XIAO ESP32S3 Deep sleep current

The Wiki says that the deep sleep current of the XIAO ESP32C3 should be ‘about’ 43uA.

With the code below, which wakes up the XIAO, flashes an LED and goes back to sleep the deep sleep current is 115uA.

The line;


Makes no difference to the deep sleep current, so why is the deep sleep current so high ?

  Tested on Seeduino XIAO ESP32C3

  Program Operation - This program is for the Seeeduino XIAO ESP32C3. The program is woken up by the RTC
  timer after the configured number of seconds, flashes the LED for a while then goes back to sleep. 
  To use the sleep mode without the USB lead connected you need to comment out the #define DEBUG 
  line so that all the Serial operations are excluded from the program. 

  Sleep current using this mode of RTC wakeup was 115uA.

  Serial monitor baud rate is set at 115200.

#define uS_TO_S_FACTOR 1000000ULL                 //Conversion factor for micro seconds to seconds
#define TIME_TO_SLEEP  15                         //Time ESP32 will go to sleep (in seconds)
#define LED1 D6                                   //external LED on this pin 

//#define DEBUG                                   //enable this define to turn on Serial prints  

void loop()
  led_Flash(10, 500);                             //10 seconds slow LED flashes show wakeup from deep sleep

#ifdef DEBUG
  Serial.println("Setup ESP32 to sleep for every " + String(TIME_TO_SLEEP) + " Seconds");
  esp_sleep_enable_timer_wakeup(TIME_TO_SLEEP * uS_TO_S_FACTOR);
  //The following command is intended to turn off all RTC peripherals in deep sleep.


#ifdef DEBUG
  Serial.println("This will never be printed");

  led_Flash(100, 25);                               //LED will (should) never flash

void led_Flash(uint16_t flashes, uint16_t delaymS)
  uint16_t index;
  for (index = 1; index <= flashes; index++)
    digitalWrite(LED1, HIGH);
    digitalWrite(LED1, LOW);

void setup()
  pinMode(LED1, OUTPUT);
  led_Flash(2, 125);                                         //two quick LED flashes to indicate program start

#ifdef DEBUG
  Serial.println(F("7_Deep_Sleep_Timer_Wakeup Starting"));

I just tested your code on my XIAO ESP32C. Those are my power sources and the readings:

Powering the Xiao using a LiPo battery (charged to 3.95V at the moment of test) soldered to the bat+ and bat- on the back side of the board:
Led blinking (awake): 17 ~ 20mA | Deep sleep: ~ 41uA
Powering the Xiao using a 5V breadboard power supply connected to the 5V pin on XIAO:
Led blinking (awake): 18 ~ 20mA | Deep sleep: 172 ~ 178uA
Powering the XIAO using a 3.3V breadboard power supply connected to the 3.3V on XIAO:
Led blinking (awake): 17 ~ 19.5mA | Deep sleep: ~92uA

I am a newbie here, sorry I can’t help you but those readings may help you somehow.

It does.

It seems the circa 41uA deep sleep might only be available from the battery connection.


1 Like

I have a question,how is this low current level measured?

Sampling resistors and amplifiers used?

With a multimeter in series with the battery lead.