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ATParser.cpp@6:51f1171b5ebc, 2015-07-17 (annotated)
- Committer:
- geky
- Date:
- Fri Jul 17 21:00:23 2015 +0000
- Revision:
- 6:51f1171b5ebc
- Parent:
- 5:26bc9255b751
- Child:
- 7:d1b193880af1
Exposed raw read/write methods
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
geky | 0:c741e144517c | 1 | /* Copyright (c) 2015 ARM Limited |
geky | 0:c741e144517c | 2 | * |
geky | 0:c741e144517c | 3 | * Licensed under the Apache License, Version 2.0 (the "License"); |
geky | 0:c741e144517c | 4 | * you may not use this file except in compliance with the License. |
geky | 0:c741e144517c | 5 | * You may obtain a copy of the License at |
geky | 0:c741e144517c | 6 | * |
geky | 0:c741e144517c | 7 | * http://www.apache.org/licenses/LICENSE-2.0 |
geky | 0:c741e144517c | 8 | * |
geky | 0:c741e144517c | 9 | * Unless required by applicable law or agreed to in writing, software |
geky | 0:c741e144517c | 10 | * distributed under the License is distributed on an "AS IS" BASIS, |
geky | 0:c741e144517c | 11 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
geky | 0:c741e144517c | 12 | * See the License for the specific language governing permissions and |
geky | 0:c741e144517c | 13 | * limitations under the License. |
geky | 0:c741e144517c | 14 | * |
geky | 0:c741e144517c | 15 | * @section DESCRIPTION |
geky | 0:c741e144517c | 16 | * |
geky | 0:c741e144517c | 17 | * Parser for the AT command syntax |
geky | 0:c741e144517c | 18 | * |
geky | 0:c741e144517c | 19 | */ |
geky | 0:c741e144517c | 20 | |
geky | 0:c741e144517c | 21 | #include "ATParser.h" |
geky | 0:c741e144517c | 22 | |
geky | 0:c741e144517c | 23 | // This can be defined to assist in debugging |
geky | 2:4d68f546861c | 24 | #define AT_ECHO 1 |
geky | 0:c741e144517c | 25 | |
geky | 0:c741e144517c | 26 | |
geky | 0:c741e144517c | 27 | // getc/putc handling with timeouts |
geky | 4:38acbd6f9d9e | 28 | int ATParser::putc(char c) { |
geky | 0:c741e144517c | 29 | Timer timer; |
geky | 0:c741e144517c | 30 | timer.start(); |
geky | 0:c741e144517c | 31 | |
geky | 0:c741e144517c | 32 | while (true) { |
geky | 0:c741e144517c | 33 | if (_serial->writeable()) |
geky | 0:c741e144517c | 34 | return _serial->putc(c); |
geky | 0:c741e144517c | 35 | |
geky | 0:c741e144517c | 36 | if (timer.read_ms() > _timeout) |
geky | 0:c741e144517c | 37 | return -1; |
geky | 0:c741e144517c | 38 | } |
geky | 0:c741e144517c | 39 | } |
geky | 0:c741e144517c | 40 | |
geky | 4:38acbd6f9d9e | 41 | int ATParser::getc() { |
geky | 0:c741e144517c | 42 | Timer timer; |
geky | 0:c741e144517c | 43 | timer.start(); |
geky | 0:c741e144517c | 44 | |
geky | 0:c741e144517c | 45 | while (true) { |
geky | 0:c741e144517c | 46 | if (_serial->readable()) |
geky | 0:c741e144517c | 47 | return _serial->getc(); |
geky | 0:c741e144517c | 48 | |
geky | 0:c741e144517c | 49 | if (timer.read_ms() > _timeout) |
geky | 0:c741e144517c | 50 | return -1; |
geky | 0:c741e144517c | 51 | } |
geky | 0:c741e144517c | 52 | } |
geky | 0:c741e144517c | 53 | |
geky | 4:38acbd6f9d9e | 54 | void ATParser::flush() { |
geky | 0:c741e144517c | 55 | while (_serial->readable()) |
geky | 0:c741e144517c | 56 | _serial->getc(); |
geky | 0:c741e144517c | 57 | } |
geky | 0:c741e144517c | 58 | |
