Long Lasting Battery Life

ptsg

I'm currently working on a project that requires me to monitor the motion of a device. Ive used the commands (mbl_mw_acc_bosch_set_any_motion_count, mbl_mw_acc_bosch_set_any_motion_threshold) to get what i want but the battery life is around 24 hours. thats using 10 Hz for the odr.

What would be the required way to hanlde this ( i was hoping for a year at least.)

Laura

You will need to do a few things to save battery life:

• turn off all unused sensors
• use logging over streaming
• reduce the amount of bluetooth connections
• reduce sampling frequency

After that, if you have a MMR, you can use a battery pack like this one or solder a bigger lipo battery like these ones to get longer battery life.

ptsg

So what i Will do then is setup My gyro to:

            MetaWear.mbl_mw_gyro_bmi160_set_odr(device.board, 10.0); // 25Hz
            MetaWear.mbl_mw_gyro_bmi160_set_range(device.board, 4.0); //125dps

and then setup the Logger to store the values using the example from here:
https://github.com/mbientlab/MetaWear-SDK-JavaScript/blob/master/examples/logging.js

A few Questions:
1. Is there a way to tell how much power usage will be (on paper?)
2. Can i log for an entire day and read it once (a day)?
3. is there a way to log battery?

Thank you for your time!

ptsg

Also to Add to this: do you have a java script sample for mbl_mw_metawearboard_serialize and mbl_mw_logger_lookup_id since i cannot say for certain that the app will be running (or have a cycle) in between reads.

// Store the log event for later download.  If your program needs to terminate
// before performing the log download, you will need to use mbl_mw_metawearboard_serialize
// to store the device state and that pass that state as the second argument to
// connectAndSetUp when you are ready to download.  Use mbl_mw_logger_lookup_id
// to retrieve this accelLogger object

Laura

@ptsg said:

A few Questions:
1. Is there a way to tell how much power usage will be (on paper?)
2. Can i log for an entire day and read it once (a day)?
3. is there a way to log battery?

Thank you for your time!

1. No, you would have to calculate the power usage using standard electronic tools (DMM...)
2. Yes but you need to use our memory calculator to understand the limitations of sampling frequencies versus memory size. See our tutorials for this.
3. Yes, there is an API call to read the battery %, please see our developer portal.
4. Please see the tutorials and Java github page for examples. Again you should be looking into the documentation of our developer portal.