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1 | /* | |
2 | * This file is part of the libserialport project. | |
3 | * | |
4 | * Copyright (C) 2013 Martin Ling <martin-libserialport@earth.li> | |
5 | * | |
6 | * This program is free software: you can redistribute it and/or modify | |
7 | * it under the terms of the GNU Lesser General Public License as | |
8 | * published by the Free Software Foundation, either version 3 of the | |
9 | * License, or (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU Lesser General Public License | |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | ||
20 | /** | |
21 | * | |
22 | * @mainpage libserialport API | |
23 | * | |
24 | * Introduction | |
25 | * ============ | |
26 | * | |
27 | * libserialport is a minimal library written in C that is intended to take | |
28 | * care of the OS-specific details when writing software that uses serial ports. | |
29 | * | |
30 | * By writing your serial code to use libserialport, you enable it to work | |
31 | * transparently on any platform supported by the library. | |
32 | * | |
33 | * The operations that are supported are: | |
34 | * | |
35 | * - @ref Enumeration (obtaining a list of serial ports on the system) | |
36 | * - @ref Ports | |
37 | * - @ref Configuration (baud rate, parity, etc.) | |
38 | * - @ref Data | |
39 | * - @ref Errors | |
40 | * | |
41 | * libserialport is an open source project released under the LGPL3+ license. | |
42 | * | |
43 | * API principles | |
44 | * ============== | |
45 | * | |
46 | * The API is simple, and designed to be a minimal wrapper around the serial | |
47 | * port support in each OS. | |
48 | * | |
49 | * Most functions take a pointer to a struct sp_port, which represents a serial | |
50 | * port. These structures are always allocated and freed by the library, using | |
51 | * the functions in the @ref Enumeration "Enumeration" section. | |
52 | * | |
53 | * All functions can return only three possible error values. @ref SP_ERR_ARG | |
54 | * indicates the function was called with invalid arguments. @ref SP_ERR_FAIL | |
55 | * indicates that the OS reported a failure. @ref SP_ERR_MEM indicates that a | |
56 | * memory allocation failed. All of these error values are negative. | |
57 | * | |
58 | * When @ref SP_ERR_FAIL is returned, an error code or string description of | |
59 | * the error can be obtained by calling sp_last_error_code() or | |
60 | * sp_last_error_message(). The error code or message is that provided by the | |
61 | * OS; libserialport does not define any error codes or messages of its own. | |
62 | * | |
63 | * Function calls that succeed return @ref SP_OK, which is equal to zero, | |
64 | * or where otherwise documented a positive value. | |
65 | */ | |
66 | ||
67 | #ifndef LIBSERIALPORT_H | |
68 | #define LIBSERIALPORT_H | |
69 | ||
70 | #ifdef __cplusplus | |
71 | extern "C" { | |
72 | #endif | |
73 | ||
74 | #include <stddef.h> | |
75 | #ifdef _WIN32 | |
76 | #include <windows.h> | |
77 | #endif | |
78 | ||
79 | /* Package version macros (e.g. for conditional compilation). */ | |
80 | #define SP_PACKAGE_VERSION_MAJOR @SP_PACKAGE_VERSION_MAJOR@ | |
81 | #define SP_PACKAGE_VERSION_MINOR @SP_PACKAGE_VERSION_MINOR@ | |
82 | #define SP_PACKAGE_VERSION_STRING "@SP_PACKAGE_VERSION@" | |
83 | ||
84 | /* Library/libtool version macros (e.g. for conditional compilation). */ | |
85 | #define SP_LIB_VERSION_CURRENT @SP_LIB_VERSION_CURRENT@ | |
86 | #define SP_LIB_VERSION_REVISION @SP_LIB_VERSION_REVISION@ | |
87 | #define SP_LIB_VERSION_AGE @SP_LIB_VERSION_AGE@ | |
88 | #define SP_LIB_VERSION_STRING "@SP_LIB_VERSION@" | |
89 | ||
90 | /** Return values. */ | |
91 | enum sp_return { | |
92 | /** Operation completed successfully. */ | |
93 | SP_OK = 0, | |
94 | /** Invalid arguments were passed to the function. */ | |
95 | SP_ERR_ARG = -1, | |
96 | /** A system error occured while executing the operation. */ | |
97 | SP_ERR_FAIL = -2, | |
98 | /** A memory allocation failed while executing the operation. */ | |
99 | SP_ERR_MEM = -3, | |
100 | }; | |
101 | ||
102 | /** Port access modes. */ | |
103 | enum sp_mode { | |
104 | /** Open port for read access. */ | |
105 | SP_MODE_READ = 1, | |
106 | /** Open port for write access. */ | |
