Gerrie de Jager / Mbed 2 deprecated Creatron_RS485

This is a RS485 class that uses the second UART and was tested on a Nucleo F030R8. A main demo program howto use the class is included. This class control the direction pin on the transceiver buffer automatically, and used transmit and receive interrupts. Ring buffers (256 bytes) are implemented on both transmission and reception. It assumes a ADM3485 'type' buffer where pins 2 ans 3 are connected and seen as direction. This test program could easily be adapted as base for other programs.

Dependencies:   mbed

dlms_comms.cpp@10:e104a1b24165, 2014-11-11 (annotated)

Committer:
creatron
Date:
Tue Nov 11 21:02:06 2014 +0000
Revision:
10:e104a1b24165
Parent:
9:d49cdc77f867
Child:
11:ca1e0ca3a673
Commit a working rs485 with the correct dir485 pin

Who changed what in which revision?

UserRevisionLine numberNew contents of line
creatron 0:044dfba47660 1 #include "mbed.h"
creatron 0:044dfba47660 2
creatron 0:044dfba47660 3 #include "RawSerial.h"
creatron 0:044dfba47660 4 #include "dlms_comms.h"
creatron 0:044dfba47660 5
creatron 0:044dfba47660 6 //#define DEBUG_DLMS_COMMS
creatron 0:044dfba47660 7
creatron 0:044dfba47660 8 // Instantiate the raw serial (2nd uart) Tx then Rx
creatron 0:044dfba47660 9 RawSerial rs485(PA_9, PA_10);
creatron 0:044dfba47660 10 // pin to switch the rs485 buffer direction
creatron 10:e104a1b24165 11 DigitalOut dir_485 (PB_0);
creatron 10:e104a1b24165 12 //DigitalOut dir_485 (D7);
creatron 8:595258a79939 13
creatron 0:044dfba47660 14 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 15 * @brief C O N S T R U C T O R
creatron 0:044dfba47660 16 */
creatron 0:044dfba47660 17 dlms_comms::dlms_comms (void)
creatron 0:044dfba47660 18 {
creatron 0:044dfba47660 19 // enable the rs485 buffer receiver,
creatron 0:044dfba47660 20 dir_485 = 0;
creatron 0:044dfba47660 21
creatron 0:044dfba47660 22 // clear the pointers and ring buffer
creatron 0:044dfba47660 23 rx_head_ptr = 0;
creatron 0:044dfba47660 24 rx_tail_ptr = 0;
creatron 0:044dfba47660 25 memset (rx_buffer, 0, sizeof(rx_buffer));
creatron 0:044dfba47660 26
creatron 8:595258a79939 27 // attach the receiver input to 'run' a method
creatron 9:d49cdc77f867 28 rs485.attach(NULL, Serial::TxIrq);
creatron 8:595258a79939 29
creatron 7:cfe1e0eafb7e 30 // when characters received
creatron 7:cfe1e0eafb7e 31 rs485.attach(this,
creatron 7:cfe1e0eafb7e 32 &dlms_comms::Rx_interrupt,
creatron 7:cfe1e0eafb7e 33 //RawSerial::RxIrq
creatron 7:cfe1e0eafb7e 34 Serial::RxIrq);
creatron 7:cfe1e0eafb7e 35 timer = NULL;
creatron 0:044dfba47660 36 debug_uart = NULL;
creatron 3:29454cac7930 37 tx_irq_count = 0l;
creatron 3:29454cac7930 38 rx_irq_count = 0l;
creatron 7:cfe1e0eafb7e 39
creatron 7:cfe1e0eafb7e 40
creatron 8:595258a79939 41 // /** Set the flow control type on the serial port
creatron 8:595258a79939 42 // *
creatron 8:595258a79939 43 // * @param type the flow control type (Disabled, RTS, CTS, RTSCTS)
creatron 8:595258a79939 44 // * @param flow1 the first flow control pin (RTS for RTS or RTSCTS, CTS for CTS)
creatron 8:595258a79939 45 // * @param flow2 the second flow control pin (CTS for RTSCTS)
creatron 8:595258a79939 46 // */
creatron 7:cfe1e0eafb7e 47 // rs485.set_flow_control(RTSCTS , //Flow type,
creatron 7:cfe1e0eafb7e 48 // dir_485, //PB_0, //PinName flow1=NC,
creatron 7:cfe1e0eafb7e 49 // dir_485 //PB_0 //PinName flow2=NC
creatron 7:cfe1e0eafb7e 50 // );
creatron 0:044dfba47660 51 }
creatron 0:044dfba47660 52 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 53 * @brief bq34z110::init_port_expander Put all ports in INPUT mode
creatron 0:044dfba47660 54 * @param parent_uart The debug uart class pionter
creatron 0:044dfba47660 55 * @param parent_timer The main timer (system tick) class pointer
creatron 0:044dfba47660 56 */
creatron 0:044dfba47660 57 void dlms_comms::init (RawSerial * parent_uart,
creatron 0:044dfba47660 58 Timer * parent_timer)
creatron 0:044dfba47660 59 {
creatron 0:044dfba47660 60 // we use the parent timer and debug port
creatron 0:044dfba47660 61 debug_uart = parent_uart;
creatron 0:044dfba47660 62 timer = parent_timer;
