep, it turns off the processor that's running your code. Serial.println(F('Failed to read from DHT sensor!')) īool ok = network.write(header, &pack0, sizeof(pack0)) If (isnan(pack0.humidity) || isnan(pack0.temperature)) Pack0.soil = map(analogRead(SOILPIN), 0, 4096, 100, 0) //convert to percentage Pack0.temperature = dht.readTemperature()

#Esp32 enter deepsleep code#

put your main code here, to run repeatedly: My code is attached below struct package0 So is all my void setup() code wiped out? Or just my pack0.temp, humid, soil is wiped out? Can I use deep sleep for my project?Įverything stored in that memory is wiped out and cannot be accessed. My next step is to put my slave in sleep mode (maybe deep sleep). Instead, this is run on the RTC so you'll have very little power consumption when you enter deep sleep and have one of the touch pins configured as wakeup source.I'm doing wireless sensor node using esp32 (slave) and rf24l01 module. Small side note: using the touch sensor as a wakeup source does not require the ULP. This tells the ESP32 to keep the touch sensor on when going to sleep. Here we want to make an exception for the touch sensor, and that's what we do with esp_sleep_enable_touchpad_wakeup(). Normally, when you enter deep sleep, the ESP32 powers down as many peripherals as it can to save power. TouchAttachInterrupt (T0, callback, TOUCH_THRESHOLD ) Setup interrupt on Touch Pad 0 (GPIO4) Translated into Arduino code, you'll get: # include

Enable the touch interrupt (so the ESP32 knows that it has to keep that powered on).

Configure a threshold value (once this value is crossed, the ESP32 will wakeup).

Now to allow the touch sensor to wake the ESP32 up, we have to do three things: However, you want to wake up when someone touches your device, so you can turn on the display and show something useful. To save power, you turn the display off and put the ESP32 into deep sleep. One way you can do that is with the touch sensors.Īn example could be that you have a battery-powered device with a display. At some point, an external interrupt is needed to wake it up. Deep sleep is great to save power, but you can't let the ESP32 sleep forever.