High power consumption when using BLE nrf52840 sense

Products & Technology XIAO
#1

Hi,

I am using nrf52840 sense. Using non mbed board. With the code below and using a multimeter I am getting 7mA current draw. This seems too high. Is there a way to optimize?

#include <bluefruit.h>
#include <Adafruit_FlashTransport.h>
#include <nrf_sdm.h>
#include <nrf_power.h>

BLEService uploadService("4fafc201-1fb5-459e-8fcc-c5c9c331914b");
BLECharacteristic dataCharacteristic("aeab4b05-a5fd-4c89-89de-17f1509e2734");
BLECharacteristic batteryLevelChar("9f83442c-7da2-49ca-94e3-b06201a58508", BLERead | BLENotify);
BLECharacteristic batteryStateChar("2BED", BLERead | BLENotify);

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);

  Bluefruit.autoConnLed(false); 
  Bluefruit.configPrphBandwidth(BANDWIDTH_MAX);
  Bluefruit.setName("Test");
  Bluefruit.begin();
  Bluefruit.setName("Test");

  Bluefruit.setTxPower(4);
  // Bluefruit.Periph.setConnectCallback(connect_callback);
  // Bluefruit.Periph.setDisconnectCallback(disconnect_callback);


  Bluefruit.Periph.setConnInterval(24, 60);
  Bluefruit.configPrphBandwidth(BANDWIDTH_MAX);
  Bluefruit.configUuid128Count(15);

  uploadService.begin();
  dataCharacteristic.setProperties(CHR_PROPS_NOTIFY);
  dataCharacteristic.setFixedLen(247);
  dataCharacteristic.begin();
  batteryLevelChar.begin();
  batteryStateChar.begin();

  Bluefruit.Advertising.addService(uploadService);

  Bluefruit.Advertising.restartOnDisconnect(true);
  Bluefruit.Advertising.addName();
  Bluefruit.Advertising.setIntervalMS(100, 153); // in unit of 0.625 ms
  Bluefruit.Advertising.setFastTimeout(30);     // number of seconds in fast mode
  Bluefruit.Advertising.start(0);

  digitalWrite(LED_BUILTIN, LOW);   // turn the LED off by making the voltage LOW
}

// the loop function runs over and over again forever
void loop() {
}
#2

Adjust the transmission power (Bluefruit.setTxPower(4)) to the lowest setting that maintains reliable communication within your required range.

#3

Hi llala_lolo,
Post 13 in the link below may be helpful.
You can reduce current consumption by just using DCDC mode.

// Enable DC-DC converter
NRF_POWER->DCDCEN = 1;

‘System_ON_Sleep of XIAO BLE - #13 by msfujino’