geky | 6:51f1171b5ebc | 59 | // read/write handling with timeouts |
geky | 6:51f1171b5ebc | 60 | int ATParser::write(const char *data, int size) { |
geky | 6:51f1171b5ebc | 61 | int i; |
geky | 6:51f1171b5ebc | 62 | |
geky | 6:51f1171b5ebc | 63 | for (i = 0; i < size; i++) { |
geky | 6:51f1171b5ebc | 64 | if (putc(data[i]) < 0) |
geky | 6:51f1171b5ebc | 65 | return i; |
geky | 6:51f1171b5ebc | 66 | } |
geky | 6:51f1171b5ebc | 67 | |
geky | 6:51f1171b5ebc | 68 | return i; |
geky | 6:51f1171b5ebc | 69 | } |
geky | 6:51f1171b5ebc | 70 | |
geky | 6:51f1171b5ebc | 71 | int ATParser::read(char *data, int size) { |
geky | 6:51f1171b5ebc | 72 | int i; |
geky | 6:51f1171b5ebc | 73 | |
geky | 6:51f1171b5ebc | 74 | for (i = 0; i < size; i++) { |
geky | 6:51f1171b5ebc | 75 | int c = getc(); |
geky | 6:51f1171b5ebc | 76 | |
geky | 6:51f1171b5ebc | 77 | if (c < 0) |
geky | 6:51f1171b5ebc | 78 | return i; |
geky | 6:51f1171b5ebc | 79 | |
geky | 6:51f1171b5ebc | 80 | data[i] = c; |
geky | 6:51f1171b5ebc | 81 | } |
geky | 6:51f1171b5ebc | 82 | |
geky | 6:51f1171b5ebc | 83 | return i; |
geky | 6:51f1171b5ebc | 84 | } |
geky | 6:51f1171b5ebc | 85 | |
geky | 1:66a14afe650a | 86 | |
geky | 0:c741e144517c | 87 | // getline/putline handling with timeouts/bounds checking |
geky | 1:66a14afe650a | 88 | bool ATParser::_putline(const char *line) { |
geky | 0:c741e144517c | 89 | for (int i = 0; line[i]; i++) { |
geky | 4:38acbd6f9d9e | 90 | if (putc(line[i]) < 0) |
geky | 0:c741e144517c | 91 | return false; |
geky | 0:c741e144517c | 92 | } |
geky | 0:c741e144517c | 93 | |
geky | 0:c741e144517c | 94 | // Finish with newline |
geky | 3:32915b9467d2 | 95 | for (int i = 0; _delimiter[i]; i++) { |
geky | 4:38acbd6f9d9e | 96 | if (putc(_delimiter[i]) < 0) |
geky | 3:32915b9467d2 | 97 | return false; |
geky | 3:32915b9467d2 | 98 | } |
geky | 0:c741e144517c | 99 | |
geky | 0:c741e144517c | 100 | #ifdef AT_ECHO |
geky | 0:c741e144517c | 101 | printf("AT> %s\r\n", line); |
geky | 0:c741e144517c | 102 | #endif |
geky | 1:66a14afe650a | 103 | |
geky | 0:c741e144517c | 104 | return true; |
geky | 0:c741e144517c | 105 | } |
geky | 0:c741e144517c | 106 | |
geky | 1:66a14afe650a | 107 | bool ATParser::_getline(char *line, int size) { |
geky | 1:66a14afe650a | 108 | int i = 0; |
geky | 1:66a14afe650a | 109 | |
geky | 1:66a14afe650a | 110 | while (i < size) { |
geky | 4:38acbd6f9d9e | 111 | int c = getc(); |
geky | 1:66a14afe650a | 112 | if (c < 0) |
geky | 1:66a14afe650a | 113 | return false; |
geky | 3:32915b9467d2 | 114 | |
geky | 3:32915b9467d2 | 115 | line[i++] = c; |
geky | 0:c741e144517c | 116 | |
geky | 1:66a14afe650a | 117 | // Finish when we hit a newline |
geky | 3:32915b9467d2 | 118 | if (memcmp(&line[i-_delim_size], _delimiter, _delim_size) == 0) { |
geky | 3:32915b9467d2 | 119 | line[i-_delim_size] = 0; |
geky | 3:32915b9467d2 | 120 | #ifdef AT_ECHO |
geky | 0:c741e144517c | 121 | printf("AT< %s\r\n", line); |
geky | 0:c741e144517c | 122 | #endif |
geky | 0:c741e144517c | 123 | return true; |
geky | 0:c741e144517c | 124 | } |
geky | 0:c741e144517c | 125 | } |
geky | 0:c741e144517c | 126 | |
geky | 0:c741e144517c | 127 | // Ran out of space |
geky | 0:c741e144517c | 128 | return false; |
geky | 1:66a14afe650a | 129 | } |
