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==Component Source Code==
==Component Source Code==
Please click here to download the component source project: [https://www.flowcode.co.uk/wiki/componentsource/FC_Comp_Source_IOEXP_PCF8574.fcfx FC_Comp_Source_IOEXP_PCF8574.fcfx]


Please click here to view the component source code (Beta): [https://www.flowcode.co.uk/FlowchartView/?wfile=componentsource/FC_Comp_Source_IOEXP_PCF8574.fcfx FC_Comp_Source_IOEXP_PCF8574.fcfx]
Please click here to view the component source code (Beta): [https://www.flowcode.co.uk/FlowchartView/?wfile=componentsource/FC_Comp_Source_IOEXP_PCF8574.fcfx FC_Comp_Source_IOEXP_PCF8574.fcfx]


==Detailed description==
==Detailed description==




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==Examples==
==Examples==




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==Macro reference==


{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
|-
| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''ReadPort'''
|-
| colspan="2" | Reads the value of the IO pins. 
|-
|-
| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-u8-icon.png]] - BYTE
| width="90%" style="border-top: 2px solid #000;" | ''Return''
|}




{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
|-
| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''WritePort'''
|-
| colspan="2" | Writes a value to the IO pins. 
|-
|-
| width="10%" align="center" | [[File:Fc9-u8-icon.png]] - BYTE
| width="90%" | Value
|-
| colspan="2" | Value to write. Range 0-255 
|-
| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-void-icon.png]] - VOID
| width="90%" style="border-top: 2px solid #000;" | ''Return''
|}




{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
|-
| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Initialise'''
|-
| colspan="2" |  
|-
|-
| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-void-icon.png]] - VOID
| width="90%" style="border-top: 2px solid #000;" | ''Return''
|}








==Property reference==


{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
==Macro reference==
|-
 
| width="10%" align="center" style="background-color:#D8C9D8;" | [[File:Fc9-prop-icon.png]]
===Initialise===
| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Properties'''
{| class="mtx-class-macrotable wikitable"
|-
|-
|-
| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
| width="10%" align="center" style="background-color:#EAE1EA;" | [[File:Fc9-conn-icon.png]]
| width="90%" class="mtx-class-macrohead" | '''Initialise'''
| width="90%" style="background-color:#EAE1EA; color:#4B008D;" | I²C Communications
|-
|-
| width="10%" align="center" | [[File:Fc9-type-16-icon.png]]
| width="90%" | Device Type
|-
|-
| colspan="2" |  
| colspan="2" |  
|-
|-
| width="10%" align="center" | [[File:Fc9-type-16-icon.png]]
| width="90%" | External Address
|-
|-
| colspan="2" | Selects the value of the three address pins for the MCP23S17. 
| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-void-icon.png]] - VOID
|-
| width="90%" style="border-top: 2px solid #000;" | ''Return''
| width="10%" align="center" | [[File:Fc9-type-16-icon.png]]
|}
| width="90%" | Channel
 
|-
| colspan="2" | Channel selection 
|-
| width="10%" align="center" | [[File:Fc9-type-7-icon.png]]
| width="90%" | Stop Delay
|-
| colspan="2" | On older microcontroller devices there is a potential for the I2C hardware channel to lock up if there is not  a 10ms delay between an I2C stop event and the next I2C start event.  Most modern microcontrollers will not have a problem so this property can be disabled to speed up the  I2C communications.  
|-
| width="10%" align="center" | [[File:Fc9-type-16-icon.png]]
| width="90%" | Baud Select
|-
| colspan="2" | Baud rate option selector 
|-
| width="10%" align="center" | [[File:Fc9-type-14-icon.png]]
| width="90%" | Baud Rate
|-
| colspan="2" | Baud rate to be used 
|-
| width="10%" align="center" | [[File:Fc9-type-5-icon.png]]
| width="90%" | SDA
|-
| colspan="2" | Pin used for SDA (data signal) 
|-
| width="10%" align="center" | [[File:Fc9-type-5-icon.png]]
| width="90%" | SCL
|-
| colspan="2" | Pin used for SCL (clock signal) 
|-
| width="10%" align="center" style="background-color:#EAE1EA;" | [[File:Fc9-conn-icon.png]]
| width="90%" style="background-color:#EAE1EA; color:#4B008D;" | Simulation
|-
|-
| width="10%" align="center" | [[File:Fc9-type-10-icon.png]]
| width="90%" | Label
|-
| colspan="2" |  
|-
| width="10%" align="center" | [[File:Fc9-type-7-icon.png]]
| width="90%" | Scope Traces
|-
| colspan="2" | Selects if the scope traces are automatically generated or not 
|-
| width="10%" align="center" | [[File:Fc9-type-7-icon.png]]
| width="90%" | Console Data
|-
| colspan="2" | Selects if the console data is automatically generated or not 
|-
| width="10%" align="center" | [[File:Fc9-type-16-icon.png]]
| width="90%" | API
|-
| colspan="2" |  
|}==Macro reference==


