Use distinctive names for SPI pin macros to avoid collisions

The "ArduinoISP" example allows the user to define arbitrary pins for use as the signal pins on the programmer board.
This is done via a set of macros.

Previously, very generic names were used for these macros. This resulted in a name collision. The core for the Renesas
boards also defines macros of the same name. Despite what the names might lead us to believe, the values of these macros
in the core do not match the Arduino pin numbers of the SPI bus. The result was that, with the default configuration of
the sketch where the USE_OLD_STYLE_WIRING macro is not defined, the sketch uses the values of the macros defined by the
core as the SPI signal pins instead of the standard SPI signal pins as the user would expect when the sketch is running
on an UNO R4 Minima, UNO R4 WiFi, or Portenta C33 board. This causes operations using the programmer to fail with an
error like:

avrdude: stk500_recv(): programmer is not responding avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x03
[...]

The name collision is avoided by adding a "namespace" prefix to the macro names.

Author: per1234

examples/11.ArduinoISP/ArduinoISP/ArduinoISP.ino

@@ -22,8 +22,8 @@
 // using an Uno. (On an Uno this is not needed).
 //
 // Alternatively you can use any other digital pin by configuring
-// software ('BitBanged') SPI and having appropriate defines for PIN_MOSI,
-// PIN_MISO and PIN_SCK.
+// software ('BitBanged') SPI and having appropriate defines for ARDUINOISP_PIN_MOSI,
+// ARDUINOISP_PIN_MISO and ARDUINOISP_PIN_SCK.
 //
 // IMPORTANT: When using an Arduino that is not 5V tolerant (Due, Zero, ...) as
 // the programmer, make sure to not expose any of the programmer's pins to 5V.
@@ -82,9 +82,9 @@
 
 #ifdef USE_OLD_STYLE_WIRING
 
-#define PIN_MOSI 11
-#define PIN_MISO 12
-#define PIN_SCK 13
+#define ARDUINOISP_PIN_MOSI 11
+#define ARDUINOISP_PIN_MISO 12
+#define ARDUINOISP_PIN_SCK 13
 
 #endif
 
@@ -100,20 +100,20 @@
 #endif
 
 // By default, use hardware SPI pins:
-#ifndef PIN_MOSI
-#define PIN_MOSI MOSI
+#ifndef ARDUINOISP_PIN_MOSI
+#define ARDUINOISP_PIN_MOSI MOSI
 #endif
 
-#ifndef PIN_MISO
-#define PIN_MISO MISO
+#ifndef ARDUINOISP_PIN_MISO
+#define ARDUINOISP_PIN_MISO MISO
 #endif
 
-#ifndef PIN_SCK
-#define PIN_SCK SCK
+#ifndef ARDUINOISP_PIN_SCK
+#define ARDUINOISP_PIN_SCK SCK
 #endif
 
 // Force bitbanged SPI if not using the hardware SPI pins:
-#if (PIN_MISO != MISO) || (PIN_MOSI != MOSI) || (PIN_SCK != SCK)
+#if (ARDUINOISP_PIN_MISO != MISO) || (ARDUINOISP_PIN_MOSI != MOSI) || (ARDUINOISP_PIN_SCK != SCK)
 #undef USE_HARDWARE_SPI
 #endif
 
@@ -186,11 +186,11 @@ private:
 class BitBangedSPI {
 public:
   void begin() {
-    digitalWrite(PIN_SCK, LOW);
-    digitalWrite(PIN_MOSI, LOW);
-    pinMode(PIN_SCK, OUTPUT);
-    pinMode(PIN_MOSI, OUTPUT);
-    pinMode(PIN_MISO, INPUT);
+    digitalWrite(ARDUINOISP_PIN_SCK, LOW);
+    digitalWrite(ARDUINOISP_PIN_MOSI, LOW);
+    pinMode(ARDUINOISP_PIN_SCK, OUTPUT);
+    pinMode(ARDUINOISP_PIN_MOSI, OUTPUT);
+    pinMode(ARDUINOISP_PIN_MISO, INPUT);
   }
 
   void beginTransaction(SPISettings settings) {
@@ -204,11 +204,11 @@ public:
 
   uint8_t transfer(uint8_t b) {
     for (unsigned int i = 0; i < 8; ++i) {
-      digitalWrite(PIN_MOSI, (b & 0x80) ? HIGH : LOW);
-      digitalWrite(PIN_SCK, HIGH);
+      digitalWrite(ARDUINOISP_PIN_MOSI, (b & 0x80) ? HIGH : LOW);
+      digitalWrite(ARDUINOISP_PIN_SCK, HIGH);
       delayMicroseconds(pulseWidth);
-      b = (b << 1) | digitalRead(PIN_MISO);
-      digitalWrite(PIN_SCK, LOW);  // slow pulse
+      b = (b << 1) | digitalRead(ARDUINOISP_PIN_MISO);
+      digitalWrite(ARDUINOISP_PIN_SCK, LOW);  // slow pulse
       delayMicroseconds(pulseWidth);
     }
     return b;
@@ -408,7 +408,7 @@ void set_parameters() {
 
 void start_pmode() {
 
-  // Reset target before driving PIN_SCK or PIN_MOSI
+  // Reset target before driving ARDUINOISP_PIN_SCK or ARDUINOISP_PIN_MOSI
 
   // SPI.begin() will configure SS as output, so SPI master mode is selected.
   // We have defined RESET as pin 10, which for many Arduinos is not the SS pin.
@@ -421,9 +421,9 @@ void start_pmode() {
 
   // See AVR datasheets, chapter "SERIAL_PRG Programming Algorithm":
 
-  // Pulse RESET after PIN_SCK is low:
-  digitalWrite(PIN_SCK, LOW);
-  delay(20);  // discharge PIN_SCK, value arbitrarily chosen
+  // Pulse RESET after ARDUINOISP_PIN_SCK is low:
+  digitalWrite(ARDUINOISP_PIN_SCK, LOW);
+  delay(20);  // discharge ARDUINOISP_PIN_SCK, value arbitrarily chosen
   reset_target(false);
   // Pulse must be minimum 2 target CPU clock cycles so 100 usec is ok for CPU
   // speeds above 20 KHz
@@ -439,8 +439,8 @@ void start_pmode() {
 void end_pmode() {
   SPI.end();
   // We're about to take the target out of reset so configure SPI pins as input
-  pinMode(PIN_MOSI, INPUT);
-  pinMode(PIN_SCK, INPUT);
+  pinMode(ARDUINOISP_PIN_MOSI, INPUT);
+  pinMode(ARDUINOISP_PIN_SCK, INPUT);
   reset_target(false);
   pinMode(RESET, INPUT);
   pmode = 0;