Port Expander PCA9554

[uwe-48]

I have a problem with the control of a PCA9554 (I2C) with Micropython (version 1.13) by a NodeMCU module (ESP8266)
Here I have changed a module (PCA9554.PY, __init__, akael "ported" by theshade, 02.09.2019) a little bit.

When starting main.py I get the following error message:
AttributeError: 'module'object has no attribute'PCA9554
I looked it up on the net, but did not find a solution.

I attach all three files if possible.
The examples from Mike Causer for the MCP23017 and PCF8574 work. I can switch one LED on or off at a time.
What have I missed or what is wrong?

Code: Select all

[/# 23.10.2020

from  machine  import  Pin , I2C 
import pca9554
import time

i2c  =  I2C ( scl = Pin ( 5 ), sda = Pin ( 4 ), freq = 100000)
pca  =  pca9554 . PCA9554 (i2c, 0x25)

pca.setoutput()
pca.writebyte(0x00)

while True:
    pca.writebyte(0x00)
    time.sleep (1)
    pca.writebyte(0xff)
    time.sleep (1)]
    
    
    
    [code][/"""
MicroPython PCA9554 8-Bit I2C I/O Expander with Interrupt
Quelle:

################################################################################
# Author			: akael "ported" by theshade
# Creation date 		: 02.02.2019
# Langage			: microPython
# Filename			: pca9554.py
# Target		 		: Pycom pyscan
# Description		: PCA9554A GPIO Expander
################################################################################
23.10.2020
Anpassung an PCA9554 (Init)
"""
import time
from maschine import I2C

class PCA9554():
  
  #Define register
    Pca9554_IN_REG  = const(0x00) #Input register
    Pca9554_OUT_REG = const(0x01) #Output register
    Pca9554_POL_REG = const(0x02) #Polarity inversion register (1=data inverted)
    Pca9554_DIR_REG = const(0x03) #Config register (0=output, 1=input)
    Pca9554_I2CADDR = const(0x25)
    
    
    def __init__(self, i2c, address=0x25):
        self._i2c = i2c
        self._address = address
        self._port = bytearray(1)
        if i2c.scan().count(address) == 0:
            raise OSError('PCA9554 not found at I2C address {:#x}'.format(address))
   
  
        #"""set bit as output"""
    def setoutput(self):
        print('setting output to')
        currentvalue = self.i2c.readfrom_mem(Pca9554_I2CADDR , Pca9554_DIR_REG, 1)
        print(currentvalue[0] | (0x01<<self.line))
        self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_DIR_REG , currentvalue[0] & 255-(1<<self.line))

        #"""set bit as input"""
    def setinput(self):
        print('setting input to')
        currentvalue = self.i2c.readfrom_mem(Pca9554_I2CADDR , Pca9554_DIR_REG, 1)
        print(currentvalue[0] | (0x01<<self.line))
        self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_DIR_REG ,currentvalue[0] | (0x01<<self.line))
        #self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_DIR_REG , self.line)

    def writebyte(self,value):
         #"""write output byte value"""
		    self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_OUT_REG, value)
		    return
        
    def readbyte(self):
        #"""read input byte value"""
        return self.i2c.readfrom_mem(Pca9554_I2CADDR, Pca9554_IN_REG,1)
        
    def set(self):
        #"""set output bit at 1"""
        currentvalue = self.i2c.readfrom_mem(Pca9554_I2CADDR, Pca9554_OUT_REG,1)
        #self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_OUT_REG, 1<<2)
        self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_OUT_REG, currentvalue[0] | 1<<self.line)

    def reset(self):
         #"""reset output bit at 0"""
		    currentvalue = self.i2c.readfrom_mem(Pca9554_I2CADDR, Pca9554_OUT_REG,1)
		    self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_OUT_REG, currentvalue[0] & (255-(1<<self.line)))
		    return
        
    def get(self):
        #"""read input bit value"""
		    linevalue = self.i2c.readfrom_mem(Pca9554_I2CADDR, Pca9554_IN_REG,1)
		    ret = ((linevalue >> self.line) & 1 )
		    return ret  ]

[jimmo]

It sounds like either the pca9554.py file isn't properly copied to the device, or can't be imported correctly.

How are you copying the files to the device?

[uwe-48]

It sounds like either the pca9554.py file isn't properly copied to the device, or can't be imported correctly.

How are you copying the files to the device?

I use the IDE uPyCraft V1.1 and copied three files (boot.py, main.py, pca9554.py)
via download into the device. I can also read these files back from the device.
So the required file should be available.

