Run 2 programs in succession

[PatLub85]

I would like to know if it is possible to make an ESP works in the following way:

• boot, launch of program 1 (main.py?)
• presses a push button, launches program 2, with release of program 1 and dependencies
• presses a push button, launches program 1, with release of program 2 and dependencies
• etc ...
  The idea is that each program has the maximum memory.
  But how to keep the previous state of the push button?
  Thanks in advance

[2dof]

Read/do some examples from micropython-async about asyncio tasks.
best start form libs for push/switch button

your program button switching function is just description of J-K flip-flop functionality (without clock) . in simplest pure code realisation will be like (as button calback)
(pseudo code)

state_flag =  False   # some global flaf

def  pushBtn_callbac(): 
      global state_flag
       
      state_flag = not state_flag

     if state_flag:
       # terminate program 1 (task cancel) and safe program states (if needed) 
       # run program 2  (  see  asyncio.create_task)
     else:
       # terminate program 2 
       # run program 1 

for memory cleaning use garbage collector

[PatLub85]

This seems like a good idea to me. I will test machine.RTC.memory.
Thank you for your help

[glenn20]

NP. Oh, one thing - machine.RTC.memory is currently undocumented. You can use it to write a bytes or bytearray object into RTC memory and read it back after a reboot (of course this is lost on a power cycle). An example of usage (untested code):

import machine

rtc = machine.RTC()
app_names = ("app_1", "app_2", "app_3")
app_num = (rtc.memory() or b"\x00")[0]  # Select first app if no value stored
next_app_num = (app_num + 1) % len(app_names)
rtc.memory(bytearray([next_app_num]))  # Save the next app num into RTC memory

# Load interrupt handlers for pins with handlers which call machine.soft_reset() on 
# button press or flag the app to cleanup and then reset

__import__(app_names[app_num])  # Import the app

Note that RTC memory is cleared on machine.hard_reset(), but you can use machine.soft_reset() or machine.deepsleep(1).

If you want to save some other state between resets you could encode that into the bytearray with json, struct or uctypes. The max length of data you can store is 2048 bytes (but can be changed by recompiling micropython).

[PatLub85]

Thanks Glenn,
I think you have the solution to my problem. I will test this next week

[PatLub85]

I don't understand why the '% len(app_names)'

[PatLub85]

sorry, I understood. This allows next_app_num to return to 0