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Diffstat (limited to 'libraries/Bridge/Bridge.cpp')
| -rw-r--r-- | libraries/Bridge/Bridge.cpp | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/libraries/Bridge/Bridge.cpp b/libraries/Bridge/Bridge.cpp new file mode 100644 index 0000000..a3d911f --- /dev/null +++ b/libraries/Bridge/Bridge.cpp @@ -0,0 +1,229 @@ +/* + 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" +#include <util/crc16.h> + +BridgeClass::BridgeClass(Stream &_stream) : + index(0), stream(_stream), started(false), max_retries(0) { + // Empty +} + +void BridgeClass::begin() { + if (started) + return; + started = true; + + // Wait for U-boot to finish startup + do { + dropAll(); + delay(1000); + } while (stream.available()>0); + + while (true) { + // Bridge interrupt: + // - Ask the bridge to close itself + uint8_t quit_cmd[] = {'X','X','X','X','X'}; + max_retries = 1; + transfer(quit_cmd, 5); + + // Bridge startup: + // - If the bridge is not running starts it safely + stream.print(CTRL_C); + delay(250); + stream.print(F("\n")); + delay(250); + stream.print(F("\n")); + delay(500); + // Wait for OpenWRT message + // "Press enter to activate console" + stream.print(F("run-bridge\n")); + delay(500); + dropAll(); + + // Reset the brigde to check if it is running + uint8_t cmd[] = {'X','X', '1','0','0'}; + uint8_t res[1]; + max_retries = 50; + uint16_t l = transfer(cmd, 5, res, 1); + if (l == TRANSFER_TIMEOUT) { + // Bridge didn't start... + // Maybe the board is starting-up? + + // Wait and retry + delay(1000); + continue; + } + if (res[0] != 0) + while (true); + + max_retries = 50; + return; + } +} + +void BridgeClass::put(const char *key, const char *value) { + // TODO: do it in a more efficient way + String cmd = "D"; + cmd += key; + cmd += "\xFE"; + cmd += value; + transfer((uint8_t*)cmd.c_str(), cmd.length()); +} + +unsigned int BridgeClass::get(const char *key, uint8_t *value, unsigned int maxlen) { + uint8_t cmd[] = {'d'}; + unsigned int l = transfer(cmd, 1, (uint8_t *)key, strlen(key), value, maxlen); + if (l < maxlen) + value[l] = 0; // Zero-terminate string + return l; +} + +void BridgeClass::crcUpdate(uint8_t c) { + + CRC = _crc_ccitt_update(CRC, c); + //CRC = CRC ^ c; + //CRC = (CRC >> 8) + (CRC << 8); +} + +void BridgeClass::crcReset() { + CRC = 0xFFFF; +} + +void BridgeClass::crcWrite() { + stream.write((char)(CRC >> 8)); + stream.write((char)(CRC & 0xFF)); +} + +bool BridgeClass::crcCheck(uint16_t _CRC) { + return CRC == _CRC; +} + +uint16_t BridgeClass::transfer(const uint8_t *buff1, uint16_t len1, + const uint8_t *buff2, uint16_t len2, + const uint8_t *buff3, uint16_t len3, + uint8_t *rxbuff, uint16_t rxlen) +{ + uint16_t len = len1 + len2 + len3; + uint8_t retries = 0; + for ( ; retries<max_retries; retries++, delay(100), dropAll() /* Delay for retransmission */) { + // Send packet + crcReset(); + stream.write((char)0xFF); // Start of packet (0xFF) + crcUpdate(0xFF); + stream.write((char)index); // Message index + crcUpdate(index); + stream.write((char)((len >> 8) & 0xFF)); // Message length (hi) + crcUpdate((len >> 8) & 0xFF); + stream.write((char)(len & 0xFF)); // Message length (lo) + crcUpdate(len & 0xFF); + for (uint16_t i=0; i<len1; i++) { // Payload + stream.write((char)buff1[i]); + crcUpdate(buff1[i]); + } + for (uint16_t i=0; i<len2; i++) { // Payload + stream.write((char)buff2[i]); + crcUpdate(buff2[i]); + } + for (uint16_t i=0; i<len3; i++) { // Payload + stream.write((char)buff3[i]); + crcUpdate(buff3[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 + int lh = timedRead(5); + if (lh < 0) + continue; + crcUpdate(lh); + int ll = timedRead(5); + if (ll < 0) + continue; + crcUpdate(ll); + uint16_t l = lh; + l <<= 8; + l += ll; + + // Recv data + for (uint16_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; + } + + // Max retries exceeded + return TRANSFER_TIMEOUT; +} + +int BridgeClass::timedRead(unsigned int timeout) { + int c; + unsigned long _startMillis = millis(); + do { + c = stream.read(); + if (c >= 0) return c; + } while(millis() - _startMillis < timeout); + return -1; // -1 indicates timeout +} + +void BridgeClass::dropAll() { + while (stream.available() > 0) { + stream.read(); + } +} + +// Bridge instance +#ifdef __AVR_ATmega32U4__ + // Leonardo variants (where HardwareSerial is Serial1) + SerialBridgeClass Bridge(Serial1); +#else + SerialBridgeClass Bridge(Serial); +#endif |