Parser for AT commands and similar protocols
Dependencies: BufferedSerial
Dependents: ESP8266 Final_Project_2 Final_Project CHEN_Final_Project
ATParser.cpp
- Committer:
- geky
- Date:
- 2015-07-15
- Revision:
- 0:c741e144517c
- Child:
- 1:66a14afe650a
File content as of revision 0:c741e144517c:
/* Copyright (c) 2015 ARM Limited * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * @section DESCRIPTION * * Parser for the AT command syntax * */ #include "ATParser.h" #include <cstdarg> // This can be defined to assist in debugging #define AT_ECHO 1 // getc/putc handling with timeouts int ATParser::_putc(char c) { Timer timer; timer.start(); while (true) { if (_serial->writeable()) return _serial->putc(c); if (timer.read_ms() > _timeout) return -1; } } int ATParser::_getc() { Timer timer; timer.start(); while (true) { if (_serial->readable()) return _serial->getc(); if (timer.read_ms() > _timeout) return -1; } } void ATParser::_flush() { while (_serial->readable()) _serial->getc(); } // getline/putline handling with timeouts/bounds checking bool ATParser::_putline(const char *line) { for (int i = 0; line[i]; i++) { if (_putc(line[i]) < 0) return false; } // Finish with newline if (_putc('\r') < 0 || _putc('\n') < 0) return false; #ifdef AT_ECHO printf("AT> %s\r\n", line); #endif return true; } bool ATParser::_getline(int size, char *line) { for (int i = 0; i < size; i++) { int c = _getc(); if (c < 0) return false; // Finish if newline if (c == '\r') { if (_getc() != '\n') return false; line[i] = 0; #ifdef AT_ECHO printf("AT< %s\r\n", line); #endif return true; } line[i] = c; } // Ran out of space return false; } bool ATParser::command(const char *command, const char *response, ...) { va_list args; va_start(args, response); _flush(); // Create and send command if (vsprintf(_buffer, command, args) < 0 || !_putline(_buffer)) { va_end(args); return false; } // Determine number of parameters // this is needed for scanf's funky error signaling int params = 0; for (int i = 0; response[i]; i++) { if (response[i] == '%' && response[i+1] != '%') params++; } // Recieve and parse response if (!_getline(_buffer_size, _buffer) || vsscanf(_buffer, response, args) < params) { va_end(args); return false; } va_end(args); return true; }