From f12d265653719924d59c774312ff506dc16ea261 Mon Sep 17 00:00:00 2001
From: Federico Fissore <f.fissore@arduino.cc>
Date: Thu, 9 May 2013 11:14:59 +0200
Subject: Bridge lib moved bridge branch embedded into ide discovery branch

---
 libraries/Bridge/Bridge.cpp | 207 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 207 insertions(+)
 create mode 100644 libraries/Bridge/Bridge.cpp

(limited to 'libraries/Bridge/Bridge.cpp')

diff --git a/libraries/Bridge/Bridge.cpp b/libraries/Bridge/Bridge.cpp
new file mode 100644
index 0000000..b91814b
--- /dev/null
+++ b/libraries/Bridge/Bridge.cpp
@@ -0,0 +1,207 @@
+/*
+  Copyright (c) 2013 Arduino LLC. All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+*/
+
+#include "Bridge.h"
+
+void BridgeClass::begin() {
+  if (started)
+    return;
+  started = true;
+  
+  // TODO: A more robust restart
+  // Bridge startup:
+  // - If the bridge is not running starts it safely
+  print(CTRL_C);
+  print(F("\n"));
+  delay(500);
+  // Wait for OpenWRT message
+  // "Press enter to activate console"
+  print(F("\ncd /root\n"));
+  delay(100);
+  print(F("python bridge.py\n"));
+  delay(1000);
+  dropAll();
+  
+  // - If the bridge was already running previous commands
+  //   are ignored as "invalid packets".
+  
+  // Reset the brigde
+  uint8_t cmd[] = {'X','X'};
+  transfer(cmd, 2);
+}
+
+uint8_t BridgeClass::runCommand(String &command) {
+  // TODO: do it in a more efficient way
+  String cmd = "R" + command;
+  uint8_t res[1];
+  transfer((uint8_t*)cmd.c_str(), cmd.length(), res, 1);
+  return res[0];
+}
+
+bool BridgeClass::commandIsRunning(uint8_t handle) {
+  uint8_t cmd[] = {'r', handle};
+  uint8_t res[1];
+  transfer(cmd, 2, res, 1);
+  return (res[0] == 1);
+}
+
+unsigned int BridgeClass::commandExitValue(uint8_t handle) {
+  uint8_t cmd[] = {'W', handle};
+  uint8_t res[2];
+  transfer(cmd, 2, res, 2);
+  return (res[0] << 8) + res[1];
+}
+
+void BridgeClass::cleanCommand(uint8_t handle) {
+  uint8_t cmd[] = {'w', handle};
+  transfer(cmd, 2);
+}
+
+unsigned int BridgeClass::commandOutputAvailable(uint8_t handle) {
+  uint8_t cmd[] = {'o', handle};
+  uint8_t res[1];
+  transfer(cmd, 2, res, 1);
+  return res[0];
+}
+
+unsigned int BridgeClass::readCommandOutput(uint8_t handle, 
+                                            uint8_t *buffer, unsigned int size) {
+  if (size > 255)
+    size = 255;
+  uint8_t cmd[] = {'O', handle, size};
+  return transfer(cmd, 3, buffer, size);
+}
+
+void BridgeClass::writeCommandInput(uint8_t handle, 
+                                    uint8_t *buff, unsigned int size) {
+  // TODO: do it in a more efficient way
+  uint8_t *tmp = new uint8_t[size+2];
+  tmp[0] = 'I';
+  tmp[1] = handle;
+  memcpy(tmp+2, buff, size);
+  transfer(tmp, size+2);
+  delete[] tmp;
+}
+
+void BridgeClass::crcUpdate(uint8_t c) {
+  CRC = CRC ^ c;
+  CRC = (CRC >> 8) + (CRC << 8);
+}
+
+void BridgeClass::crcReset() {
+  CRC = 0xAAAA;
+}
+
+void BridgeClass::crcWrite() {
+  write((char)(CRC >> 8));
+  write((char)(CRC & 0xFF));
+}
+
+bool BridgeClass::crcCheck(uint16_t _CRC) {
+  return CRC == _CRC;
+}
+
+uint8_t BridgeClass::transfer(uint8_t *buff, uint8_t len, 
+                              uint8_t *rxbuff, uint8_t rxlen) 
+{
+  for ( ; ; delay(100), dropAll() /* Delay for retransmission */) {
+    // Send packet
+    crcReset();
+    write((char)0xFF);              // Start of packet (0xFF)
+    crcUpdate(0xFF);
+    write((char)index);             // Message index
+    crcUpdate(index);
+    write((char)len);               // Message length
+    crcUpdate(len);
+    for (uint8_t i=0; i<len; i++) { // Payload
+      write((char)buff[i]);
+      crcUpdate(buff[i]);
+    }
+    crcWrite();                     // CRC
+  
+    // Wait for ACK in 100ms
+    if (timedRead(100) != 0xFF)
+      continue;
+    crcReset();
+    crcUpdate(0xFF);
+    
+    // Check packet index
+    if (timedRead(5) != index)
+      continue;
+    crcUpdate(index);
+    
+    // Recv len
+    uint8_t l = timedRead(5);
+    if (l < 0)
+      continue;
+    crcUpdate(l);
+
+    // Recv data
+    for (uint8_t i=0; i<l; i++) {
+      int c = timedRead(5);
+      if (c < 0)
+        continue;
+      // Cut received data if rxbuffer is too small
+      if (i < rxlen)
+        rxbuff[i] = c;
+      crcUpdate(c);
+    }
+    
+    // Check CRC
+    int crc_hi = timedRead(5);
+    if (crc_hi < 0)
+      continue;
+    int crc_lo = timedRead(5);
+    if (crc_lo < 0)
+      continue;
+    if (!crcCheck((crc_hi<<8)+crc_lo))
+      continue;
+    
+    // Increase index
+    index++;
+    
+    // Return bytes received
+    if (l > rxlen)
+      return rxlen;
+    return l;
+  }
+}
+
+int BridgeClass::timedRead(unsigned int timeout) {
+  int c;
+  unsigned long _startMillis = millis();
+  do {
+    c = read();
+    if (c >= 0) return c;
+  } while(millis() - _startMillis < timeout);
+  return -1;     // -1 indicates timeout
+}
+
+void BridgeClass::dropAll() {
+  while (available() > 0) {
+    read();
+  }
+}
+
+// Bridge instance
+#ifdef __AVR_ATmega32U4__
+  // Leonardo variants (where HardwareSerial is Serial1)
+  SerialBridgeClass Bridge(Serial1);
+#else
+  SerialBridgeClass Bridge(Serial);
+#endif
-- 
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