RFM12B.h

00001 /*
00002  RFM12B Library. Based on work done by JeeLabs.org ported to mBed by SK Pang.
00003  http://jeelabs.net/projects/cafe/wiki/RF12
00004  Jan 2012 skpang.co.uk
00005 
00006  RFM12B Library (Moteino Comunication Protocol). Based on work done by Felix Rusu ported to mBed by Hugo Rodrigues
00007  http://lowpowerlab.com/blog/2012/12/28/rfm12b-arduino-library/
00008  May 2013 Hugo Rodrigues
00009 
00010  http://opensource.org/licenses/mit-license.php
00011 
00012  Permission is hereby granted, free of charge, to any person obtaining a copy
00013  of this software and associated documentation files (the "Software"), to deal
00014  in the Software without restriction, including without limitation the rights
00015  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00016  copies of the Software, and to permit persons to whom the Software is
00017  furnished to do so, subject to the following conditions:
00018 
00019  The above copyright notice and this permission notice shall be included in
00020  all copies or substantial portions of the Software.
00021 
00022  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00023  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00024  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00025  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00026  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00027  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00028  THE SOFTWARE.
00029  */
00030 
00031 #ifndef _RFM12B_H
00032 #define _RFM12B_H
00033 
00034 #include "mbed.h"
00035 
00036 /// RF12 Maximum message size in bytes.
00037 #define RF12_MAXDATA    128
00038 /// Max transmit/receive buffer: 4 header + data + 2 crc bytes
00039 #define RF_MAX          (RF12_MAXDATA + 6)
00040 
00041 #define RF12_433MHZ     1
00042 #define RF12_868MHZ     2
00043 #define RF12_915MHZ     3
00044 
00045 #define RF12_HDR_IDMASK      0x7F
00046 #define RF12_HDR_ACKCTLMASK  0x80
00047 #define RF12_DESTID   (rf12_hdr1 & RF12_HDR_IDMASK)
00048 #define RF12_SOURCEID (rf12_hdr2 & RF12_HDR_IDMASK)
00049 
00050 // shorthands to simplify sending out the proper ACK when requested
00051 #define RF12_WANTS_ACK ((rf12_hdr2 & RF12_HDR_ACKCTLMASK) && !(rf12_hdr1 & RF12_HDR_ACKCTLMASK))
00052 
00053 /// Shorthand for RF12 group byte in rf12_buf.
00054 #define rf12_grp        rf12_buf[0]
00055 /// pointer to 1st header byte in rf12_buf (CTL + DESTINATIONID)
00056 #define rf12_hdr1        rf12_buf[1]
00057 /// pointer to 2nd header byte in rf12_buf (ACK + SOURCEID)
00058 #define rf12_hdr2        rf12_buf[2]
00059 
00060 /// Shorthand for RF12 length byte in rf12_buf.
00061 #define rf12_len        rf12_buf[3]
00062 /// Shorthand for first RF12 data byte in rf12_buf.
00063 #define rf12_data       (rf12_buf + 4)
00064 
00065 // RF12 command codes
00066 #define RF_RECEIVER_ON  0x82DD
00067 #define RF_XMITTER_ON   0x823D
00068 #define RF_IDLE_MODE    0x820D
00069 #define RF_SLEEP_MODE   0x8205
00070 #define RF_WAKEUP_MODE  0x8207
00071 #define RF_TXREG_WRITE  0xB800
00072 #define RF_RX_FIFO_READ 0xB000
00073 #define RF_WAKEUP_TIMER 0xE000
00074 
00075 //RF12 status bits
00076 #define RF_LBD_BIT      0x0400
00077 #define RF_RSSI_BIT     0x0100
00078 
00079 //#define DEBUG
00080 
00081 // transceiver states, these determine what to do with each interrupt
00082 enum {
00083     TXCRC1, TXCRC2, TXTAIL, TXDONE, TXIDLE, TXRECV, TXPRE1, TXPRE2, TXPRE3, TXSYN1, TXSYN2,
00084 };
00085 
00086 class RFM12B
00087 {
00088 
00089 public:
00090     /* Constructor */
00091     RFM12B(PinName SDI, PinName SDO, PinName SCK, PinName NCS, PinName NIRQ, PinName NIRQ_LED);
00092 
00093     /* Initialises the RFM12B module */
00094     void Initialize(uint8_t nodeid, uint8_t freqBand, uint8_t groupid=0xAA, uint8_t txPower=0, uint8_t airKbps=0x08);
00095 
00096     void ReceiveStart(void);
00097     bool ReceiveComplete(void);
00098     bool CanSend();
00099 
00100     void SendStart(uint8_t toNodeId, bool requestACK = false, bool sendACK = false);
00101     void SendStart(uint8_t toNodeId, const void* sendBuf, uint8_t sendLen, bool requestACK = false,
00102                    bool sendACK = false);
00103     void SendACK(const void* sendBuf = "", uint8_t sendLen = 0);
00104     void Send(uint8_t toNodeId, const void* sendBuf, uint8_t sendLen, bool requestACK = false);
00105 
00106     void Sleep(int n);
00107     void Sleep();
00108     void Wakeup();
00109     bool LowBattery();
00110 
00111     volatile uint8_t * GetData();
00112     uint8_t GetDataLen(void);                   // how many bytes were received
00113     uint8_t GetSender(void);
00114 
00115     bool ACKRequested();
00116     bool ACKReceived(uint8_t fromNodeID = 0);
00117 
00118     void Encryption(bool encrypt);              // does en-/decryption
00119     void SetEncryptionKey(const uint8_t* key);  // set encryption key
00120 
00121     bool CRC_Pass(void);
00122 
00123 protected:
00124     /* SPI module */
00125     SPI spi;
00126 
00127     /* Other digital pins */
00128     DigitalOut NCS;
00129     InterruptIn NIRQ;
00130     DigitalIn NIRQ_in;
00131     DigitalOut NIRQ_LED;
00132 
00133     volatile uint8_t nodeID;                    // address of this node
00134     volatile uint8_t networkID;                 // network group
00135 
00136     volatile uint8_t* Data;
00137     volatile uint8_t* DataLen;
00138 
00139     void InterruptHandler();                    // interrupt routine for data reception
00140 
00141     int writeCmd(int cmd);                      // write a command to the RF module
00142     uint16_t crc16_update(uint16_t crc, uint8_t data);
00143     uint16_t xfer(uint16_t cmd);
00144     uint8_t byte(uint8_t out);
00145 
00146 private:
00147     volatile uint8_t rf12_buf[RF_MAX];          // recv/xmit buf, including hdr & crc bytes
00148 
00149     volatile uint8_t rxfill;                    // number of data bytes in rf12_buf
00150     volatile int8_t rxstate;                    // current transceiver state
00151     volatile uint16_t rf12_crc;                 // running crc value
00152     uint32_t seqNum;                            // encrypted send sequence number
00153     uint32_t cryptKey[4];                       // encryption key to use
00154     long rf12_seq;                              // seq number of encrypted packet (or -1)
00155 
00156     bool useEncryption;
00157 };
00158 
00159 #endif /* _RFM12B_H */