time library not working with cold boot

[kctowers]

I'm using a ESP32-S3-DEVKIT (WROOM-1 processor). My application (main.py) retrieves a Unix Epoch time from a cell tower and uses it as a call to time.localtime(cell_epoch) in order to set the processor time. Then I use the 8-tuple from time.localtime() later in my program. I do realize that the cell tower time is based from 1970 and micropython uses 2000, so I do a correction before setting the local clock.

If I load the code and execute it using the green RUN button in Thonny everything works fine. When I call time.localtime() I get the correct date and time. The problem happens when I cold boot the program using a power cycle, time.localtime() returns Jan 1, 2000, 0:0:0.

I'm obviously missing some startup code the Thonny is executing when I use the REPL interface. Any ideas how I fix this?

This is the startup output from micropython:
ESP-ROM:esp32s3-20210327
Build:Mar 27 2021
rst:0x1 (POWERON),boot:0xa (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:1
load:0x3fcd0108,len:0xf24
load:0x403b6000,len:0xc2c
load:0x403ba000,len:0x2d60
entry 0x403b61f4

Thanks

Kevin

[davefes]

My understanding is that rshell and Thonny will get the local time from the PC and use that. Get time from a cell tower? Are you using NTP or is there some other method?

If that is all you see after a power-on reset then you need some print statements to tell if something else is happening. Or, show us the script that you use to connect to the cell tower and get the time.

[kctowers]

The ESP32 is interfaced to a Blues Notecard. When it connects to a cell tower it returns the current local time in Unix Epoch format. I think I missread the docs...

I was assuming that calling time.localtime(secs) with a parameter, it would set the internal micropython clock. I think it just converts the secs parameter to the 8 tuple. Is this correct?

If so, how do I set the micropython internal timer so that when I call time.localtime() it returns the correct values?

[kctowers]

Figured it out. I need to use the following call to set the internal clock:

rtc.datetime(time.localtime(cell_clock - SECONDS_1970_TO_2000))

After that time.localtime() returns the current time.

Thanks

Kevin