XIAO BLE Sense - LSM6DS3 INT1 Single Tap Interrupt

Products & Technology XIAO
46

Hi there,
Yes, So I went back and found the one that works with 1.1.8 as well, it’s a single nudge/tap and could be adjusted to the same function as the original, but this one sleeps properly and shuts down the flash also. It stays asleep until you beat it up a little (low sensitivity)
You can blend these two together and get what you need.
HTH
GL :slight_smile: PJ :v:

// This is compiled with BSP 1.1.8 , sleeps AOK, and wakes up with a nudge via the Tap 
// interrupt as GPIO
// toasted and poached by PJG 4/29/24
//
#include <Adafruit_SPIFlash.h>
#include <LSM6DS3.h>
#include <nrf52840.h>
#include <Wire.h>

Adafruit_FlashTransport_QSPI flashTransport;
LSM6DS3 myIMU; // Default is I2C mode

void QSPIF_sleep(void)
{
  flashTransport.begin();
  flashTransport.runCommand(0xB9);
  flashTransport.end();
}

void setupWakeUpInterrupt()
{
  // Start with LSM6DS3 in disabled to save power
  myIMU.settings.gyroEnabled = 0;
  myIMU.settings.accelEnabled = 0;

  myIMU.begin();

  // Set up the accelerometer for Wake-up interrupt.
  // Per the application note, use a two step set up to avoid spurious interrupts
  // Set up values are from the application note, and then adjusted for minimum power

  myIMU.writeRegister(LSM6DS3_ACC_GYRO_WAKE_UP_DUR, 0x00); // No duration
  myIMU.writeRegister(LSM6DS3_ACC_GYRO_WAKE_UP_THS, 0x02); // Set wake-up threshold
  myIMU.writeRegister(LSM6DS3_ACC_GYRO_TAP_CFG1, 0x80);    // Enable interrupts and apply slope filter; latch mode disabled
  myIMU.writeRegister(LSM6DS3_ACC_GYRO_CTRL1_XL, 0x70);    // Turn on the accelerometer
                                                           // ODR_XL = 833 Hz, FS_XL = ±2 g
  delay(4);                                                // Delay time per application note
  myIMU.writeRegister(LSM6DS3_ACC_GYRO_CTRL1_XL, 0xB0);    // ODR_XL = 1.6 Hz
  myIMU.writeRegister(LSM6DS3_ACC_GYRO_CTRL6_G, 0x10);     // High-performance operating mode disabled for accelerometer
  myIMU.writeRegister(LSM6DS3_ACC_GYRO_MD1_CFG, 0x20);     // Wake-up interrupt driven to INT1 pin

  // Set up the sense mechanism to generate the DETECT signal to wake from system_off
  // No need to attach a handler, if just waking with the GPIO input.
	pinMode(PIN_LSM6DS3TR_C_INT1, INPUT_PULLDOWN_SENSE);

  return;
}

void setup()
{
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  
  digitalWrite(LED_RED, HIGH);
  digitalWrite(LED_GREEN, HIGH);

  QSPIF_sleep();

  // Flash green to see power on, reset, and wake from system_off
  digitalWrite(LED_GREEN, LOW);
  delay(1000);
  digitalWrite(LED_GREEN, HIGH);;

  // Minimizes power when bluetooth is used
  NRF_POWER->DCDCEN = 1;
}

void loop()
{
  // FreeRTOS will automatically put the system in system_on sleep mode here
  delay(10000); // Measure idle loop power during this period

  // Flash red before system_off sleep
  digitalWrite(LED_RED, LOW);
  delay(1000);
  digitalWrite(LED_RED, HIGH);;

  // Setup up double tap interrupt to wake back up
  setupWakeUpInterrupt();

  // Execution should not go beyond this
  NRF_POWER->SYSTEMOFF=1;
}

The Led will turn green when it wakes up ! :grin: