Sensor Toolbox, Directional Shake demo

[eliotstock]

I can't make sense of the Directional Shake demo in the Sensor Toolbox. What I want to do is:

1. Play around with the threshold and debounce sliders to see what works for my application.

2. Measure the current consumed in the sleep state. I expect to see 6 - 10 micro amps, as per the datasheet.

3. Measure the current consumed in the wake state.

I don't see how to put the device into sleep mode. I can only control Standby vs. Active, and when's it's Active, it's always in Wake Mode.

I also can't get the MCU Status light to go green, no matter how low the threshold or debounce sliders. "Default Transient Settings" is unchecked.

Estimated sleep current is 0.524 mA. Why is this 1000 times higher than the datasheet indicates for triggering?

[reyes]

Hi Eliot,

You didn’t specify which board of the Sensor Toolbox you are using, I’m assuming that you are using the LFSTBEB845x, please correct e if I’m wrong.

Answering to your requests:

1. Using the Directional Shake DEMO you can modify the Threshold and the Debounce sliders, in order to do this, you need to set the device into Standby Mode, then Click on the “Reset” Button below the debounce slider, and then you can adjust the sliders, after this you net to click on “Set” button and “Active” the device.

Once you properly set the threshold and debounce sliders, you should be able to see the MCU and the rest of the Status light to go green after a shake event is detected.

2. It is true that in the MMA845x datasheet is mentioned a current consumption of 6uA, but only for Low Power Mode with the ODR set to 1.56Hz, 6.25Hz or 12.5Hz.

And this current consumption is only from the accelerometer, I’m not sure how you are measuring the current, but you are probably measuring the current consumption of the entire board.

3. Unfortunately, since the Directional Shake is a DEMO, you do not have access to set the device into sleep mode, in order to do this, you would need to use the “Full System Evaluation” screen from the Sensor Toolbox GUI.

Have a great day,
Jose

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