Hi, 

I stumbled across your question while searching for solutions for using this exact sensor with a Pico. 

Here's the Thonny code I pulled together that got the sensor working.

The top of the code has an i2c scan and outputting the addresses located. 

The binary address of mine is 64 - which is what's used in the code. 

If yours is different, you can update it accordingly. 

>> The biggest learning curve moment I had was converting the ‘0x00’ hex addresses into binary address ‘\x00’. I had the same EIO errors until I worked that out.

This code loops endlessly while pulling temp and humidity readings from the sensor.

I was holding the sensor in my hands, breathing on it to get the humidity and temperature to spike. 

##########THONNY SCRIPT###########

def calcTempFromBinary(binary):
   int_val = int.from_bytes(binary, "big")
   tempCalc = 165 * (int_val / (2**16-1)) - 40
   return tempCalc

def calcHumidityFromBinary(binary):
   int_val = int.from_bytes(binary, "big")
   humidityCalc = 100 * (int_val / (2**16-1))
   return humidityCalc

import machine
import time
sda=machine.Pin(16)
scl=machine.Pin(17)
i2c=machine.I2C(0,sda=sda, scl=scl, freq=400000)
#i2c=machine.I2C(0,sda=sda, scl=scl)

print('Scan i2c bus...')
devices = i2c.scan()

if len(devices) == 0:
   print("No i2c device !")
else:
   print('i2c devices found:',len(devices))

for device in devices:
   print("Decimal address: ",device," | Hexa address: ",hex(device))

addrDecimal = 64

while True:
   
   time.sleep(5)         #sleep 5 seconds
   
   i2c.writeto(addrDecimal, '\x00')     #request temperature read
   time.sleep(0.3)         #delay to allow temperature read
   tempBinary = i2c.readfrom(addrDecimal, 2)   #read bits from i2c
   
   temp = calcTempFromBinary(tempBinary)   #pass temperature binary to function for converstion
   
   i2c.writeto(addrDecimal, '\x01')    #request humidity read
   time.sleep(0.3)         #delay to allow humidity read
   tempBinary = i2c.readfrom(addrDecimal, 2)  #read bits from i2c
   
   humidity = calcHumidityFromBinary(tempBinary) #pass humidity binary to function for conversion
   
   print(f'Temperature is:{temp}  Humidity is:{humidity}')

______________________________

##########THONNY SCRIPT###########