Blocking interupts and using the display

[rhubarbdog]

I have a DHT11 thermometer, it only works with microbit micropython is as an assembly routine with blocked interupts. if i use a print statement to show the result it works ok, if i use display.scroll there is a 15 second delay between the program starting and reading the sensor and the result being shown on the microbit display.

from microbit import *

@micropython.asm_thumb
def block_irq():
    cpsid('i')          # disable interrupts to go really fast                  

@micropython.asm_thumb
def unblock_irq():
    cpsie('i')          # enable interupts nolonger time critical               

block_irq()
# read sensor                                                                   
sleep(1000)
unblock_irq()
print('Microbit')

this program displays the word Microbit after 1 second when ran from a serial terminal, where as the following program takes about 15 seconds to display the word Microbit on the led display.

from microbit import *

@micropython.asm_thumb
def block_irq():
    cpsid('i')          # disable interrupts to go really fast                  

@micropython.asm_thumb
def unblock_irq():
    cpsie('i')          # enable interupts nolonger time critical               

block_irq()
# read sensor                                                                   
sleep(1000)
unblock_irq()
display.scroll('Microbit')

is there any way to use the display if interrupt blocking is required?

[microbit-carlos]

@dpgeorge This issue is replicable with machine.disable_irq() as well, but only in V1, this works fine in V2:

from microbit import *
import machine

print("one")
state = machine.disable_irq()
print("two")
sleep(10) # with sleep < 6 ms it doesn't seem to trigger
print("three")
machine.enable_irq(state)
print("four")
# 🛑 We get stuck here for about 15 seconds
display.scroll('micro:bit')
print("five")

Any ideas why this might be happening and if it is fixable?

[microbit-carlos]

@dpgeorge this is not a blocker for the v1.1 release, but if it's an easy fix it'd be nice for get it in for the next release.

[dpgeorge]

I can't reproduce this issue. Trying with a V1 micro:bit (does it matter which hardware revision??) and the build from actions, microbitv1-micropython-2022-08-19-8d2138720fa2cdadbeebba8a8f0a72563b891f20.hex.zip, the above code by @microbit-carlos works OK for me. It works with a sleep of 10, 20 and 1000. It does not get stuck before the display.scroll().

[microbit-carlos]

I can confirm that this is no longer a problem in the latest MicroPython CI builds. Just to double check I tried it again in the Python Editor v1.0.1 release and replicates there, so we can close this as fixed in the next release 👍