Hi everyone,
I have been playing with LSM9DS1 for quite some time. Now I want to reduce its power consumption.
Currently Moteino + LSM9DS1 draws about 60mA. If I disabled gyro, mag and two of the axis of Accelerometer and the current draw has gone down to 35-40mA. On disconnecting the LSM9DS1 entirely, the same sketch consumes 2-10 mA. My Moteino draws about 10-50uA to send a data packet to a gateway.
LSM9DS1 should draw typically 4.5mA. Any idea where I am going wrong?
I have connected VDD, GND, SDA, and SCL directly.
Thanks in advance
Quote from: savan8192 on October 23, 2019, 12:19:51 PM
LSM9DS1 should draw typically 4.5mA. Any idea where I am going wrong?
The VDD you have is 3.3V, correct?
Is this the LSM9DS1 LPL Breakout (https://lowpowerlab.com/shop/product/186) ?
All boards go through some basic testing to ensure they power up and can yield valid readings. But I do not test for current draw.
Is there anything particularly visually suspect with the board (perhaps a bridge or something like that)?
Hi Felix, thanks for your reply.
Quote from: Felix on October 23, 2019, 10:39:38 PM
The VDD you have is 3.3V, correct?
Yes
Quote
Is this the LSM9DS1 LPL Breakout (https://lowpowerlab.com/shop/product/186) ?
Yes
Quote
All boards go through some basic testing to ensure they power up and can yield valid readings. But I do not test for current draw.
Board might be just fine, I may have to change the power mode in sketch?? - The datasheet mentions following
Quote
In the LSM9DS1 the accelerometer and gyroscope have two operating modes available:
only accelerometer active and gyroscope in power down or both accelerometer and
gyroscope sensors active at the same ODR. Switching from one mode to the other requires
one write operation: writing to CTRL_REG6_XL (20h), the accelerometer operates in
normal mode and the gyroscope is powered down, writing to CTRL_REG1_G (10h) both
accelerometer and gyroscope are activated at the same ODR.
Quote
Is there anything particularly visually suspect with the board (perhaps a bridge or something like that)?
Don't think so, attaching the picture for your reference - https://drive.google.com/file/d/1i1jMS1Yrxk49ASpEd0RGLaRP1JFHW6q_/view?usp=sharing
Board looks good,
Have you tried it without the breadboard? Sometimes breadboards can cause all kinds of problems.
Hi Felix, I have tried it without breadboard - on a Veroboard. I have sent you a PM.
Has this been solved meanwhile? If so, how?
I couldn't find the code to use the ST LSM9DS1 shield with the Moteino on https://github.com/LowPowerLab/LowPowerLab.github.io
Where is it?
There is no example code published there.
Here's an example sketch:
/*****************************************************************
SFE_LSM9DS1 Library Simple Example Code - I2C Interface
The LSM9DS1 is a versatile 9DOF sensor. It has a built-in
accelerometer, gyroscope, and magnetometer. Very cool!
This Arduino sketch is a demo of the simple side of the SFE_LSM9DS1 library.
It'll demo the following:
* How to create a LSM9DS1 object, using a constructor (global variables section).
* How to use the begin() function of the LSM9DS1 class.
* How to read the gyroscope, accelerometer, and magnetometer
using the readGryo(), readAccel(), readMag() functions and
the gx, gy, gz, ax, ay, az, mx, my, and mz variables.
* How to calculate actual acceleration, rotation speed,
magnetic field strength using the calcAccel(), calcGyro()
and calcMag() functions.
* How to use the data from the LSM9DS1 to calculate
orientation and heading.
This example demonstrates how to use I2C. The pin-out is as follows:
LSM9DS1 --------- Moteino
SCL ------------- SCL (A5 on Moteino/Arduino)
SDA ------------- SDA (A4 on Moteino/Arduino)
VDD ------------- 3.3V
GND ------------- GND
The LSM9DS1 has a maximum voltage of 3.6V. Make sure you power it
off the 3.3V rail! I2C pins are open-drain, so you'll be
(mostly) safe connecting the LSM9DS1's SCL and SDA pins
directly to a Moteino/Arduino.
Code by Jim Lindblom @ SparkFun Electronics
Adapted for MoteinoM0 by Felix Rusu, LowPowerLab.com
Original Creation Date: April 30, 2015
Distributed as-is; no warranty is given.
*****************************************************************/
// The SFE_LSM9DS1 library requires both Wire and SPI be
// included BEFORE including the 9DS1 library.
#include <Wire.h>
#include <SPI.h>
#include <SparkFunLSM9DS1.h>
// LSM9DS1 Library Init
// Use the LSM9DS1 class to create an object
LSM9DS1 imu;
// Example I2C Setup
// SDO_XM and SDO_G are both pulled high, so our addresses are:
#define LSM9DS1_M 0x1E // Would be 0x1C if SDO_M is LOW
#define LSM9DS1_AG 0x6B // Would be 0x6A if SDO_AG is LOW
// Sketch Output Settings
#define PRINT_CALCULATED
//#define PRINT_RAW
#define PRINT_SPEED 400 // 250 ms between prints
// Earth's magnetic field varies by location. Add or subtract
// a declination to get a more accurate heading. Calculate
// your's here:
// http://www.ngdc.noaa.gov/geomag-web/#declination
#define DECLINATION -8.58 // Declination (degrees) in Boulder, CO.