107 | SP_MODE_WRITE = 2, | |
108 | /** Open port in non-blocking mode. */ | |
109 | SP_MODE_NONBLOCK = 4, | |
110 | }; | |
111 | ||
112 | /** Buffer selection. */ | |
113 | enum sp_buffer { | |
114 | /** Input buffer. */ | |
115 | SP_BUF_INPUT = 1, | |
116 | /** Output buffer. */ | |
117 | SP_BUF_OUTPUT = 2, | |
118 | /** Both buffers. */ | |
119 | SP_BUF_BOTH = 3, | |
120 | }; | |
121 | ||
122 | /** Parity settings. */ | |
123 | enum sp_parity { | |
124 | /** Special value to indicate setting should be left alone. */ | |
125 | SP_PARITY_INVALID = -1, | |
126 | /** No parity. */ | |
127 | SP_PARITY_NONE = 0, | |
128 | /** Odd parity. */ | |
129 | SP_PARITY_ODD = 1, | |
130 | /** Even parity. */ | |
131 | SP_PARITY_EVEN = 2, | |
132 | }; | |
133 | ||
134 | /** RTS pin behaviour. */ | |
135 | enum sp_rts { | |
136 | /** Special value to indicate setting should be left alone. */ | |
137 | SP_RTS_INVALID = -1, | |
138 | /** RTS off. */ | |
139 | SP_RTS_OFF = 0, | |
140 | /** RTS on. */ | |
141 | SP_RTS_ON = 1, | |
142 | /** RTS used for flow control. */ | |
143 | SP_RTS_FLOW_CONTROL = 2, | |
144 | }; | |
145 | ||
146 | /** CTS pin behaviour. */ | |
147 | enum sp_cts { | |
148 | /** Special value to indicate setting should be left alone. */ | |
149 | SP_CTS_INVALID = -1, | |
150 | /** CTS ignored. */ | |
151 | SP_CTS_IGNORE = 0, | |
152 | /** CTS used for flow control. */ | |
153 | SP_CTS_FLOW_CONTROL = 1, | |
154 | }; | |
155 | ||
156 | /** DTR pin behaviour. */ | |
157 | enum sp_dtr { | |
158 | /** Special value to indicate setting should be left alone. */ | |
159 | SP_DTR_INVALID = -1, | |
160 | /** DTR off. */ | |
161 | SP_DTR_OFF = 0, | |
162 | /** DTR on. */ | |
163 | SP_DTR_ON = 1, | |
164 | /** DTR used for flow control. */ | |
165 | SP_DTR_FLOW_CONTROL = 2, | |
166 | }; | |
167 | ||
168 | /** DSR pin behaviour. */ | |
169 | enum sp_dsr { | |
170 | /** Special value to indicate setting should be left alone. */ | |
171 | SP_DSR_INVALID = -1, | |
172 | /** DSR ignored. */ | |
173 | SP_DSR_IGNORE = 0, | |
174 | /** DSR used for flow control. */ | |
175 | SP_DSR_FLOW_CONTROL = 1, | |
176 | }; | |
177 | ||
178 | /** XON/XOFF flow control behaviour. */ | |
179 | enum sp_xonxoff { | |
180 | /** Special value to indicate setting should be left alone. */ | |
181 | SP_XONXOFF_INVALID = -1, | |
182 | /** XON/XOFF disabled. */ | |
183 | SP_XONXOFF_DISABLED = 0, | |
184 | /** XON/XOFF enabled for input only. */ | |
185 | SP_XONXOFF_IN = 1, | |
186 | /** XON/XOFF enabled for output only. */ | |
187 | SP_XONXOFF_OUT = 2, | |
188 | /** XON/XOFF enabled for input and output. */ | |
189 | SP_XONXOFF_INOUT = 3, | |
190 | }; | |
191 | ||
192 | /** Standard flow control combinations. */ | |
193 | enum sp_flowcontrol { | |
194 | /** No flow control. */ | |
195 | SP_FLOWCONTROL_NONE = 0, | |
196 | /** Software flow control using XON/XOFF characters. */ | |
197 | SP_FLOWCONTROL_XONXOFF = 1, | |
198 | /** Hardware flow control using RTS/CTS signals. */ | |
199 | SP_FLOWCONTROL_RTSCTS = 2, | |
200 | /** Hardware flow control using DTR/DSR signals. */ | |
201 | SP_FLOWCONTROL_DTRDSR = 3, | |
202 | }; | |
203 | ||
204 | /** A serial port. */ | |
205 | struct sp_port { | |
206 | /** Name used to open the port. */ | |
207 | char *name; | |
208 | /** @cond 0 */ | |
209 | /** OS-specific port handle. */ | |
210 | #ifdef _WIN32 | |
211 | HANDLE hdl; | |
212 | #else | |
213 | int fd; | |
214 | #endif | |
215 | /** @endcond */ | |
216 | }; | |
217 | ||
218 | /** Configuration for a serial port. */ | |
219 | struct sp_port_config { | |
220 | /** Baud rate in bits per second. */ | |
221 | int baudrate; | |
222 | /** Number of data bits to use. Valid values are 5 to 8. */ | |
223 | int bits; | |
224 | /** Parity setting to use. */ | |
225 | enum sp_parity parity; | |
226 | /** Number of stop bits to use (1 or 2). */ | |
227 | int stopbits; | |
228 | /** RTS pin mode. */ | |
229 | enum sp_rts rts; | |
230 | /** CTS pin mode. */ | |
231 | enum sp_cts cts; | |
232 | /** DTR pin mode. */ | |
233 | enum sp_dtr dtr; | |
234 | /** DSR pin mode. */ | |
235 | enum sp_dsr dsr; | |
236 | /** XON/XOFF flow control mode. */ | |
237 | enum sp_xonxoff xon_xoff; | |
238 | }; | |
239 | ||
240 | /** | |
241 | @defgroup Enumeration Port enumeration | |
