Weird observation: In 18.7% it waks from deepsleep(2000). In the majority of cases it wakes form WDT(5000). As the deepsleep is 3 seconds shorter in this test progam than the WDT, it should always wake form depesleep (100%)
I guess there is some race condition in programming the wake timers. Any help is appreciated. Obviously this unpredictible behaviour is not giving sufficient reassurance to build a remote sensor that should be able to perform unattended for years.
@tschili Imho, if you trigger the wake-up just when the transmission starts, you'll have the issue that the GPY needs to little bit of time to wake-up and initialise, and you will most certainly lose and data received during that time.
So you would need the SIM800L to wait until the GPY is ready to receive before it start sending the data, and some other way to wake up the GPY.
@chrisi if you are using the Deep Sleep shield, then you have the relevant functions in the library that goes with it.
If you are using a Pysense (and I believe the same applies to the Pytrack), then it's a lot more complex. There's only one usable pin on the I/O header, you need to patch the Pysense firmware, isolate a pin between the module and the Pysense, and change a few things in the sleep process. But it does work.