libraries/RPC: Update examples.

Signed-off-by: iabdalkader <i.abdalkader@gmail.com>

Author: iabdalkader

libraries/RPC/examples/Basic_AddSub/Basic_AddSub.ino

@@ -4,22 +4,46 @@ int add(int a, int b) {
   return a + b;
 }
 
-void setup() {  
+int sub(int a, int b) {
+  return a - b;
+}
+
+void setup() {
+  Serial.begin(115200);
+  while (!Serial) {
+
+  }
+
   RPC.begin();
   RPC.bind("add", add);
+  RPC.bind("sub", sub);
+  if (HAL_GetCurrentCPUID() == CM7_CPUID) {
+    // Introduce a brief delay to allow the M4 sufficient time
+    // to bind remote functions before invoking them.
+    delay(100);
+  }
   pinMode(LEDG, OUTPUT);
 }
 
 void loop() {
   static size_t loop_count = 0;
+
   // Blink every 512 iterations
-  if ((loop_count++ % 512) == 0) {
+  if (HAL_GetCurrentCPUID() == CM4_CPUID && (loop_count++ % 512) == 0) {
     digitalWrite(LEDG, LOW);
     delay(10);
     digitalWrite(LEDG, HIGH);
     delay(10);
   }
+
   int res = RPC.call("add", 1, 2).as<int>();
-  RPC.call("sub", res, 1).as<int>();
+  if (HAL_GetCurrentCPUID() == CM7_CPUID) {
+    Serial.println("add(1, 2) = " + String(res));
+  }
+
+  res = RPC.call("sub", res, 1).as<int>();
+  if (HAL_GetCurrentCPUID() == CM7_CPUID) {
+    Serial.println("sub(3, 1) = " + String(res));
+  }
   delay(250);
 }

libraries/RPC/examples/MD5_Checksum/MD5_Checksum.ino

@@ -7,7 +7,7 @@ size_t hash_out_count = 0;
 #ifdef CORE_CM4
 size_t data_buf_size = 0;
 #else
-size_t data_buf_size = 512;
+size_t data_buf_size = 256;
 #endif
 
 typedef std::vector<byte> vec_t;
@@ -59,6 +59,8 @@ void setup() {
     #ifdef CORE_CM4
     RPC.bind("set_buffer_size", set_buffer_size);    
     #else
+    // Introduce a brief delay to allow the M4 sufficient time
+    // to bind remote functions before invoking them.
     delay(100);
     auto ret = RPC.call("set_buffer_size", data_buf_size).as<size_t>();
     #endif