{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
===ReadPort===
{| class="mtx-class-macrotable wikitable"
|-
|-
| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''ReadPort'''
| width="90%" class="mtx-class-macrohead" | '''ReadPort'''
|-
|-
| colspan="2" | Reads the value of the IO pins. 
| colspan="2" | Reads the value of the IO pins. 
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{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
===WritePort===
{| class="mtx-class-macrotable wikitable"
|-
|-
| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''WritePort'''
| width="90%" class="mtx-class-macrohead" | '''WritePort'''
|-
|-
| colspan="2" | Writes a value to the IO pins. 
| colspan="2" | Writes a value to the IO pins. 
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| width="90%" style="border-top: 2px solid #000;" | ''Return''
| width="90%" style="border-top: 2px solid #000;" | ''Return''
|}
|}
{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
|-
| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Initialise'''
|-
| colspan="2" |  
|-
|-
| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-void-icon.png]] - VOID
| width="90%" style="border-top: 2px solid #000;" | ''Return''
|}




==Property reference==
==Property reference==


{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
{| class="mtx-class-macrotable wikitable"
|-
|-
| width="10%" align="center" style="background-color:#D8C9D8;" | [[File:Fc9-prop-icon.png]]
| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-prop-icon.png]]
| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Properties'''  
| width="90%" class="mtx-class-macrohead" | '''Properties'''  
|-
|-
|-
|-
| width="10%" align="center" style="background-color:#EAE1EA;" | [[File:Fc9-conn-icon.png]]
| width="10%" align="center" class="mtx-class-propfolder" | [[File:Fc9-conn-icon.png]]
| width="90%" style="background-color:#EAE1EA; color:#4B008D;" | I²C Communications
| width="90%" class="mtx-class-propfolder" | I²C Communications
|-
|-
|-
|-
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| colspan="2" | Pin used for SCL (clock signal) 
| colspan="2" | Pin used for SCL (clock signal) 
|-
|-
| width="10%" align="center" style="background-color:#EAE1EA;" | [[File:Fc9-conn-icon.png]]
| width="10%" align="center" class="mtx-class-propfolder" | [[File:Fc9-conn-icon.png]]
| width="90%" style="background-color:#EAE1EA; color:#4B008D;" | Simulation
| width="90%" class="mtx-class-propfolder" | Simulation
|-
|-
|-
|-

Latest revision as of 14:37, 13 July 2026

Author Matrix TSL
Version 1.0
Category General Input


IO Expander (PCF8574) component

Provides 8 digital input/output pins arranged into an 8-bit port using a I2C bus connection. Up to eight expanders can be connected to the same I2C peripheral by means of three address pins. Supports the PCF8574 and PCF8574A devices allowing up to 16 expanders to be connected to the same I2C bus ( 8 x PCF8574 + 8 x PCF8574A ).

Component Source Code

Please click here to download the component source project: FC_Comp_Source_IOEXP_PCF8574.fcfx

Please click here to view the component source code (Beta): FC_Comp_Source_IOEXP_PCF8574.fcfx

Detailed description

No detailed description exists yet for this component

Examples

No additional examples







Macro reference

Initialise

Initialise
 
- VOID Return


ReadPort

ReadPort
Reads the value of the IO pins. 
- BYTE Return


WritePort

WritePort
Writes a value to the IO pins. 
- BYTE Value
Value to write. Range 0-255 
- VOID Return


Property reference

Properties
I²C Communications
Device Type
 
External Address
Selects the value of the three address pins for the MCP23S17. 
Channel
Channel selection 
Stop Delay
On older microcontroller devices there is a potential for the I2C hardware channel to lock up if there is not a 10ms delay between an I2C stop event and the next I2C start event. Most modern microcontrollers will not have a problem so this property can be disabled to speed up the I2C communications.  
Baud Select
Baud rate option selector 
Baud Rate
Baud rate to be used 
SDA
Pin used for SDA (data signal) 
SCL
Pin used for SCL (clock signal) 
Simulation
Label
 
Scope Traces
Selects if the scope traces are automatically generated or not 
Console Data
Selects if the console data is automatically generated or not 
API
 
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