QUERY · ISSUE
Thread on Core 1 on PICO hangs when accessing io
bugport-rp2needs-info
Port, board and/or hardware
Raspberry Pi Pico
MicroPython version
MicroPython v1.23.0 on 2024-06-02; Raspberry Pi Pico with RP2040
Reproduction
import os
import time
import _thread
def core1_thread():
try:
print("entering core1_thread")
text = "some text to log"
# Open log file in append mode
f = open("test.log", "a")
f.write(text)
except OSError as ex:
print(ex)
finally:
f.close()
def create_log():
"""
Check if the log file exists. If the log file does not exist, create the log file and write a header line.
Parameters:
None
Returns:
None
"""
_log_fn = "/test.log"
try:
# File exists
os.stat(_log_fn)
return
except OSError:
idx = _log_fn.rfind("/")
dir = _log_fn[1:idx]
if dir and not dir in os.listdir():
os.mkdir(dir)
# File does not exist
try:
t = f"file {_log_fn} created\n"
with open(_log_fn, "a") as f:
f.write(t)
print(t.rstrip())
except OSError as ex:
raise OSError(f"exception {ex}")
def main():
create_log()
thread = _thread.start_new_thread(core1_thread, ())
if __name__ == "__main__":
main()
time.sleep(1) # if 'mpremote run', allow thread to run before we soft reset
Expected behaviour
Expected to see 'some text to log' in file test.log on pico.
Observed behaviour
After starting the thread it hangs after printing 'entering core1_thread'.
Additional Information
No, I've provided everything above.
Code of Conduct
Yes, I agree
CANDIDATE · ISSUE
rp2: No Pin IRQ on core 1 (on core 0: OK)
bugport-rp2
Port, board and/or hardware
RP2, PICO and PICO2, RP2040 and RP2350
MicroPython version
MicroPython v1.26.0 on 2025-08-09; Raspberry Pi Pico2 with RP2350
No Pin() IRQ when using the second core (_thread).
Primary core works as intended.
Reproduction
#!micropython
# -*- coding: UTF-8 -*-
# vim:fileencoding=UTF-8:ts=4
#╭──────────────────────────────────────────────────────────────────────────────╮
#│ PICO_THREAD_PIN_IRQ_TEST.PY │
#│ Board: PICO2/RP2350 │
#│ Micropython: 3.4.0; MicroPython v1.26.0 on 2025-08-09 │
#│ Testing: Pin.irq() on both cores │
#│ using a bridge between GPIO16 and GPIO17 │
#│ GPIO16 runs a slow PWM │
#│ GPIO17 acts as an input with IRQ │
#╰──────────────────────────────────────────────────────────────────────────────╯
import _thread
from sys import version
from array import array
from machine import Pin, PWM
from time import sleep_ms
_SIO_BASE = const(0xd0000000)
_CPUID = const(0x000 >>2)
_THREAD_HLT = const(0)
_THREAD_RUN = const(1)
_THREAD_FIN = const(2)
@micropython.viper
def cpuid() -> int:
sio: ptr32 = ptr32(_SIO_BASE)
return sio[_CPUID]
def core1(data,hard):
def cb_core1(pin):
print('cb_core1(): IRQ on core:', cpuid(), end=' ')
print('count:', data[1])
if data[1]:
data[1] -= 1
print('core1() is running on core:', cpuid())
pin = Pin(17, Pin.IN, Pin.PULL_UP)
data[1] = 5
pin.irq(handler=cb_core1, trigger=Pin.IRQ_FALLING, hard=hard)
while data[0] == _THREAD_RUN and data[1]:
sleep_ms(10)
pin.irq(None)
pin.init()
data[0] = _THREAD_FIN
return
def core0():
def cb_core0(pin):
print('cb_core0(): IRQ on core:', cpuid(), end=' ')
print('count:', data[1])
if data[1]:
data[1] -= 1
print(version)
data = array('I', (_THREAD_HLT,0)) # [0]state [1] counter
pwm = PWM(16, freq=10, duty_u16=2**15)
print('Testing hard=False on core 0')
pin = Pin(17, Pin.IN, None)
data[1] = 5
pin.irq(handler=cb_core0, trigger=Pin.IRQ_FALLING, hard=False)
while data[1]:
sleep_ms(10)
pin.irq(None)
pin.init()
print('Testing hard=True on core 0')
pin = Pin(17, Pin.IN, None)
data[1] = 5
pin.irq(handler=cb_core0, trigger=Pin.IRQ_FALLING, hard=True)
while data[1]:
sleep_ms(10)
pin.irq(None)
pin.init()
print('Testing hard=False on core 1')
data[0] = _THREAD_RUN
_thread.start_new_thread(core1, (data,False))
loops = 100
while (loops:= loops-1) and data[0] != _THREAD_FIN:
sleep_ms(10)
data[0] = _THREAD_HLT
while data[0] != _THREAD_FIN: pass
print('Testing hard=True on core 1')
data[0] = _THREAD_RUN
_thread.start_new_thread(core1, (data,True))
loops = 100
while (loops:= loops-1) and data[0] != _THREAD_FIN:
sleep_ms(10)
data[0] = _THREAD_HLT
while data[0] != _THREAD_FIN: pass
pwm.deinit()
core0()
3.4.0; MicroPython v1.26.0 on 2025-08-09
Testing hard=False on core 0
cb_core0(): IRQ on core: 0 count: 5
cb_core0(): IRQ on core: 0 count: 4
cb_core0(): IRQ on core: 0 count: 3
cb_core0(): IRQ on core: 0 count: 2
cb_core0(): IRQ on core: 0 count: 1
Testing hard=True on core 0
cb_core0(): IRQ on core: 0 count: 5
cb_core0(): IRQ on core: 0 count: 4
cb_core0(): IRQ on core: 0 count: 3
cb_core0(): IRQ on core: 0 count: 2
cb_core0(): IRQ on core: 0 count: 1
Testing hard=False on core 1
core1() is running on core: 1
Testing hard=True on core 1
core1() is running on core: 1
### Expected behaviour
Well, should fire IRQ/callback events when running on core 1.
### Observed behaviour
Does not.
### Additional Information
No, I've provided everything above.
### Code of Conduct
Yes, I agree