creatron 0:044dfba47660 63 //#ifdef DEBUG_DLMS_COMMS
creatron 7:cfe1e0eafb7e 64 //debug_uart->printf (" init_dlms_comms..\r\n");
creatron 0:044dfba47660 65 //#endif
creatron 0:044dfba47660 66 }
creatron 0:044dfba47660 67 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 68 * @brief dlms_comms::initialise This method initialise the rs485 comms port
creatron 0:044dfba47660 69 *
creatron 0:044dfba47660 70 * @param baudrate The RS485 baudrate
creatron 0:044dfba47660 71 * @param bits The RS485 number of bits (8)
creatron 0:044dfba47660 72 * @param parity The parity required 'n','o', 'e'
creatron 0:044dfba47660 73 * @param stop_bits The number of stop bits 1 or 2
creatron 0:044dfba47660 74 */
creatron 0:044dfba47660 75 void dlms_comms::initialise (INT_16 baudrate,
creatron 0:044dfba47660 76 UINT_8 bits,
creatron 0:044dfba47660 77 UINT_8 parity,
creatron 0:044dfba47660 78 UINT_8 stop_bits )
creatron 0:044dfba47660 79 {
creatron 0:044dfba47660 80 // default comms parameters
creatron 0:044dfba47660 81 SerialBase::Parity my_parity = SerialBase::None;
creatron 3:29454cac7930 82 tx_irq_count = 0l;
creatron 3:29454cac7930 83 rx_irq_count = 0l;
creatron 0:044dfba47660 84 // set the class baudrate
creatron 0:044dfba47660 85 rs485.baud(baudrate);
creatron 0:044dfba47660 86 // enable the receiver on the tranceiver buffer chip
creatron 0:044dfba47660 87 dir_485 = 0;
creatron 0:044dfba47660 88 // clear the ring buffer
creatron 0:044dfba47660 89 rx_head_ptr = 0;
creatron 0:044dfba47660 90 rx_tail_ptr = 0;
creatron 0:044dfba47660 91 memset (rx_buffer, 0, sizeof(rx_buffer));
creatron 0:044dfba47660 92 // set the enum parity as required by class
creatron 0:044dfba47660 93 switch (parity)
creatron 0:044dfba47660 94 {
creatron 0:044dfba47660 95 default:
creatron 0:044dfba47660 96 case 'n' :
creatron 0:044dfba47660 97 my_parity = SerialBase::None;
creatron 0:044dfba47660 98 break;
creatron 0:044dfba47660 99 case 'o':
creatron 0:044dfba47660 100 my_parity = SerialBase::Odd;
creatron 0:044dfba47660 101 break;
creatron 0:044dfba47660 102 case 'e':
creatron 0:044dfba47660 103 my_parity = SerialBase::Even;
creatron 0:044dfba47660 104 break;
creatron 0:044dfba47660 105 }
creatron 0:044dfba47660 106 // lets doit .. config the rs485 now
creatron 0:044dfba47660 107 rs485.format((int) bits,
creatron 0:044dfba47660 108 my_parity,
creatron 0:044dfba47660 109 (int) stop_bits);
creatron 7:cfe1e0eafb7e 110 //# ifdef DEBUG_DLMS_COMMS
creatron 7:cfe1e0eafb7e 111 //debug_uart->printf (" init_dlms_comms..Baudrate (%d) %d bits Parity=%c\r\n",
creatron 7:cfe1e0eafb7e 112 // baudrate, bits, parity);
creatron 7:cfe1e0eafb7e 113 //# endif
creatron 0:044dfba47660 114 // dummy send packet to rs485
creatron 0:044dfba47660 115 //send_packet ("\r\nHello cruel world\r\n",12);
creatron 6:70460dcbc43c 116 if ( rs485.readable())
creatron 6:70460dcbc43c 117 rs485.getc();
creatron 0:044dfba47660 118 }
creatron 0:044dfba47660 119 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 120 * @brief dlms_comms::get_dir485 . This method returns the state of the rs485
creatron 0:044dfba47660 121 * direction
creatron 0:044dfba47660 122 */
creatron 0:044dfba47660 123 bool dlms_comms::get_dir485 (void)
creatron 0:044dfba47660 124 {
creatron 0:044dfba47660 125 return dir_485;
creatron 0:044dfba47660 126 }
creatron 0:044dfba47660 127 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 128 * @brief dlms_comms::Tx_interrupt
creatron 0:044dfba47660 129 */
creatron 0:044dfba47660 130 void dlms_comms::Tx_interrupt(void)
creatron 0:044dfba47660 131 {
creatron 3:29454cac7930 132 tx_irq_count++;
creatron 0:044dfba47660 133 // enable the receiver, we are finito with the transmission of characters
creatron 0:044dfba47660 134 // this changes the direction on the transceiver buffer
creatron 9:d49cdc77f867 135 rs485.attach(NULL, Serial::TxIrq);
creatron 9:d49cdc77f867 136 dir_485 = 0;
creatron 0:044dfba47660 137 }
creatron 0:044dfba47660 138 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 139 * @brief dlms_comms::Rx_interrupt . This method received all characters from
creatron 0:044dfba47660 140 * the uart and saved it in a ring buffer, 256 bytes long. The CPU only has 16