242 | @{ | |
243 | */ | |
244 | ||
245 | /** | |
246 | * Obtain a pointer to a new sp_port structure representing the named port. | |
247 | * | |
248 | * The user should allocate a variable of type "struct sp_port *" and pass a | |
249 | * pointer to this to receive the result. | |
250 | * | |
251 | * The result should be freed after use by calling sp_free_port(). | |
252 | * | |
253 | * @return SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation | |
254 | * failure, or SP_ERR_ARG if an invalid pointer is passed. If any error | |
255 | * is returned, the variable pointed to by port_ptr will be set to NULL. | |
256 | * Otherwise, it will be set to point to the newly allocated port. | |
257 | */ | |
258 | enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr); | |
259 | ||
260 | /** | |
261 | * Free a port structure obtained from sp_get_port_by_name() or sp_copy_port(). | |
262 | */ | |
263 | void sp_free_port(struct sp_port *port); | |
264 | ||
265 | /** | |
266 | * List the serial ports available on the system. | |
267 | * | |
268 | * The result obtained is an array of pointers to sp_port structures, | |
269 | * terminated by a NULL. The user should allocate a variable of type | |
270 | * "struct sp_port **" and pass a pointer to this to receive the result. | |
271 | * | |
272 | * The result should be freed after use by calling sp_free_port_list(). | |
273 | * If a port from the list is to be used after freeing the list, it must be | |
274 | * copied first using sp_copy_port(). | |
275 | * | |
276 | * @return SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation | |
277 | * failure, or SP_ERR_ARG if an invalid pointer is passed. If any error | |
278 | * is returned, the variable pointed to by list_ptr will be set to NULL. | |
279 | * Otherwise, it will be set to point to the newly allocated array. | |
280 | */ | |
281 | enum sp_return sp_list_ports(struct sp_port ***list_ptr); | |
282 | ||
283 | /** | |
284 | * Make a new copy of a sp_port structure. | |
285 | * | |
286 | * The user should allocate a variable of type "struct sp_port *" and pass a | |
287 | * pointer to this to receive the result. | |
288 | * | |
289 | * The copy should be freed after use by calling sp_free_port(). | |
290 | * | |
291 | * @return SP_OK on success, SP_ERR_MEM on allocation failure, or SP_ERR_ARG | |
292 | * if an invalid port or pointer is passed. If any error is returned, | |
293 | * the variable pointed to by copy_ptr will be set to NULL. Otherwise, | |
294 | * it will be set to point to the newly allocated copy. | |
295 | */ | |
296 | enum sp_return sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr); | |
297 | ||
298 | /** | |
299 | * Free a port list obtained from sp_list_ports(). | |
300 | * | |
301 | * This will also free all the sp_port structures referred to from the list; | |
302 | * any that are to be retained must be copied first using sp_copy_port(). | |
303 | */ | |
304 | void sp_free_port_list(struct sp_port **ports); | |
305 | ||
306 | /** | |
307 | * @} | |
308 | * @defgroup Ports Opening and closing ports | |
309 | * @{ | |
310 | */ | |
311 | ||
312 | /** | |
313 | * Open the specified serial port. | |
314 | * | |
315 | * @param port Pointer to port structure. | |
316 | * @param flags Flags to use when opening the serial port. | |
317 | * | |
318 | * @return SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation | |
319 | * failure, or SP_ERR_ARG if an invalid port is passed. | |
320 | */ | |
321 | enum sp_return sp_open(struct sp_port *port, enum sp_mode flags); | |
322 | ||
323 | /** | |
324 | * Close the specified serial port. | |
325 | * | |
326 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
327 | * if an invalid port is passed. | |
328 | */ | |
329 | enum sp_return sp_close(struct sp_port *port); | |
330 | ||
331 | /** | |
332 | * @} | |
333 | * @defgroup Configuration Setting port parameters | |
334 | * @{ | |
335 | */ | |
336 | ||
337 | /** | |
338 | * Get the current configuration of the specified serial port. | |
339 | * | |
340 | * The user should allocate a struct sp_port_config, then pass a pointer to it | |
341 | * as the config parameter. The struct will be populated with the port | |
342 | * configuration. | |
