CAN.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef MBED_CAN_H
00017 #define MBED_CAN_H
00018 
00019 #include "platform.h"
00020 
00021 #if DEVICE_CAN
00022 
00023 #include "can_api.h"
00024 #include "can_helper.h"
00025 #include "FunctionPointer.h"
00026 
00027 namespace mbed {
00028 
00029 /** CANMessage class
00030  */
00031 class CANMessage : public CAN_Message {
00032 
00033 public:
00034     /** Creates empty CAN message.
00035      */
00036     CANMessage() : CAN_Message() {
00037         len    = 8;
00038         type   = CANData;
00039         format = CANStandard;
00040         id     = 0;
00041         memset(data, 0, 8);
00042     }
00043 
00044     /** Creates CAN message with specific content.
00045      */
00046     CANMessage(int _id, const char *_data, char _len = 8, CANType _type = CANData, CANFormat _format = CANStandard) {
00047       len    = _len & 0xF;
00048       type   = _type;
00049       format = _format;
00050       id     = _id;
00051       memcpy(data, _data, _len);
00052     }
00053 
00054     /** Creates CAN remote message.
00055      */
00056     CANMessage(int _id, CANFormat _format = CANStandard) {
00057       len    = 0;
00058       type   = CANRemote;
00059       format = _format;
00060       id     = _id;
00061       memset(data, 0, 8);
00062     }
00063 };
00064 
00065 /** A can bus client, used for communicating with can devices
00066  */
00067 class CAN {
00068 
00069 public:
00070     /** Creates an CAN interface connected to specific pins.
00071      *
00072      *  @param rd read from transmitter
00073      *  @param td transmit to transmitter
00074      *
00075      * Example:
00076      * @code
00077      * #include "mbed.h"
00078      *
00079      * Ticker ticker;
00080      * DigitalOut led1(LED1);
00081      * DigitalOut led2(LED2);
00082      * CAN can1(p9, p10);
00083      * CAN can2(p30, p29);
00084      *
00085      * char counter = 0;
00086      *
00087      * void send() {
00088      *     if(can1.write(CANMessage(1337, &counter, 1))) {
00089      *         printf("Message sent: %d\n", counter);
00090      *         counter++;
00091      *     }
00092      *     led1 = !led1;
00093      * }
00094      *
00095      * int main() {
00096      *     ticker.attach(&send, 1);
00097      *    CANMessage msg;
00098      *     while(1) {
00099      *         if(can2.read(msg)) {
00100      *             printf("Message received: %d\n\n", msg.data[0]);
00101      *             led2 = !led2;
00102      *         }
00103      *         wait(0.2);
00104      *     }
00105      * }
00106      * @endcode
00107      */
00108     CAN(PinName rd, PinName td);
00109     virtual ~CAN();
00110 
00111     /** Set the frequency of the CAN interface
00112      *
00113      *  @param hz The bus frequency in hertz
00114      *
00115      *  @returns
00116      *    1 if successful,
00117      *    0 otherwise
00118      */
00119     int frequency(int hz);
00120 
00121     /** Write a CANMessage to the bus.
00122      *
00123      *  @param msg The CANMessage to write.
00124      *
00125      *  @returns
00126      *    0 if write failed,
00127      *    1 if write was successful
00128      */
00129     int write(CANMessage msg);
00130 
00131     /** Read a CANMessage from the bus.
00132      *
00133      *  @param msg A CANMessage to read to.
00134      *  @param handle message filter handle (0 for any message)
00135      *
00136      *  @returns
00137      *    0 if no message arrived,
00138      *    1 if message arrived
00139      */
00140     int read(CANMessage &msg, int handle = 0);
00141 
00142     /** Reset CAN interface.
00143      *
00144      * To use after error overflow.
00145      */
00146     void reset();
00147 
00148     /** Puts or removes the CAN interface into silent monitoring mode
00149      *
00150      *  @param silent boolean indicating whether to go into silent mode or not
00151      */
00152     void monitor(bool silent);
00153 
00154     enum Mode {
00155         Reset = 0,
00156         Normal,
00157         Silent,
00158         LocalTest,
00159         GlobalTest,
00160         SilentTest
00161     };
00162 
00163     /** Change CAN operation to the specified mode
00164      *
00165      *  @param mode The new operation mode (CAN::Normal, CAN::Silent, CAN::LocalTest, CAN::GlobalTest, CAN::SilentTest)
00166      *
00167      *  @returns
00168      *    0 if mode change failed or unsupported,
00169      *    1 if mode change was successful
00170      */
00171     int mode(Mode mode);
00172 
00173     /** Filter out incomming messages
00174      *
00175      *  @param id the id to filter on
00176      *  @param mask the mask applied to the id
00177      *  @param format format to filter on (Default CANAny)
00178      *  @param handle message filter handle (Optional)
00179      *
00180      *  @returns
00181      *    0 if filter change failed or unsupported,
00182      *    new filter handle if successful
00183      */
00184     int filter(unsigned int id, unsigned int mask, CANFormat format = CANAny, int handle = 0);
00185 
00186     /** Returns number of read errors to detect read overflow errors.
00187      */
00188     unsigned char rderror();
00189 
00190     /** Returns number of write errors to detect write overflow errors.
00191      */
00192     unsigned char tderror();
00193 
00194     enum IrqType {
00195         RxIrq = 0,
00196         TxIrq,
00197         EwIrq,
00198         DoIrq,
00199         WuIrq,
00200         EpIrq,
00201         AlIrq,
00202         BeIrq,
00203         IdIrq
00204     };
00205 
00206     /** Attach a function to call whenever a CAN frame received interrupt is
00207      *  generated.
00208      *
00209      *  @param fptr A pointer to a void function, or 0 to set as none
00210      *  @param event Which CAN interrupt to attach the member function to (CAN::RxIrq for message received, CAN::TxIrq for transmitted or aborted, CAN::EwIrq for error warning, CAN::DoIrq for data overrun, CAN::WuIrq for wake-up, CAN::EpIrq for error passive, CAN::AlIrq for arbitration lost, CAN::BeIrq for bus error)
00211      */
00212     void attach(void (*fptr)(void), IrqType type=RxIrq);
00213 
00214    /** Attach a member function to call whenever a CAN frame received interrupt
00215     *  is generated.
00216     *
00217     *  @param tptr pointer to the object to call the member function on
00218     *  @param mptr pointer to the member function to be called
00219     *  @param event Which CAN interrupt to attach the member function to (CAN::RxIrq for message received, TxIrq for transmitted or aborted, EwIrq for error warning, DoIrq for data overrun, WuIrq for wake-up, EpIrq for error passive, AlIrq for arbitration lost, BeIrq for bus error)
00220     */
00221    template<typename T>
00222    void attach(T* tptr, void (T::*mptr)(void), IrqType type=RxIrq) {
00223         if((mptr != NULL) && (tptr != NULL)) {
00224             _irq[type].attach(tptr, mptr);
00225             can_irq_set(&_can, (CanIrqType)type, 1);
00226         }
00227         else {
00228             can_irq_set(&_can, (CanIrqType)type, 0);
00229         }
00230     }
00231 
00232     static void _irq_handler(uint32_t id, CanIrqType type);
00233 
00234 protected:
00235     can_t           _can;
00236     FunctionPointer _irq[9];
00237 };
00238 
00239 } // namespace mbed
00240 
00241 #endif
00242 
00243 #endif    // MBED_CAN_H