From e15a7e1267a6f733d734c5d3b59f3acc28bb4b29 Mon Sep 17 00:00:00 2001
From: Jakob Odersky <jodersky@gmail.com>
Date: Mon, 25 Feb 2013 19:39:53 +0100
Subject: initial commit

---
 arduino/ace_cpp_old/Framer.cpp | 101 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 arduino/ace_cpp_old/Framer.cpp

(limited to 'arduino/ace_cpp_old/Framer.cpp')

diff --git a/arduino/ace_cpp_old/Framer.cpp b/arduino/ace_cpp_old/Framer.cpp
new file mode 100644
index 0000000..03335af
--- /dev/null
+++ b/arduino/ace_cpp_old/Framer.cpp
@@ -0,0 +1,101 @@
+#include "Framer.h"
+
+Framer::Framer():
+  state(WAITING),
+  position(-1),
+  checksum(0) {
+}
+
+void Framer::reset() {
+  position = -1;
+  checksum = 0x00;
+}
+
+void Framer::accept(uint8_t byte) {
+  
+  //if a new byte would cause an overflow, restart frame
+  //note that this should not happen if both communicating parties have defined the same maximum frame length
+  if (position >= MAX_FRAME_SIZE) {
+    reset();
+    return;
+  }
+  
+  if (position != -1) { // i.e. a previous byte exists
+    frameBuffer[position] = staged; 
+    checksum = checksum ^ staged;
+  }
+  
+  position += 1;
+  staged = byte;
+  
+}
+
+void Framer::put(uint8_t byte) {
+  
+  switch(state) {
+    case ESCAPING:
+      accept(byte);
+      state = RECEIVING;
+      break;
+      
+    case WAITING:
+      if (byte == START) {
+        reset();
+        state = RECEIVING;
+      }
+      break;
+      
+    case RECEIVING:
+      switch(byte) {
+        case ESCAPE:
+          state = ESCAPING;
+          break;
+        case START:
+          reset();
+          break;
+        case STOP:
+          state = WAITING;
+          if (staged == checksum) { //at this point, staged byte is the checksum sent in the frame (last byte of frame)
+            onFrame(position, frameBuffer);
+          }
+          break;
+          
+        default:
+          accept(byte);
+          break;
+      }
+  }
+}
+
+  
+
+void Framer::send(uint16_t length, const uint8_t * const data) {
+  uint8_t checksum = 0x00;
+  uint8_t byte;
+  
+  onSendByte(START);
+  for (int i = 0; i < length; ++i) {
+    byte = data[i];
+    if (isCommandByte(byte))
+      onSendByte(ESCAPE);
+      checksum = checksum ^ byte;
+      isCommandByte(byte);
+  }
+  if (isCommandByte(checksum)) {
+    onSendByte(ESCAPE);
+  }
+  onSendByte(checksum);
+  onSendByte(STOP);
+};
+
+
+ //~ cli();
+  //~ TCCR1A = 0; // set entire TCCR1A register to 0
+  //~ TCCR1B = 0; // same for TCCR1B
+  //~ // turn on CTC mode:
+  //~ TCCR1B |= (1 << WGM12);
+  //~ // set CS31 for 64 prescaler
+  //~ TCCR1B |= (1 << CS11);
+  //~ // set compare match register to desired timer count:
+  //~ OCR1A = F_CPU / 1000 / 64; // should be 250 for F_CPU=16Mhz and f = 1000Hz
+  //~ sei();
-- 
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