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Diffstat (limited to 'libraries/Bridge/Bridge.cpp')
| -rw-r--r-- | libraries/Bridge/Bridge.cpp | 207 |
1 files changed, 207 insertions, 0 deletions
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 |