Changes specific to the use with ESP32 MCUs

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "C_Cpp.errorSquiggles": "disabled"
+}

MCP23S08.cpp

@@ -23,19 +23,15 @@ MCP23S08::MCP23S08(SPIClass & spi,
 
 
 void MCP23S08::begin() {
-	// Why do we initialize the pin here
-	// yet expect the spi bus to be initialized?
-	pinMode(csPin, OUTPUT);
+	/* Why do we initialize the pin here
+	yet expect the spi bus to be initialized?
+	Good question, not sure but, maybe the ESP32 SPI is not yet inialised.*/
+
+	pinMode(csPin, OUTPUT);		// Required for ESP32 devices.
 
 	// enable chip hardware addresses
 	if (haen) {
-		spi.beginTransaction(spi_settings);
-		digitalWrite(csPin, LOW);
-		spi.transfer(0x40);  // command write, address 0 (hardware addressing is disabled on POR)
-		spi.transfer(MCP23S08_IOCON);
-		spi.transfer(0x08);
-		digitalWrite(csPin, HIGH);
-		spi.endTransaction();
+		writeRegister(MCP23S08_IOCON, MCP23S08_IOCON_HAEN);
 	}
 }
 
@@ -49,7 +45,7 @@ void MCP23S08::reset() {
 	spi.transfer(0xFF);				// reset first register
 	for (uint8_t i = 0; i < MCP23S08_OLAT; i++) {
 		if (haen && (MCP23S08_IOCON == i))
-			spi.transfer(0x08);			// enable hardware address (HAEN)
+			spi.transfer(MCP23S08_IOCON_HAEN);			// enable hardware address (HAEN)
 		else
 			spi.transfer(0x00);			// reset other 10 registers
 	}

MCP23S08.h

@@ -10,6 +10,7 @@
 #ifndef __MCP23S08_h__
 #define __MCP23S08_h__
 
+#include "Arduino.h"		// Required for ESP32 devices.
 #include <SPI.h>
 
 
@@ -25,6 +26,7 @@
 #define MCP23S08_INTCAP		0x08
 #define MCP23S08_GPIO		0x09
 #define MCP23S08_OLAT		0x0A
+#define MCP23S08_IOCON_HAEN	0x08
 
 
 class MCP23S08 {