343 | * | |
344 | * Any setting that is in a state not recognised or supported by | |
345 | * libserialport will have its value set to -1 in the struct. | |
346 | * | |
347 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
348 | * for invalid arguments. | |
349 | */ | |
350 | enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config); | |
351 | ||
352 | /** | |
353 | * Set the configuration for the specified serial port. | |
354 | * | |
355 | * The user should populate a struct sp_port_config, then pass a pointer to it | |
356 | * as the config parameter. | |
357 | * | |
358 | * To retain the current value of any setting, set that field to -1. | |
359 | * | |
360 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
361 | * for invalid arguments. | |
362 | */ | |
363 | enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *config); | |
364 | ||
365 | /** | |
366 | * Set the baud rate for the specified serial port. | |
367 | * | |
368 | * @param port Pointer to port structure. | |
369 | * @param baudrate Baud rate in bits per second. | |
370 | * | |
371 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
372 | * for invalid arguments. | |
373 | */ | |
374 | enum sp_return sp_set_baudrate(struct sp_port *port, int baudrate); | |
375 | ||
376 | /** | |
377 | * Set the number of data bits for the specified serial port. | |
378 | * | |
379 | * @param port Pointer to port structure. | |
380 | * @param bits Number of data bits to use. Valid values are 5 to 8. | |
381 | * | |
382 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
383 | * for invalid arguments. | |
384 | */ | |
385 | enum sp_return sp_set_bits(struct sp_port *port, int bits); | |
386 | ||
387 | /** | |
388 | * Set the parity for the specified serial port. | |
389 | * | |
390 | * @param port Pointer to port structure. | |
391 | * @param parity Parity setting to use. | |
392 | * | |
393 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
394 | * for invalid arguments. | |
395 | */ | |
396 | enum sp_return sp_set_parity(struct sp_port *port, enum sp_parity parity); | |
397 | ||
398 | /** | |
399 | * Set the number of stop bits for the specified port. | |
400 | * | |
401 | * @param port Pointer to port structure. | |
402 | * @param stopbits Number of stop bits to use (1 or 2). | |
403 | * | |
404 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
405 | * for invalid arguments. | |
406 | */ | |
407 | enum sp_return sp_set_stopbits(struct sp_port *port, int stopbits); | |
408 | ||
409 | /** | |
410 | * Set the flow control type for the specified serial port. | |
411 | * | |
412 | * This function is a wrapper that sets the RTS, CTS, DTR, DSR and | |
413 | * XON/XOFF settings as necessary for the specified flow control | |
414 | * type. For more fine-grained control of these settings, use their | |
415 | * individual configuration functions or the sp_set_config() function. | |
416 | * | |
417 | * @param port Pointer to port structure. | |
418 | * @param flowcontrol Flow control setting to use. | |
419 | * | |
420 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
421 | * for invalid arguments. | |
422 | */ | |
423 | enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol); | |
424 | ||
425 | /** | |
426 | * Set the RTS pin behaviour for the specified port. | |
427 | * | |
428 | * @param port Pointer to port structure. | |
429 | * @param rts RTS pin mode. | |
430 | * | |
431 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
432 | * for invalid arguments. | |
433 | */ | |
434 | enum sp_return sp_set_rts(struct sp_port *port, enum sp_rts rts); | |
435 | ||
436 | /** | |
437 | * Set the CTS pin behaviour for the specified port. | |
438 | * | |
439 | * @param port Pointer to port structure. | |
440 | * @param cts CTS pin mode. | |
441 | * | |
442 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
443 | * for invalid arguments. | |
444 | */ | |
445 | enum sp_return sp_set_cts(struct sp_port *port, enum sp_cts cts); | |
446 | ||
447 | /** | |
448 | * Set the DTR pin behaviour for the specified port. | |
449 | * | |
450 | * @param port Pointer to port structure. | |
451 | * @param dtr DTR pin mode. | |
452 | * | |
453 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
454 | * for invalid arguments. | |
