OSError: [Errno 5] EIO

[YachtMango]

Hi,

Tried to use this on a number of RP2040 based micro-controllers:

Pico W + hat that has STEMMA QT / Qwiic connector
Pimorono Pico Lipo
Pimoroni Badger.

All examples above can see the sht40 on I2C hexadecimal address: 0x44 so the wiring looks ok but as soon as I instantiate the sht40 object and get a reading I get.

MPY: soft reboot
Traceback (most recent call last):
File "", line 9, in
File "/lib/micropython_sht4x/sht4x.py", line 152, in measurements
OSError: [Errno 5] EIO

Typically this indicates a wiring issue but as noted the sht40 can be seen in i2c.

Researching this I found this same/similar but doesn't looked like they ever raised an issue?

https://github.com/orgs/micropython/discussions/14334

[jposada202020]

What kind of sensor are you using?

[YachtMango]

Adafruit Sensirion SHT40 Temperature & Humidity Sensor.

Using circuit python and the https://github.com/adafruit/Adafruit_CircuitPython_SHT4x it works reliably

However the rest of my project is on micropython so keen to get a working MP solution. TIA

[jposada202020]

Interesting, libraries are not that different. Could you try in your code a reset of the sensor. If this does not work need to see what happens with my sensor. (I do not have my MicroPython setup right now, as I wanted to work in some CircuitPython Projets this winter :) )

import time
from machine import Pin, I2C
from micropython_sht4x import sht4x

i2c = I2C(1, sda=Pin(2), scl=Pin(3))  # Correct I2C pins for RP2040
sht = sht4x.SHT4X(i2c)
sht.reset()

while True:
    temperature, relative_humidity = sht.measurements
    print(f"Temperature: {temperature:.2f}°C")
    print(f"Relative Humidity: {relative_humidity:.2%}%")
    print("")
    time.sleep(0.5)

[YachtMango]

Adding the reset() gives

Traceback (most recent call last):
File "", line 27, in
File "/lib/micropython_sht4x/sht4x.py", line 257, in reset
OSError: [Errno 110] ETIMEDOUT

If I handle the OSError: [Errno 5] EIO I can get readings but the count of the number of error keeps going up for each iteration