TheRobotStudio ROSA / MODSERIAL

Fork of the MODSERIAL library by Erik Olieman.

Dependents:   trs_master

Fork of MODSERIAL by Erik -

example3b.cpp@18:21ef26402365, 2011-04-21 (annotated)

Committer:
AjK
Date:
Thu Apr 21 09:20:41 2011 +0000
Revision:
18:21ef26402365
1.18 See ChangeLog.c

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AjK 18:21ef26402365 1 /*
AjK 18:21ef26402365 2 Copyright (c) 2011 Andy Kirkham
AjK 18:21ef26402365 3
AjK 18:21ef26402365 4 Permission is hereby granted, free of charge, to any person obtaining a copy
AjK 18:21ef26402365 5 of this software and associated documentation files (the "Software"), to deal
AjK 18:21ef26402365 6 in the Software without restriction, including without limitation the rights
AjK 18:21ef26402365 7 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
AjK 18:21ef26402365 8 copies of the Software, and to permit persons to whom the Software is
AjK 18:21ef26402365 9 furnished to do so, subject to the following conditions:
AjK 18:21ef26402365 10
AjK 18:21ef26402365 11 The above copyright notice and this permission notice shall be included in
AjK 18:21ef26402365 12 all copies or substantial portions of the Software.
AjK 18:21ef26402365 13
AjK 18:21ef26402365 14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
AjK 18:21ef26402365 15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
AjK 18:21ef26402365 16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AjK 18:21ef26402365 17 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
AjK 18:21ef26402365 18 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
AjK 18:21ef26402365 19 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
AjK 18:21ef26402365 20 THE SOFTWARE.
AjK 18:21ef26402365 21
AjK 18:21ef26402365 22 @file example3b.cpp
AjK 18:21ef26402365 23 @purpose Demos a simple filter.
AjK 18:21ef26402365 24 @version see ChangeLog.c
AjK 18:21ef26402365 25 @author Andy Kirkham
AjK 18:21ef26402365 26 */
AjK 18:21ef26402365 27
AjK 18:21ef26402365 28 /*
AjK 18:21ef26402365 29 This example shows how to use the new callback system. In the old system
AjK 18:21ef26402365 30 Mbed's FunctionPointer[1] type was used to store abd make calls to callbacks.
AjK 18:21ef26402365 31 However, that limits the callback function prototype to void func(void);
AjK 18:21ef26402365 32 which means we cannot pass parameters.
AjK 18:21ef26402365 33
AjK 18:21ef26402365 34 This latest version of MODSERIAL now uses its own callback object. This allows
AjK 18:21ef26402365 35 the passing of a pointer to a class that holds information about the MODSERIAL
AjK 18:21ef26402365 36 object making the callback. As of version 1.18 one critcal piece of information
AjK 18:21ef26402365 37 is passed, a pointer to the MODSERIAL object. This allows callbacks to use the
AjK 18:21ef26402365 38 MODSERIAL functions and data.
AjK 18:21ef26402365 39
AjK 18:21ef26402365 40 Additionally, since MODSERIAL and the callback parameter class MODSERIAL_IRQ_INFO
AjK 18:21ef26402365 41 are friends, MODSERIAL_IRQ_INFO can access the protected functions of MODSERIAL.
AjK 18:21ef26402365 42 This is used to ensure functions that can only be called during a callback
AjK 18:21ef26402365 43 can be invoked from a callback.
AjK 18:21ef26402365 44
AjK 18:21ef26402365 45 [1] http://mbed.org/projects/libraries/svn/mbed/trunk/FunctionPointer.h
AjK 18:21ef26402365 46 */
AjK 18:21ef26402365 47
AjK 18:21ef26402365 48
AjK 18:21ef26402365 49 #ifdef COMPILE_EXAMPLE3_CODE_MODSERIAL
AjK 18:21ef26402365 50
AjK 18:21ef26402365 51 #include "mbed.h"
AjK 18:21ef26402365 52 #include "MODSERIAL.h"
AjK 18:21ef26402365 53
AjK 18:21ef26402365 54 void rxCallback(MODSERIAL_IRQ_INFO *info) {
AjK 18:21ef26402365 55
AjK 18:21ef26402365 56 // Get the pointer to our MODSERIAL object that invoked this callback.
AjK 18:21ef26402365 57 MODSERIAL *pc = info->serial;
AjK 18:21ef26402365 58
AjK 18:21ef26402365 59 // info->serial points at the MODSERIAL instance so we can use it to call
AjK 18:21ef26402365 60 // any of the public MODSERIAL functions that are normally available. So
AjK 18:21ef26402365 61 // there's now no need to use the global version (pc in our case) inside
AjK 18:21ef26402365 62 // callback functions.
AjK 18:21ef26402365 63 char c = pc->rxGetLastChar(); // Where local pc variable is a pointer to the global MODSERIAL pc object.
AjK 18:21ef26402365 64
AjK 18:21ef26402365 65 // The following is rather daft but demos the point.
AjK 18:21ef26402365 66 // Don't allow the letter "A" go into the RX buffer.
AjK 18:21ef26402365 67 // Basically acts as a filter to remove the letter "A"
AjK 18:21ef26402365 68 // if it goes into the RX buffer.
AjK 18:21ef26402365 69 if (c == 'A') {
AjK 18:21ef26402365 70 // Note, we call the MODSERIAL_IRQ_INFO::rxDiscardLastChar() public function which
AjK 18:21ef26402365 71 // is permitted access to the protected version of MODSERIAL::rxDiscardLastChar()
AjK 18:21ef26402365 72 // within MODSERIAL (because they are friends). This ensures rxDiscardLastChar()
AjK 18:21ef26402365 73 // can only be called within an rxCallback function.
AjK 18:21ef26402365 74 info->rxDiscardLastChar();
AjK 18:21ef26402365 75 }
AjK 18:21ef26402365 76 }
AjK 18:21ef26402365 77
AjK 18:21ef26402365 78 #endif