creatron 0:044dfba47660 141 * byte fifo, this makes it a 256 bit fifo
creatron 0:044dfba47660 142 */
creatron 0:044dfba47660 143 void dlms_comms::Rx_interrupt(void)
creatron 0:044dfba47660 144 {
creatron 0:044dfba47660 145 UINT_8 value;
creatron 3:29454cac7930 146 rx_irq_count++;
creatron 0:044dfba47660 147 // read the uart and place character in ring buffer
creatron 0:044dfba47660 148 value = rs485.getc();
creatron 0:044dfba47660 149 rx_buffer[rx_head_ptr++] = value;
creatron 0:044dfba47660 150 }
creatron 0:044dfba47660 151 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 152 * @brief dlms_comms::available This method return if we have any characters
creatron 0:044dfba47660 153 * available (received on the rs485 port)
creatron 0:044dfba47660 154 * @return true if characters received on the rs485
creatron 0:044dfba47660 155 */
creatron 0:044dfba47660 156 bool dlms_comms::char_available (void)
creatron 0:044dfba47660 157 {
creatron 0:044dfba47660 158 if (rx_head_ptr == rx_tail_ptr)
creatron 0:044dfba47660 159 // nope
creatron 0:044dfba47660 160 return false;
creatron 0:044dfba47660 161 else
creatron 0:044dfba47660 162 return true;
creatron 0:044dfba47660 163 }
creatron 0:044dfba47660 164 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 165 * @brief dlms_comms::get_char This method return the last character received
creatron 0:044dfba47660 166 * on the rs485 port
creatron 0:044dfba47660 167 * @return Unsigned byte
creatron 0:044dfba47660 168 * @note The user must make sure that characters are available before, else
creatron 0:044dfba47660 169 * this method shall wait for the next character, no timeouts yet
creatron 0:044dfba47660 170 */
creatron 0:044dfba47660 171 UINT_8 dlms_comms::get_char (void)
creatron 0:044dfba47660 172 {
creatron 0:044dfba47660 173 // we have to wait for at least on charcter in the ring buffer
creatron 0:044dfba47660 174 while (char_available() == false);
creatron 0:044dfba47660 175 // return the character
creatron 0:044dfba47660 176 return (rx_buffer[rx_tail_ptr++]);
creatron 0:044dfba47660 177 }
creatron 0:044dfba47660 178 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 179 * @brief dlms_comms::send_packet This method sends a serial packet data to the
creatron 0:044dfba47660 180 * rs485 bus, the directoion of the tranceiver chip is changed to transmit and
creatron 0:044dfba47660 181 * the packet is tranmitted.
creatron 0:044dfba47660 182 * @param ptr Pointer address for start of the packet
creatron 0:044dfba47660 183 * @param length Packet length
creatron 0:044dfba47660 184 * @note The direction is changed with a interrupt when the transmitter
creatron 0:044dfba47660 185 * is empty
creatron 0:044dfba47660 186 */
creatron 0:044dfba47660 187 void dlms_comms::send_packet (const UINT_8 *ptr,
creatron 0:044dfba47660 188 const UINT_8 length)
creatron 0:044dfba47660 189 {
creatron 0:044dfba47660 190 // local stack variable
creatron 0:044dfba47660 191 UINT_8 * tmp_ptr =(UINT_8 *) ptr;
creatron 0:044dfba47660 192
creatron 0:044dfba47660 193 // change the tranceiver direction to output
creatron 0:044dfba47660 194 dir_485 = 1;
creatron 0:044dfba47660 195 for (UINT_8 i= 0; i < length; i++)
creatron 0:044dfba47660 196 {
creatron 0:044dfba47660 197 rs485.putc (*tmp_ptr++);
creatron 0:044dfba47660 198 }
creatron 7:cfe1e0eafb7e 199 rs485.attach(this,
creatron 7:cfe1e0eafb7e 200 &dlms_comms::Tx_interrupt,
creatron 9:d49cdc77f867 201 Serial::TxIrq);
creatron 0:044dfba47660 202 }
creatron 3:29454cac7930 203 UINT_64 dlms_comms::ret_rx_irq_count (void)
creatron 0:044dfba47660 204 {
creatron 3:29454cac7930 205 return rx_irq_count;
creatron 3:29454cac7930 206 }
creatron 3:29454cac7930 207 UINT_64 dlms_comms::ret_tx_irq_count (void)
creatron 3:29454cac7930 208 {
creatron 3:29454cac7930 209 return tx_irq_count;
creatron 0:044dfba47660 210 }
creatron 6:70460dcbc43c 211 bool dlms_comms::ret_dir_485 (void)
creatron 6:70460dcbc43c 212 {
creatron 6:70460dcbc43c 213 return dir_485;
creatron 6:70460dcbc43c 214 }
creatron 0:044dfba47660 215 //----[ the end ]--------------------------------------------------------------