Updates to IO Pi and Expander Pi documentation

Author: abelectronicsuk

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2023-02-04 Andrew Dorey 
+
+* 1.2.0 Updates to IO Pi and Expander Pi documentation.
+
 #### 2022-12-21 Andrew Dorey
 
 * 1.1.9 Fixed spelling and grammar in README files and comments.

ExpanderPi/README.md

@@ -165,6 +165,8 @@ ___
 The IO methods control the MCP23017 16 digital I/O channels on the Expander Pi. The MCP23017 chip is split into two 8-bit ports. Port 0 controls pins 1 to 8 while Port 1 controls pins 9 to 16. 
 When writing to or reading from a port the least significant bit represents the lowest numbered pin on the selected port.
 
+**Note:** Microchip recommends that pin 8 (GPA7) and pin 16 (GPB7) are used as outputs only. This change was made for revision D MCP23017 chips manufactured after June 2020. See the [MCP23017 datasheet](https://www.abelectronics.co.uk/docs/pdf/microchip-mcp23017.pdf) for more information.
+
 ___
 ```
 io_set_pin_direction(uint8_t pin, uint8_t direction):

IOPi/README.md

@@ -5,6 +5,8 @@ C++ Library to use with IO Pi Raspberry Pi expansion board from https://www.abel
 
 The example demo files can be found in /ABElectronics_CPP_Libraries/IOPi/demos 
 
+**Note:** Microchip recommends that pin 8 (GPA7) and pin 16 (GPB7) are used as outputs only. This change was made for revision D MCP23017 chips manufactured after June 2020. See the [MCP23017 datasheet](https://www.abelectronics.co.uk/docs/pdf/microchip-mcp23017.pdf) for more information.
+
 ### Downloading and Installing the library
 
 To download to your Raspberry Pi type in terminal: