I2C readfrom_mem throws EPERM on Portenta C33 #13280
Description
I'm on MicroPython v1.22.0 on 2023-12-27; Arduino Portenta C33 with RA6M5 and I just ran
a simple I2C read that worked fine under 1.21 (after merging #12978). It now throws an exception EPERM. It does however still work with SoftI2C.
I wonder what changed in the mean time in the Renesas port 🤔
To reproduce it, run the following with the values adjusted for you I2C peripheral:
from machine import I2C, Pin, SoftI2C
buses = [I2C(0), SoftI2C(scl=Pin('P408') , sda=Pin('P407'))]
for bus in buses:
print("Trying bus", bus)
try:
data = bus.readfrom_mem(0x21, 0x1c, 0x1)
print(data)
print("Success on bus", bus)
except Exception as e:
print(f"Read failed on bus {bus}: {e}")
With my setup it prints the following:
Trying bus I2C(0, freq=400000, scl=P408, sda=P407)
Read failed on bus I2C(0, freq=400000, scl=P408, sda=P407): [Errno 1] EPERM
Trying bus SoftI2C(scl=P408, sda=P407, freq=500000)
b'\xb8'
Success on bus SoftI2C(scl=P408, sda=P407, freq=500000)