Wake machine.deepsleep using pin input from accelerometer [SOLVED]

[alexpul]

I'm trying to create an accelerometer interrupt for machine.deepsleep(). From what I can tell there is no built-in function for that. Since deep sleep can be interrupted with a pin I was thinking that there might be a pin that allows the accelerometer to relay an interrupt to the device.

I've tried P13, which is denoted as "Accelerometer Interrupt" on the Pytrack pinout but I didn't get a response (even when the device was not asleep). Here is the code I was using

from machine import Pin
​
def pin_handler(arg):
    print("got an interrupt in pin %s" % (arg.id()))
​
p_in = Pin('P13', mode=Pin.IN, pull=Pin.PULL_UP) 
p_in.callback(Pin.IRQ_FALLING, pin_handler)

Any ideas or suggestions would be great!

My system specs:

(sysname='WiPy', nodename='WiPy', release='1.18.0.r1', version='v1.8.6-849-9569a73 on 2018-07-20', machine='WiPy with ESP32', pybytes='0.9.0')

[jcaron]

@alexpul Did you configure the accelerometer (enable it, set it to monitor events and send interrupts)?

You need to at least instantiate the LIS2HH12 class, and call the enable_activity_interrupt method.

There may be more stuff to do. Check the sources of the PyTrack library for more information.

[alexpul]

@jcaron This is the code I've tried to test if the accelerometer can wake from machine.deepsleep()

from LIS2HH12 import LIS2HH12
import pycom
import machine
import utime

pycom.heartbeat(False)

def accel_activity_handler(pin_o):
    pycom.rgbled(0x800080)
    utime.sleep_ms(200)
    pycom.heartbeat(False)

## ACCELEROMETER INTERRUPT
acc = LIS2HH12()
acc.enable_activity_interrupt(1000, 200, handler=accel_activity_handler)

machine.deepsleep(100*1000)

When I shake the device nothing happens...

(Note that this script does allow for a deep sleep interrupt but only when pytrack.go_to_sleep() is used to enter deep sleep. I need to use machine.deepsleep() though..)

[jcaron]

@alexpul In that code you don't enable wake-on-pin, and you don't do anything visible before going back to sleep, so even if it wakes up you won't see anything...

Note that as far as I know, the handler will only be called if the interrupt happens while the device is awake, not during sleep.

Start by using acc.enable_activity_interrupt without any deep sleep to see if the interrupt gets triggered (i.e. just remove the machine.deepsleep in your code).

Once you have confirmed that, you can add the wake-on-pin, and do something visible when you wake up before going back to sleep.

[alexpul]

Ah ha. I was using the wrong interrupt script.

This is the correct working code for an accelerometer interrupt (P13) of machine.deepsleep():

import machine
machine.pin_deepsleep_wakeup(['P13'], machine.WAKEUP_ANY_HIGH, False)
machine.deepsleep(10*1000)

So for pin interrupts there is a callback() function to create interrupts of active and sleep modes but the pin_deepsleep_wakeup() is needed to interrupt deep sleep (is that what you meant by "wake-on-pin" @jcaron?). There is no interrupt handler for pin_deepsleep_wakeup() because the working memory is cleared after deep sleep (as mentioned by @jcaron below).

@jcaron I had tested my interrupt handler without sleep and it did work. In my main.py I had the following script to test that it woke from deep sleep and ran main.py.

import pycom
import utime

pycom.heartbeat(False)                      #turn off LED
pycom.rgbled(0xFF0000)                    #red LED
utime.sleep(2)
pycom.heartbeat(False)                      #turn off LED