Count deepsleep event? (without using flash)
My device wakes up every few minutes from deepsleep checks a sensor and then goes back to deepsleep.
Now I want to send a lora message every hour about its status.
The problem is that I need some sense of relative past time after each wake up. (so I know it's time to send the update again)
I don't want to use flash since that would mean that the device writes every 1 or 2 minutes to that flash so I need some ram.
I only need a counter since I know it was sleeping for the time I set it, so every count is x minutes.
The ULP has ram that doesn't get erased during deepsleep, can I write and read 1 byte to it via python?
A solution I think of is that I change the year +1 for every wake-up and reset it when I reach the number of counts to send the lora message. (obviously having access to a byte from ULP would be much better)
Every 2 hour lora update and 1 minute sleep cycles means I have enough with a counter that goes up to 120, so even 7 bits is also ok.
Another solution is to send a message between minute 58 and 60 but then I will miss some messages or maybe have two. (so I don't want to do that)
Those write to flash, but use wear-levelling methods. The advantage is they'll survive more conditions than RTC.
Nevermind I figured it out:
import CountDeepSleep print('Counting: ' + str(CountDeepSleep.NumberofDeepSleepWakeUps())) if CountDeepSleep.RunSpecialEvent() : print ('Count reached') else: machine.deepsleep(3000)
from machine import RTC rtc = RTC() ResetOnCount = 4 # constant value def StoreCount(NewCount): rtc.memory(str(NewCount)) # update RTC RAM memory WakeUps = NewCount def ResetCount(): rtc.memory('0') WakeUps = 0 def NumberofDeepSleepWakeUps(): return WakeUps def RunSpecialEvent(): return WakeUps >= ResetOnCount if rtc.memory().decode() == '' : # power on WakeUps = 1 else: WakeUps = int(rtc.memory()) + 1 # wake from deepsleep if WakeUps >= ResetOnCount : rtc.memory('0') # Reset, keep 'WakeUps' on the max value for this wake up else: StoreCount(WakeUps) # update RTC RAM memory