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@8:595258a79939, 2014-11-11 (annotated)

Committer:
creatron
Date:
Tue Nov 11 20:29:49 2014 +0000
Revision:
8:595258a79939
Parent:
7:cfe1e0eafb7e
Child:
9:d49cdc77f867
Working rs485 transmitter, receiver ????

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 8:595258a79939 11 // DigitalOut dir_485 (PB_0);
creatron 8:595258a79939 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 0:044dfba47660 27 // transmit empty flag .. need to set buffer
creatron 0:044dfba47660 28 // in receive mode again after we have transmitted
creatron 0:044dfba47660 29 // all data characters
creatron 1:7091401482c5 30 // rs485.attach(this,
creatron 1:7091401482c5 31 // &dlms_comms::Tx_interrupt,
creatron 7:cfe1e0eafb7e 32 // //RawSerial::TxIrq
creatron 7:cfe1e0eafb7e 33 // Serial::TxIrq);
creatron 8:595258a79939 34 // attach the receiver input to 'run' a method
creatron 7:cfe1e0eafb7e 35
creatron 8:595258a79939 36
creatron 7:cfe1e0eafb7e 37 // when characters received
creatron 7:cfe1e0eafb7e 38 rs485.attach(this,
creatron 7:cfe1e0eafb7e 39 &dlms_comms::Rx_interrupt,
creatron 7:cfe1e0eafb7e 40 //RawSerial::RxIrq
creatron 7:cfe1e0eafb7e 41 Serial::RxIrq);
creatron 7:cfe1e0eafb7e 42 timer = NULL;
creatron 0:044dfba47660 43 debug_uart = NULL;
creatron 3:29454cac7930 44 tx_irq_count = 0l;
creatron 3:29454cac7930 45 rx_irq_count = 0l;
creatron 7:cfe1e0eafb7e 46
creatron 7:cfe1e0eafb7e 47
creatron 8:595258a79939 48 // /** Set the flow control type on the serial port
creatron 8:595258a79939 49 // *
creatron 8:595258a79939 50 // * @param type the flow control type (Disabled, RTS, CTS, RTSCTS)
creatron 8:595258a79939 51 // * @param flow1 the first flow control pin (RTS for RTS or RTSCTS, CTS for CTS)
creatron 8:595258a79939 52 // * @param flow2 the second flow control pin (CTS for RTSCTS)
creatron 8:595258a79939 53 // */
creatron 7:cfe1e0eafb7e 54 // rs485.set_flow_control(RTSCTS , //Flow type,
creatron 7:cfe1e0eafb7e 55 // dir_485, //PB_0, //PinName flow1=NC,
creatron 7:cfe1e0eafb7e 56 // dir_485 //PB_0 //PinName flow2=NC
creatron 7:cfe1e0eafb7e 57 // );
creatron 0:044dfba47660 58 }
creatron 0:044dfba47660 59 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 60 * @brief bq34z110::init_port_expander Put all ports in INPUT mode
creatron 0:044dfba47660 61 * @param parent_uart The debug uart class pionter
creatron 0:044dfba47660 62 * @param parent_timer The main timer (system tick) class pointer
creatron 0:044dfba47660 63 */
creatron 0:044dfba47660 64 void dlms_comms::init (RawSerial * parent_uart,
creatron 0:044dfba47660 65 Timer * parent_timer)
creatron 0:044dfba47660 66 {
creatron 0:044dfba47660 67 // we use the parent timer and debug port
creatron 0:044dfba47660 68 debug_uart = parent_uart;
creatron 0:044dfba47660 69 timer = parent_timer;
creatron 0:044dfba47660 70 //#ifdef DEBUG_DLMS_COMMS
creatron 7:cfe1e0eafb7e 71 //debug_uart->printf (" init_dlms_comms..\r\n");
creatron 0:044dfba47660 72 //#endif
creatron 0:044dfba47660 73 }
creatron 0:044dfba47660 74 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 75 * @brief dlms_comms::initialise This method initialise the rs485 comms port
creatron 0:044dfba47660 76 *
creatron 0:044dfba47660 77 * @param baudrate The RS485 baudrate
creatron 0:044dfba47660 78 * @param bits The RS485 number of bits (8)
creatron 0:044dfba47660 79 * @param parity The parity required 'n','o', 'e'
creatron 0:044dfba47660 80 * @param stop_bits The number of stop bits 1 or 2
creatron 0:044dfba47660 81 */
creatron 0:044dfba47660 82 void dlms_comms::initialise (INT_16 baudrate,
creatron 0:044dfba47660 83 UINT_8 bits,
creatron 0:044dfba47660 84 UINT_8 parity,
creatron 0:044dfba47660 85 UINT_8 stop_bits )
creatron 0:044dfba47660 86 {
creatron 0:044dfba47660 87 // default comms parameters
creatron 0:044dfba47660 88 SerialBase::Parity my_parity = SerialBase::None;
creatron 3:29454cac7930 89 tx_irq_count = 0l;
creatron 3:29454cac7930 90 rx_irq_count = 0l;
creatron 0:044dfba47660 91 // set the class baudrate
creatron 0:044dfba47660 92 rs485.baud(baudrate);
creatron 0:044dfba47660 93 // enable the receiver on the tranceiver buffer chip
creatron 0:044dfba47660 94 dir_485 = 0;
creatron 0:044dfba47660 95 // clear the ring buffer
creatron 0:044dfba47660 96 rx_head_ptr = 0;
creatron 0:044dfba47660 97 rx_tail_ptr = 0;
