Hello,
I am coding on a Seeed Xiao NRF52840 Sense, with the LSM6DS3 6-axis chip. I was wanting to write some code on possibly putting the chip into power off mode, but then when a significant motion is detected by the LSM6DS3, if that would be able to wake it up into the power on mode?
Currently I am using the Arduino IDE, with the appropriate libraries and I am coding on a MAC.
I have seen this ticket which wakes up from a double tap, but i was wondering if there was a way to make it wakeup from any "significant Motion found in the high level example for the LSM6DS3, the code snippets I am referencing will be located below.
Any help would be appreciated.
This is the Double tap to wakeup from an interrupt.
/*****************************************************************************/
// IMU Interrupt Example for XIAO BLE Sense
// This example shows how to configure LMSD6S3TR-C on XIAO BLE SENSE to interrupt
// on INT1 after a "Double Tap" was recognized.
// Additionally, the device goes into System OFF state, after 5 interrupts were
// received. Another "Double Tap" will wake up the device again.
//
// by chuck
/*******************************************************************************/
#include "LSM6DS3.h"
#include "Wire.h"
LSM6DS3 myIMU(I2C_MODE, 0x6A);
#define int1Pin PIN_LSM6DS3TR_C_INT1
uint8_t interruptCount = 0; // Amount of received interrupts
uint8_t prevInterruptCount = 0; // Interrupt Counter from last loop
void setup() {
Serial.begin(9600);
pinMode(LEDR, OUTPUT);
pinMode(LEDG, OUTPUT);
pinMode(LEDB, OUTPUT);
setLedRGB(false, false, true); // set blue led
myIMU.settings.gyroEnabled = 0; // Gyro currently not used, disabled to save power
if (myIMU.begin() != 0) {
Serial.println("IMU error");
} else {
Serial.println("IMU OK!");
}
setupDoubleTapInterrupt();
pinMode(int1Pin, INPUT);
attachInterrupt(digitalPinToInterrupt(int1Pin), int1ISR, RISING);
}
void loop() {
setLedRGB(false, false, true); // reset led to blue only
Serial.print("\Iterrupt Counter: ");
Serial.println(interruptCount);
// if interrupt was received in this cycle
if (interruptCount > prevInterruptCount) {
Serial.println("\Interrupt received!");
setLedRGB(false, true, false); // set green only
}
prevInterruptCount = interruptCount;
if (interruptCount >= 5) {
// Trigger System OFF after 5 interrupts
goToPowerOff();
}
delay(500);
}
// -------------------- System ------------------------- //
void goToPowerOff() {
setLedRGB(false, false, false);
Serial.println("Going to System OFF");
setupDoubleTapInterrupt(); // not needed here, if already applied..
delay(100); // delay seems important to apply settings, before going to System OFF
//Ensure interrupt pin from IMU is set to wake up device
nrf_gpio_cfg_sense_input(digitalPinToInterrupt(int1Pin), NRF_GPIO_PIN_PULLDOWN, NRF_GPIO_PIN_SENSE_HIGH);
// Trigger System OFF
NRF_POWER->SYSTEMOFF = 1;
}
// -------------------- Interrupts ------------------------- //
void setupDoubleTapInterrupt() {
uint8_t error = 0;
uint8_t dataToWrite = 0;
// Double Tap Config
myIMU.writeRegister(LSM6DS3_ACC_GYRO_CTRL1_XL, 0x60);
myIMU.writeRegister(LSM6DS3_ACC_GYRO_TAP_CFG1, 0x8E);// INTERRUPTS_ENABLE, SLOPE_FDS
myIMU.writeRegister(LSM6DS3_ACC_GYRO_TAP_THS_6D, 0x8C);
myIMU.writeRegister(LSM6DS3_ACC_GYRO_INT_DUR2, 0x7F);
myIMU.writeRegister(LSM6DS3_ACC_GYRO_WAKE_UP_THS, 0x80);
myIMU.writeRegister(LSM6DS3_ACC_GYRO_MD1_CFG, 0x08);
}
void int1ISR()
{
interruptCount++;
}
// -------------------- Utilities ------------------------- //
void setLedRGB(bool red, bool green, bool blue) {
if (!blue) { digitalWrite(LEDB, HIGH); } else { digitalWrite(LEDB, LOW); }
if (!green) { digitalWrite(LEDG, HIGH); } else { digitalWrite(LEDG, LOW); }
if (!red) { digitalWrite(LEDR, HIGH); } else { digitalWrite(LEDR, LOW); }
}
This is the high level example with significant motion.
#include <LSM6DS3.h>
#include <Wire.h>
//Create a instance of class LSM6DS3
LSM6DS3 myIMU(I2C_MODE, 0x6A); //I2C device address 0x6A
float aX, aY, aZ, gX, gY, gZ;
const float accelerationThreshold = 2.5; // threshold of significant in G's
const int numSamples = 119;
int samplesRead = numSamples;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
while (!Serial);
//Call .begin() to configure the IMUs
if (myIMU.begin() != 0) {
Serial.println("Device error");
} else {
Serial.println("aX,aY,aZ,gX,gY,gZ");
}
}
void loop() {
// wait for significant motion
while (samplesRead == numSamples) {
// read the acceleration data
aX = myIMU.readFloatAccelX();
aY = myIMU.readFloatAccelY();
aZ = myIMU.readFloatAccelZ();
// sum up the absolutes
float aSum = fabs(aX) + fabs(aY) + fabs(aZ);
// check if it's above the threshold
if (aSum >= accelerationThreshold) {
// reset the sample read count
samplesRead = 0;
break;
}
}
// check if the all the required samples have been read since
// the last time the significant motion was detected
while (samplesRead < numSamples) {
// check if both new acceleration and gyroscope data is
// available
// read the acceleration and gyroscope data
samplesRead++;
// print the data in CSV format
Serial.print(myIMU.readFloatAccelX(), 3);
Serial.print(',');
Serial.print(myIMU.readFloatAccelY(), 3);
Serial.print(',');
Serial.print(myIMU.readFloatAccelZ(), 3);
Serial.print(',');
Serial.print(myIMU.readFloatGyroX(), 3);
Serial.print(',');
Serial.print(myIMU.readFloatGyroY(), 3);
Serial.print(',');
Serial.print(myIMU.readFloatGyroZ(), 3);
Serial.println();
if (samplesRead == numSamples) {
// add an empty line if it's the last sample
Serial.println();
}
}
}
