Adding basic chat system project to the hackerling circuit.

software/libraries/Chat_System/chat_system.cpp

@@ -0,0 +1,96 @@
+#include "chat_system.h"
+
+LCD lcd;
+IR_COM ir_com;
+
+User::User(HardwareSerial* printer)
+  : printer_(printer) {}
+
+void User::ShowMessage(String text) {
+  Serial.println(text);
+  if (text.length() > 16) {
+    text = text.substring(0, 14) + "..";
+  }
+  lcd.clear();
+  lcd.setCursor(0,0);
+  lcd.print(previous_line_);
+  lcd.setCursor(0,1);
+  lcd.print(text);
+  previous_line_ = text;
+}
+
+void User::Init() {
+  Serial.begin(9600);
+  lcd.begin(16,2);
+  // Useful?
+  hs.begin();
+}
+
+bool User::HasMessageToSend() {
+  if (available_) {
+    return true;
+  }
+  while (Serial.available() > 0) {
+    char c = Serial.read();
+    if (c == '\n') {
+      available_ = true;
+      return true;
+    } else {
+      current_reading_line_ += c;
+    }
+  }
+  return false;
+}
+
+String User::GetMessageToSend() {
+  String result;
+  if (available_) {
+    result = current_reading_line_;
+    current_reading_line_ = "";
+    available_ = false;
+  }
+  return result;
+}
+
+void IRInterface::Init() {
+  ir_com.begin();
+}
+
+void IRInterface::Send(const Message& message) {
+  String text = message.name + ":" + message.text;
+  for (int i = 0; i < text.length(); ++i) {
+    ir_com.write(text[i]);
+  }
+  ir_com.write('\0');
+}
+
+bool IRInterface::ReceivedMessage() {
+  if (available_) {
+    return true;
+  }
+  while (ir_com.available() > 0) {
+    char c = ir_com.read();
+    if (c == '\0') {
+      available_ = true;
+      return true;
+    } else {
+      current_message_ += c;
+    }
+  }
+  return false;
+}
+
+Message IRInterface::GetReceivedMessage() {
+   Message result;
+   if (available_) {
+     int i = 0;
+     while (i < current_message_.length() && current_message_[i] != ':') {
+       result.name += current_message_[i];
+       ++i;
+     }
+     result.text = current_message_.substring(i + 1, current_message_.length());
+     current_message_ = "";
+     available_ = false;
+   }
+   return result;
+}

software/libraries/Chat_System/chat_system.h

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+#ifndef __CHAT_SYSTEM_HACKERLNG_SHIELD_H__
+#define __CHAT_SYSTEM_HACKERLNG_SHIELD_H__
+
+#include <IR_COM.h>
+#include <Wire.h>
+#include <MCP23017.h>
+#include <Hackerling_Shield.h>
+#include <HardwareSerial.h>
+#include <MCP23008.h>
+#include <LCD.h>
+
+// Represents the user of the arduino. Allows to read the messages he wrote and
+// show him messages on the computer screen.
+// Uses the Serial to communicate with the user.
+class User {
+ public:
+  // Creates an user object.
+  // params:
+  //  * printer: pointer to the arduino Serial.
+  User(HardwareSerial* printer);
+
+  // Initializes the user. Need to be call before calling any other function.
+  void Init();
+
+  // Shows a message to the user screen.
+  void ShowMessage(String text);
+
+  // Returns yes if the user wrote a message that is waiting to be sent.
+  bool HasMessageToSend();
+
+  // Get the message the user wrote.
+  String GetMessageToSend();
+
+ private:
+  String current_reading_line_;
+  bool available_;
+  String previous_line_;
+  HardwareSerial* printer_;
+};
+
+struct Message {
+  String name;
+  String text;
+};
+
+// Allows to communicate with other shields though infra red.
+class IRInterface {
+ public:
+  // Initializes the IR interface. Has to be called before any other function
+  // call.
+  void Init();
+
+  // Returns true if a message from another user has been received.
+  bool ReceivedMessage();
+
+  // Get the message that has been received from another user.
+  Message GetReceivedMessage();
+
+  // Send a message to other users by infra red.
+  void Send(const Message& message);
+
+ private:
+  String current_message_;
+  bool available_;
+};
+
+#endif  // __CHAT_SYSTEM_HACKERLNG_SHIELD_H__

software/projects/chat_system/chat_system.ino

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+#include <IR_COM.h>
+#include <Wire.h>
+#include <MCP23017.h>
+#include <Hackerling_Shield.h>
+#include <HardwareSerial.h>
+#include <MCP23008.h>
+#include <LCD.h>
+
+#include <chat_system.h>
+
+User user(&Serial);
+IRInterface ir_interface;
+String my_name;
+
+void setup() {
+  // Initialises the user and IR interface.
+  ir_interface.Init();
+  user.Init();
+  // Initializes username.
+  my_name = "Adrien";
+  // Show a welcome message to the user.
+  user.ShowMessage("Welcome to the");
+  user.ShowMessage("chat system");
+}
+
+void loop() {
+  if (ir_interface.ReceivedMessage()) {
+    Message message = ir_interface.GetReceivedMessage();
+    user.ShowMessage(message.name + ": " + message.text);
+    // Optional improvement.
+    // Add forwarding of message to allow more than 2 users to join the chat.
+  }
+
+  if (user.HasMessageToSend()) {
+    String line = user.GetMessageToSend();
+    // Show to the user his own message.
+    user.ShowMessage("you: " + line);
+    // Initializes a message and send it.
+    Message message;
+    message.name = my_name;
+    message.text = line;
+    ir_interface.Send(message);
+  }
+}