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sqfmi / Watchy

Watchy - An Open Source E-Ink Smartwatch
http://www.sqfmi.com
MIT License
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Using the BMA423 to trigger wakeup is slow #4

Open FWeinb opened 4 years ago

FWeinb commented 4 years ago

I just saw that you updated the code and included support for accessing the BMA423 accelerometer. Seeing the enableWakeupInterrupt got me interested in using that to wakeup the device. I have successfully adapted the Button_Test example to include the ACC_INT_1 (GPIO 25) as seen in the Schematic in the esp_sleep_enable_ext1_wakeup call which made it possible to react to it.

The issue I am facing is that initialising the BMA Sensor on every boot takes approx. 1-2s So I thought I would only need to do it on the first hard reset of the esp32 as the BMA sensor should keep it's config across reboots but that isn't working. If I don't initialise the BMA the ext1 wakeup is triggered all the time.

I looked into the implementation of the BMA423 sensor you provided and saw that you are uploading the config in the begin() call.

One "solution" I came up with is to do the init of the BMA on the second core of the esp32 but that seams unnecessarily complicated.

Do you have any pointers what I could try next?

FWeinb commented 4 years ago

I did some more research and found BoschSensortec/BMA423-Sensor-API which contains a much newer implementation. After adopting the BMA Class to this version (and fixing the timing functions, the _dev.delay pointer now expects a delay function that delays for microseconds instead of milliseconds).

After that was done I added a boolean flag to the begin() function to indicate if a full initialisation to conditionally uploaded the config.

If you are interested I could contribute my implementation to this repository (the API of the BMA class did slightly change though)

sqfmi commented 3 years ago

Thanks! We just updated the library, any pull requests are welcome! We do plan to move to the latest implementation from Bosch, expecting sometime in Q1 2021

LeonMatthes commented 3 years ago

The issue here is most likely that you didn't reset the interrupt. If you read the interrupt flags from the BMA they get reset.

With the newest version of the Bosch Sensortech lib, call bma423_read_int_status.

In this case the BMA can keep it's config. It's a bit unintuitive...

@sqfmi This should probably be done automatically before entering deep sleep in the Watchy library. Otherwise the interrupt will "stick" to HIGH, waking the ESP up all the time.