void setup()
{
pinMode(LED_BUILTIN,OUTPUT);
Serial.begin(115200);
delay(2000);
}
byte imuSetup() {
// Before initializing the IMU, there are a few settings
// we may need to adjust. Use the settings struct to set
// the device's communication mode and addresses:
imu.settings.device.commInterface = IMU_MODE_I2C;
imu.settings.device.mAddress = LSM9DS1_M;
imu.settings.device.agAddress = LSM9DS1_AG;
// The above lines will only take effect AFTER calling
// imu.begin(), which verifies communication with the IMU
// and turns it on.
if (!imu.begin())
{
Serial.println("Failed to communicate with LSM9DS1.");
/*
Serial.println("Double-check wiring.");
Serial.println("Default settings in this sketch will " \
"work for an out of the box LSM9DS1 " \
"Breakout, but may need to be modified " \
"if the board jumpers are.");
*/
return false;
}
return true;
}
void loop()
{
if (imuSetup()) {
printGyro(); // Print "G: gx, gy, gz"
printAccel(); // Print "A: ax, ay, az"
printMag(); // Print "M: mx, my, mz"
// Print the heading and orientation for fun!
// Call print attitude. The LSM9DS1's magnetometer x and y axes are opposite to the accelerometer, so my and mx are substituted for each other.
printAttitude(imu.ax, imu.ay, imu.az, -imu.my, -imu.mx, imu.mz);
Serial.println();
}
delay(PRINT_SPEED);
//imu.sleepGyro();
}
void printGyro()
{
// To read from the gyroscope, you must first call the
// readGyro() function. When this exits, it'll update the
// gx, gy, and gz variables with the most current data.
imu.readGyro();
// Now we can use the gx, gy, and gz variables as we please.
// Either print them as raw ADC values, or calculated in DPS.
Serial.print("G: ");
#ifdef PRINT_CALCULATED
// If you want to print calculated values, you can use the
// calcGyro helper function to convert a raw ADC value to
// DPS. Give the function the value that you want to convert.
Serial.print(imu.calcGyro(imu.gx), 2);
Serial.print(", ");
Serial.print(imu.calcGyro(imu.gy), 2);
Serial.print(", ");
Serial.print(imu.calcGyro(imu.gz), 2);
Serial.println(" deg/s");
#elif defined PRINT_RAW
Serial.print(imu.gx);
Serial.print(", ");
Serial.print(imu.gy);
Serial.print(", ");
Serial.println(imu.gz);
#endif
}
void printAccel()
{
// To read from the accelerometer, you must first call the
// readAccel() function. When this exits, it'll update the
// ax, ay, and az variables with the most current data.
imu.readAccel();
// Now we can use the ax, ay, and az variables as we please.
// Either print them as raw ADC values, or calculated in g's.
Serial.print("A: ");
#ifdef PRINT_CALCULATED
// If you want to print calculated values, you can use the
// calcAccel helper function to convert a raw ADC value to
// g's. Give the function the value that you want to convert.
Serial.print(imu.calcAccel(imu.ax), 2);
Serial.print(", ");
Serial.print(imu.calcAccel(imu.ay), 2);
Serial.print(", ");
Serial.print(imu.calcAccel(imu.az), 2);
Serial.println(" g");
#elif defined PRINT_RAW
Serial.print(imu.ax);
Serial.print(", ");
Serial.print(imu.ay);
Serial.print(", ");
Serial.println(imu.az);
#endif
}
void printMag()
{
// To read from the magnetometer, you must first call the
// readMag() function. When this exits, it'll update the
// mx, my, and mz variables with the most current data.
imu.readMag();
// Now we can use the mx, my, and mz variables as we please.
// Either print them as raw ADC values, or calculated in Gauss.
Serial.print("M: ");
#ifdef PRINT_CALCULATED
// If you want to print calculated values, you can use the
// calcMag helper function to convert a raw ADC value to
// Gauss. Give the function the value that you want to convert.
Serial.print(imu.calcMag(imu.mx), 2);
Serial.print(", ");
Serial.print(imu.calcMag(imu.my), 2);
Serial.print(", ");
Serial.print(imu.calcMag(imu.mz), 2);
Serial.println(" gauss");
#elif defined PRINT_RAW
Serial.print(imu.mx);
Serial.print(", ");
Serial.print(imu.my);
Serial.print(", ");
Serial.println(imu.mz);
#endif
}
// Calculate pitch, roll, and heading.
// Pitch/roll calculations take from this app note:
// http://cache.freescale.com/files/sensors/doc/app_note/AN3461.pdf?fpsp=1
// Heading calculations taken from this app note:
// http://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Defense_Brochures-documents/Magnetic__Literature_Application_notes-documents/AN203_Compass_Heading_Using_Magnetometers.pdf
void printAttitude(
float ax, float ay, float az, float mx, float my, float mz)
{
float roll = atan2(ay, az);
float pitch = atan2(-ax, sqrt(ay * ay + az * az));
float heading;
if (my == 0)
heading = (mx < 0) ? 180.0 : 0;
else
heading = atan2(mx, my);
heading -= DECLINATION * PI / 180;
if (heading > PI) heading -= (2 * PI);
else if (heading < -PI) heading += (2 * PI);
else if (heading < 0) heading += 2 * PI;
// Convert everything from radians to degrees:
heading *= 180.0 / PI;
pitch *= 180.0 / PI;
roll *= 180.0 / PI;
Serial.print("Pitch, Roll: ");
Serial.print(pitch, 2);
Serial.print(", ");
Serial.println(roll, 2);
Serial.print("Heading: "); Serial.println(heading, 2);
}