RPC: fix example to avoid using RPC raw

Author: facchinm

Diff for: libraries/RPC/examples/RPC_m4/RPC_m4.ino

@@ -1,13 +1,14 @@
 #include "Arduino.h"
 #include "RPC.h"
+#include "SerialRPC.h"
 
 using namespace rtos;
 
 Thread subtractThread;
 
 /**
- * Returns the CPU that's currently running the sketch (M7 or M4)
- * Note that the sketch has to be uploaded to both cores. 
+   Returns the CPU that's currently running the sketch (M7 or M4)
+   Note that the sketch has to be uploaded to both cores.
  **/
 String currentCPU() {
   if (HAL_GetCurrentCPUID() == CM7_CPUID) {
@@ -18,7 +19,7 @@ String currentCPU() {
 }
 
 /**
- * Adds two numbers and returns the sum
+   Adds two numbers and returns the sum
  **/
 int addOnM7(int a, int b) {
   Serial.println(currentCPU() + ": executing add with " + String(a) + " and " + String(b));
@@ -27,7 +28,7 @@ int addOnM7(int a, int b) {
 }
 
 /**
- * Subtracts two numbers and returns the difference
+   Subtracts two numbers and returns the difference
  **/
 int subtractOnM7(int a, int b) {
   Serial.println(currentCPU() + ": executing subtract with " + String(a) + " and " + String(b));
@@ -40,11 +41,11 @@ void callSubstractFromM4() {
     delay(700); // Wait 700ms with the next calculation
     int a = random(100); // Generate a random number
     int b = random(100); // Generate a random number
-    RPC.println(currentCPU() + ": calling subtract with " + String(a) + " and " + String(b));
-    
+    SerialRPC.println(currentCPU() + ": calling subtract with " + String(a) + " and " + String(b));
+
     auto result = RPC.call("remoteSubtract", a, b).as<int>();
     // Prints the result of the calculation
-    RPC.println(currentCPU() + ": Result is " + String(a) + " - " + String(b) + " = " + String(result));
+    SerialRPC.println(currentCPU() + ": Result is " + String(a) + " - " + String(b) + " = " + String(result));
   }
 }
 
@@ -53,18 +54,17 @@ void setup() {
   pinMode(LED_BUILTIN, OUTPUT);
 
   // Initialize RPC library; this also boots the M4 core
-  RPC.begin();
   Serial.begin(115200);
-  //while (!Serial) {} // Uncomment this to wait until the Serial connection is ready
-
-  // Both CPUs will execute this instruction, just at different times
-  randomSeed(analogRead(A0)); // Initializes the pseudo-random number generator
+  while (!Serial) {} // Uncomment this to wait until the Serial connection is ready
+  if (!SerialRPC.begin()) {
+    Serial.println("RPC initialization fail");
+  }
 
   if (currentCPU() == "M7") {
     // M7 CPU becomes the server, so it makes two functions available under the defined names
     RPC.bind("remoteAdd", addOnM7);
     RPC.bind("remoteSubtract", subtractOnM7);
-  } 
+  }
 
   if (currentCPU() == "M4") {
     // M4 CPU becomes the client, so spawns a thread that will call subtractOnM7() every 700ms
@@ -75,7 +75,7 @@ void setup() {
 void loop() {
 
   if (currentCPU() == "M4") {
-    // On M4 let's blink an LED. While it's blinking, the callSubstractFromM4() thread is running, 
+    // On M4 let's blink an LED. While it's blinking, the callSubstractFromM4() thread is running,
     // so it will execute roughly 3 times (2000 / 700 ms)
     digitalWrite(LED_BUILTIN, LOW);
     delay(1000);
@@ -84,27 +84,26 @@ void loop() {
 
     int a = random(100);
     int b = random(100);
-    // PRC.print works like a Serial port, but it needs a receiver (in this case the M7) 
+    // SerialRPC.print works like a Serial port, but it needs a receiver (in this case the M7)
     // to actually print the strings to the Serial port
-    RPC.println(currentCPU() + ": calling add with " + String(a) + " and " + String(b));
+    SerialRPC.println(currentCPU() + ": calling add with " + String(a) + " and " + String(b));
     // Let's invoke addOnM7() and wait for a result.
     // This will be delayed by the forced delay() in addOnM7() function
     // Exercise: if you are not interested in the result of the operation, what operation would you invoke?
-    auto result = RPC.call("remoteAdd", a, b).as<int>();    
-    RPC.println(currentCPU() + ": Result is " + String(a) + " + " + String(b) + " = " + String(result));
+    auto result = RPC.call("remoteAdd", a, b).as<int>();
+    SerialRPC.println(currentCPU() + ": Result is " + String(a) + " + " + String(b) + " = " + String(result));
   }
-  
+
   if (currentCPU() == "M7") {
-    // On M7, let's print everything that is received over the RPC1 stream interface
+    // On M7, let's print everything that is received over the SerialRPC stream interface
     // Buffer it, otherwise all characters will be interleaved by other prints
     String buffer = "";
-    while (RPC.available()) {
-      buffer += (char)RPC.read(); // Fill the buffer with characters
+    while (SerialRPC.available()) {
+      buffer += (char)SerialRPC.read(); // Fill the buffer with characters
     }
 
     if (buffer.length() > 0) {
       Serial.print(buffer);
     }
   }
-
 }