geky | 0:c741e144517c | 130 | |
geky | 5:26bc9255b751 | 131 | |
geky | 5:26bc9255b751 | 132 | // Command parsing with line handling |
geky | 5:26bc9255b751 | 133 | bool ATParser::vsend(const char *command, va_list args) { |
geky | 4:38acbd6f9d9e | 134 | flush(); |
geky | 0:c741e144517c | 135 | |
geky | 0:c741e144517c | 136 | // Create and send command |
geky | 5:26bc9255b751 | 137 | if (vsprintf(_buffer, command, args) < 0) |
geky | 5:26bc9255b751 | 138 | return false; |
geky | 5:26bc9255b751 | 139 | if (!_putline(_buffer)) |
geky | 5:26bc9255b751 | 140 | return false; |
geky | 5:26bc9255b751 | 141 | |
geky | 5:26bc9255b751 | 142 | return true; |
geky | 5:26bc9255b751 | 143 | } |
geky | 5:26bc9255b751 | 144 | |
geky | 5:26bc9255b751 | 145 | bool ATParser::vrecv(const char *response, va_list args) { |
geky | 1:66a14afe650a | 146 | // Iterate through each line in the expected response |
geky | 5:26bc9255b751 | 147 | while (response[0]) { |
geky | 1:66a14afe650a | 148 | // Since response is const, we need to copy it into our buffer to |
geky | 1:66a14afe650a | 149 | // add the line's null terminator and clobber value matches with asterisks. |
geky | 1:66a14afe650a | 150 | // |
geky | 1:66a14afe650a | 151 | // We just use the beginning of the buffer to avoid unecessary allocations. |
geky | 1:66a14afe650a | 152 | int i = 0; |
geky | 1:66a14afe650a | 153 | int offset = 0; |
geky | 1:66a14afe650a | 154 | |
geky | 1:66a14afe650a | 155 | while (response[i]) { |
geky | 5:26bc9255b751 | 156 | if (memcmp(&response[i+1-_delim_size], _delimiter, _delim_size) == 0) { |
geky | 5:26bc9255b751 | 157 | i++; |
geky | 1:66a14afe650a | 158 | break; |
geky | 1:66a14afe650a | 159 | } else if (response[i] == '%' && |
geky | 1:66a14afe650a | 160 | response[i+1] != '%' && |
geky | 1:66a14afe650a | 161 | response[i+1] != '*') { |
geky | 1:66a14afe650a | 162 | _buffer[offset++] = '%'; |
geky | 1:66a14afe650a | 163 | _buffer[offset++] = '*'; |
geky | 3:32915b9467d2 | 164 | i++; |
geky | 1:66a14afe650a | 165 | } else { |
geky | 1:66a14afe650a | 166 | _buffer[offset++] = response[i++]; |
geky | 1:66a14afe650a | 167 | } |
geky | 1:66a14afe650a | 168 | } |
geky | 1:66a14afe650a | 169 | |
geky | 1:66a14afe650a | 170 | // Scanf has very poor support for catching errors |
geky | 1:66a14afe650a | 171 | // fortunately, we can abuse the %n specifier to determine |
geky | 1:66a14afe650a | 172 | // if the entire string was matched. |
geky | 1:66a14afe650a | 173 | _buffer[offset++] = '%'; |
geky | 1:66a14afe650a | 174 | _buffer[offset++] = 'n'; |
geky | 1:66a14afe650a | 175 | _buffer[offset++] = 0; |
geky | 1:66a14afe650a | 176 | |
geky | 1:66a14afe650a | 177 | // To workaround scanf's lack of error reporting, we actually |
geky | 1:66a14afe650a | 178 | // make two passes. One checks the validity with the modified |
geky | 1:66a14afe650a | 179 | // format string that only stores the matched characters (%n). |
geky | 1:66a14afe650a | 180 | // The other reads in the actual matched values. |
geky | 1:66a14afe650a | 181 | // |
geky | 1:66a14afe650a | 182 | // We keep trying the match until we succeed or some other error |
geky | 1:66a14afe650a | 183 | // derails us. |
geky | 1:66a14afe650a | 184 | while (true) { |