[rpr]

In your file pca9554.py I see the following typo:

Code: Select all

from maschine import I2C

Not sure if that is causing the issues.

[uwe-48]

Thanks for the hint, unfortunately it does not solve the problem.
With the simple I2C commands I can change the state of the outputs,
but not with this variant. I will test another hardware variant.

[uwe-48]

Hello,
I have now built and tested my circuit with a D1 mini (ESP8266EX) and a MCP23017 and a PCA9554. The software works for the MCP23017, but the PCA9554 seems to only run the i2c.scan(). The SDA and SCL signals can be displayed using a logic analyser (salae clone). In the module "pca9554.py) there is still the expression "self.line" from the old source. Does anything need to be changed here, are there any suggestions?

Thanks

[uwe-48]

Hello, I have changed my test programme, but unfortunately it still does not work.
I don't get an error message on startup anymore, a "T" is now displayed in the output
window on startup, the program still outputs "stat1" and then nothing happens.
Does anyone have an idea? Translate with DeepL

Code: Select all

[/"""
MicroPython PCA9554 8-Bit I2C I/O Expander with Interrupt


Quelle:

################################################################################
# Author			: akael "ported" by theshade
# Creation date 		: 02.02.2019
# Langage			: microPython
# Filename			: pca9554.py
# Target		 		: Pycom pyscan
# Description		: PCA9554A GPIO Expander
################################################################################


23.10.2020
Anpassung an PCA9554 (Init)
"""
#import time
#from machine import I2C



class PCA9554:
  
  #Define register
    Pca9554_IN_REG  = const(0x00) #Input register
    Pca9554_OUT_REG = const(0x01) #Output register
    Pca9554_POL_REG = const(0x02) #Polarity inversion register (1=data inverted)
    Pca9554_DIR_REG = const(0x03) #Config register (0=output, 1=input)
    Pca9554_I2CADDR = const(0x21)
    
    
    def __init__(self, i2c, address=0x21):
        self._i2c = i2c
        self._address = address
        self._port = bytearray(1)
        if i2c.scan().count(address) == 0:
            raise OSError('PCA9554 not found at I2C address {:#x}'.format(address))
   
  
        #"""set bit as output"""
    def setoutput(self):
        print('setting output to')
        currentvalue = self.i2c.readfrom_mem(Pca9554_I2CADDR , Pca9554_DIR_REG, 1)
        print(currentvalue[0] | (0x01<<self._port))
        self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_DIR_REG , currentvalue[0] & 255-(1<<self._port))

        #"""set bit as input"""
    def setinput(self):
        print('setting input to')
        currentvalue = self.i2c.readfrom_mem(Pca9554_I2CADDR , Pca9554_DIR_REG, 1)
        print(currentvalue[0] | (0x01<<self._port))
        self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_DIR_REG ,currentvalue[0] | (0x01<<self._port))
        #self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_DIR_REG , self.line)

    def writebyte(self,value):
         #"""write output byte value"""
		    self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_OUT_REG, value)
		    return
        
    def readbyte(self):
        #"""read input byte value"""
        return self.i2c.readfrom_mem(Pca9554_I2CADDR, Pca9554_IN_REG,1)
        
    def set(self):
        #"""set output bit at 1"""
        currentvalue = self.i2c.readfrom_mem(Pca9554_I2CADDR, Pca9554_OUT_REG,1)
        #self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_OUT_REG, 1<<2)
        self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_OUT_REG, currentvalue[0] | 1<<self.port)

    def reset(self):
         #"""reset output bit at 0"""
		    currentvalue = self.i2c.readfrom_mem(Pca9554_I2CADDR, Pca9554_OUT_REG,1)
		    self.i2c.writeto_mem(Pca9554_I2CADDR, Pca9554_OUT_REG, currentvalue[0] & (255-(1<<self._port)))
		    return
        
    def get(self):
        #"""read input bit value"""
		    linevalue = self.i2c.readfrom_mem(Pca9554_I2CADDR, Pca9554_IN_REG,1)
		    ret = ((linevalue >> self._port) & 1 )
		    return ret]
		    
		    [
# 05.11.2020


from  machine  import  Pin , I2C 
import pca9554
import time


i2c  =  I2C ( scl = Pin ( 5 ), sda = Pin ( 4 ), freq = 100000)
pca  =  pca9554.PCA9554 (i2c, 0x21)

print('stat0')

time.sleep (1)
pca.setoutput(0)

print('stat1')

while True:
  pca.writebyte(0x00)
  print('stat2')
  #pca.set()
  time.sleep (1)
  pca.writebyte(0xff)
  print('stat3')
  #pca.reset()
  time.sleep (1)]