455 | */ | |
456 | enum sp_return sp_set_dtr(struct sp_port *port, enum sp_dtr dtr); | |
457 | ||
458 | /** | |
459 | * Set the RTS pin behaviour for the specified port. | |
460 | * | |
461 | * @param port Pointer to port structure. | |
462 | * @param dsr DSR pin mode. | |
463 | * | |
464 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
465 | * for invalid arguments. | |
466 | */ | |
467 | enum sp_return sp_set_dsr(struct sp_port *port, enum sp_dsr dsr); | |
468 | ||
469 | /** | |
470 | * Configure XON/XOFF flow control for the specified port. | |
471 | * | |
472 | * @param port Pointer to port structure. | |
473 | * @param xon_xoff XON/XOFF flow control mode. | |
474 | * | |
475 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
476 | * for invalid arguments. | |
477 | */ | |
478 | enum sp_return sp_set_xon_xoff(struct sp_port *port, enum sp_xonxoff xon_xoff); | |
479 | ||
480 | /** | |
481 | * @} | |
482 | * @defgroup Data Reading, writing, and flushing data | |
483 | * @{ | |
484 | */ | |
485 | ||
486 | /** | |
487 | * Read bytes from the specified serial port. | |
488 | * | |
489 | * Note that this function may return after reading less than the specified | |
490 | * number of bytes; it is the user's responsibility to iterate as necessary | |
491 | * in this case. | |
492 | * | |
493 | * @param port Pointer to port structure. | |
494 | * @param buf Buffer in which to store the bytes read. | |
495 | * @param count Maximum number of bytes to read. | |
496 | * | |
497 | * @return The number of bytes read, SP_ERR_FAIL on failure, | |
498 | * or SP_ERR_ARG for invalid arguments. | |
499 | */ | |
500 | enum sp_return sp_read(struct sp_port *port, void *buf, size_t count); | |
501 | ||
502 | /** | |
503 | * Write bytes to the specified serial port. | |
504 | * | |
505 | * Note that this function may return after writing less than the specified | |
506 | * number of bytes; it is the user's responsibility to iterate as necessary | |
507 | * in this case. | |
508 | * | |
509 | * @param port Pointer to port structure. | |
510 | * @param buf Buffer containing the bytes to write. | |
511 | * @param count Maximum number of bytes to write. | |
512 | * | |
513 | * @return The number of bytes written, SP_ERR_FAIL on failure, | |
514 | * or SP_ERR_ARG for invalid arguments. | |
515 | */ | |
516 | enum sp_return sp_write(struct sp_port *port, const void *buf, size_t count); | |
517 | ||
518 | /** | |
519 | * Flush serial port buffers. Data in the selected buffer(s) is discarded. | |
520 | * | |
521 | * @param port Pointer to port structure. | |
522 | * @param buffers Which buffer(s) to flush. | |
523 | * | |
524 | * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG | |
525 | * if an invalid port is passed. | |
526 | */ | |
527 | enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers); | |
528 | ||
529 | /** | |
530 | * @} | |
531 | * @defgroup Errors Obtaining error information | |
532 | * @{ | |
533 | */ | |
534 | ||
535 | /** | |
536 | * Get the error code for a failed operation. | |
537 | * | |
538 | * In order to obtain the correct result, this function should be called | |
539 | * straight after the failure, before executing any other system operations. | |
540 | * | |
541 | * @return The system's numeric code for the error that caused the last | |
542 | * operation to fail. | |
543 | */ | |
544 | int sp_last_error_code(void); | |
545 | ||
546 | /** | |
547 | * Get the error message for a failed operation. | |
548 | * | |
549 | * In order to obtain the correct result, this function should be called | |
550 | * straight after the failure, before executing other system operations. | |
551 | * | |
552 | * @return The system's message for the error that caused the last | |
553 | * operation to fail. This string may be allocated by the function, | |
554 | * and should be freed after use by calling sp_free_error_message(). | |
555 | */ | |
556 | char *sp_last_error_message(void); | |
557 | ||
558 | /** | |
559 | * Free an error message returned by sp_last_error_message(). | |
560 | */ | |
561 | void sp_free_error_message(char *message); | |
562 | ||
563 | /** @} */ | |
564 | ||
565 | #ifdef __cplusplus | |
566 | } | |
567 | #endif | |
568 | ||
569 | #endif /* LIBSERIALPORT_H */ |