geky | 1:66a14afe650a | 185 | // Recieve response |
geky | 5:26bc9255b751 | 186 | if (!_getline(_buffer+offset, _buffer_size-offset)) |
geky | 1:66a14afe650a | 187 | return false; |
geky | 1:66a14afe650a | 188 | |
geky | 2:4d68f546861c | 189 | int count = -1; |
geky | 1:66a14afe650a | 190 | sscanf(_buffer+offset, _buffer, &count); |
geky | 1:66a14afe650a | 191 | |
geky | 1:66a14afe650a | 192 | // We only succeed if all characters in the response is matched |
geky | 2:4d68f546861c | 193 | if (count >= 0 && (_buffer+offset)[count] == 0) { |
geky | 1:66a14afe650a | 194 | // Reuse the front end of the buffer |
geky | 6:51f1171b5ebc | 195 | memcpy(_buffer, response, i); |
geky | 6:51f1171b5ebc | 196 | _buffer[i] = 0; |
geky | 1:66a14afe650a | 197 | |
geky | 1:66a14afe650a | 198 | // Store the found results |
geky | 1:66a14afe650a | 199 | vsscanf(_buffer+offset, _buffer, args); |
geky | 1:66a14afe650a | 200 | |
geky | 1:66a14afe650a | 201 | // Jump to next line and continue parsing |
geky | 1:66a14afe650a | 202 | response += i; |
geky | 1:66a14afe650a | 203 | break; |
geky | 1:66a14afe650a | 204 | } |
geky | 1:66a14afe650a | 205 | } |
geky | 0:c741e144517c | 206 | } |
geky | 5:26bc9255b751 | 207 | |
geky | 5:26bc9255b751 | 208 | return true; |
geky | 5:26bc9255b751 | 209 | } |
geky | 5:26bc9255b751 | 210 | |
geky | 5:26bc9255b751 | 211 | bool ATParser::vcommand(const char *command, const char *response, va_list args) { |
geky | 5:26bc9255b751 | 212 | if (command) { |
geky | 5:26bc9255b751 | 213 | if (!vsend(command, args)) |
geky | 5:26bc9255b751 | 214 | return false; |
geky | 5:26bc9255b751 | 215 | } |
geky | 5:26bc9255b751 | 216 | |
geky | 5:26bc9255b751 | 217 | if (response) { |
geky | 5:26bc9255b751 | 218 | if (!vrecv(response, args)) |
geky | 5:26bc9255b751 | 219 | return false; |
geky | 5:26bc9255b751 | 220 | } |
geky | 5:26bc9255b751 | 221 | |
geky | 0:c741e144517c | 222 | return true; |
geky | 0:c741e144517c | 223 | } |
geky | 5:26bc9255b751 | 224 | |
geky | 5:26bc9255b751 | 225 | // Mapping to vararg functions |
geky | 5:26bc9255b751 | 226 | bool ATParser::send(const char *command, ...) { |
geky | 5:26bc9255b751 | 227 | va_list args; |
geky | 5:26bc9255b751 | 228 | va_start(args, command); |
geky | 5:26bc9255b751 | 229 | bool res = vsend(command, args); |
geky | 5:26bc9255b751 | 230 | va_end(args); |
geky | 5:26bc9255b751 | 231 | return res; |
geky | 5:26bc9255b751 | 232 | } |
geky | 5:26bc9255b751 | 233 | |
geky | 5:26bc9255b751 | 234 | bool ATParser::recv(const char *response, ...) { |
geky | 5:26bc9255b751 | 235 | va_list args; |
geky | 5:26bc9255b751 | 236 | va_start(args, response); |
geky | 5:26bc9255b751 | 237 | bool res = vrecv(response, args); |
geky | 5:26bc9255b751 | 238 | va_end(args); |
geky | 5:26bc9255b751 | 239 | return res; |
geky | 5:26bc9255b751 | 240 | } |
geky | 5:26bc9255b751 | 241 | |
geky | 5:26bc9255b751 | 242 | bool ATParser::command(const char *command, const char *response, ...) { |
geky | 5:26bc9255b751 | 243 | va_list args; |
geky | 5:26bc9255b751 | 244 | va_start(args, response); |
geky | 5:26bc9255b751 | 245 | bool res = vcommand(command, response, args); |
geky | 5:26bc9255b751 | 246 | va_end(args); |
geky | 5:26bc9255b751 | 247 | return res; |
geky | 5:26bc9255b751 | 248 | } |