creatron 0:044dfba47660 98 memset (rx_buffer, 0, sizeof(rx_buffer));
creatron 0:044dfba47660 99 // set the enum parity as required by class
creatron 0:044dfba47660 100 switch (parity)
creatron 0:044dfba47660 101 {
creatron 0:044dfba47660 102 default:
creatron 0:044dfba47660 103 case 'n' :
creatron 0:044dfba47660 104 my_parity = SerialBase::None;
creatron 0:044dfba47660 105 break;
creatron 0:044dfba47660 106 case 'o':
creatron 0:044dfba47660 107 my_parity = SerialBase::Odd;
creatron 0:044dfba47660 108 break;
creatron 0:044dfba47660 109 case 'e':
creatron 0:044dfba47660 110 my_parity = SerialBase::Even;
creatron 0:044dfba47660 111 break;
creatron 0:044dfba47660 112 }
creatron 0:044dfba47660 113 // lets doit .. config the rs485 now
creatron 0:044dfba47660 114 rs485.format((int) bits,
creatron 0:044dfba47660 115 my_parity,
creatron 0:044dfba47660 116 (int) stop_bits);
creatron 7:cfe1e0eafb7e 117 //# ifdef DEBUG_DLMS_COMMS
creatron 7:cfe1e0eafb7e 118 //debug_uart->printf (" init_dlms_comms..Baudrate (%d) %d bits Parity=%c\r\n",
creatron 7:cfe1e0eafb7e 119 // baudrate, bits, parity);
creatron 7:cfe1e0eafb7e 120 //# endif
creatron 0:044dfba47660 121 // dummy send packet to rs485
creatron 0:044dfba47660 122 //send_packet ("\r\nHello cruel world\r\n",12);
creatron 6:70460dcbc43c 123 if ( rs485.readable())
creatron 6:70460dcbc43c 124 rs485.getc();
creatron 0:044dfba47660 125 }
creatron 0:044dfba47660 126 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 127 * @brief dlms_comms::get_dir485 . This method returns the state of the rs485
creatron 0:044dfba47660 128 * direction
creatron 0:044dfba47660 129 */
creatron 0:044dfba47660 130 bool dlms_comms::get_dir485 (void)
creatron 0:044dfba47660 131 {
creatron 0:044dfba47660 132 return dir_485;
creatron 0:044dfba47660 133 }
creatron 0:044dfba47660 134 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 135 * @brief dlms_comms::Tx_interrupt
creatron 0:044dfba47660 136 */
creatron 0:044dfba47660 137 void dlms_comms::Tx_interrupt(void)
creatron 0:044dfba47660 138 {
creatron 3:29454cac7930 139 tx_irq_count++;
creatron 0:044dfba47660 140 // enable the receiver, we are finito with the transmission of characters
creatron 0:044dfba47660 141 // this changes the direction on the transceiver buffer
creatron 8:595258a79939 142 if (dir_485 == 1)
creatron 8:595258a79939 143 dir_485 = 0;
creatron 0:044dfba47660 144 }
creatron 0:044dfba47660 145 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 146 * @brief dlms_comms::Rx_interrupt . This method received all characters from
creatron 0:044dfba47660 147 * the uart and saved it in a ring buffer, 256 bytes long. The CPU only has 16
creatron 0:044dfba47660 148 * byte fifo, this makes it a 256 bit fifo
creatron 0:044dfba47660 149 */
creatron 0:044dfba47660 150 void dlms_comms::Rx_interrupt(void)
creatron 0:044dfba47660 151 {
creatron 0:044dfba47660 152 UINT_8 value;
creatron 3:29454cac7930 153 rx_irq_count++;
creatron 0:044dfba47660 154 // read the uart and place character in ring buffer
creatron 0:044dfba47660 155 value = rs485.getc();
creatron 0:044dfba47660 156 rx_buffer[rx_head_ptr++] = value;
creatron 0:044dfba47660 157 }
creatron 0:044dfba47660 158 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 159 * @brief dlms_comms::available This method return if we have any characters
creatron 0:044dfba47660 160 * available (received on the rs485 port)
creatron 0:044dfba47660 161 * @return true if characters received on the rs485
creatron 0:044dfba47660 162 */
creatron 0:044dfba47660 163 bool dlms_comms::char_available (void)
creatron 0:044dfba47660 164 {
creatron 0:044dfba47660 165 if (rx_head_ptr == rx_tail_ptr)
creatron 0:044dfba47660 166 // nope
creatron 0:044dfba47660 167 return false;
creatron 0:044dfba47660 168 else
creatron 0:044dfba47660 169 return true;
creatron 0:044dfba47660 170 }
creatron 0:044dfba47660 171 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 172 * @brief dlms_comms::get_char This method return the last character received
creatron 0:044dfba47660 173 * on the rs485 port
creatron 0:044dfba47660 174 * @return Unsigned byte
creatron 0:044dfba47660 175 * @note The user must make sure that characters are available before, else
creatron 0:044dfba47660 176 * this method shall wait for the next character, no timeouts yet
creatron 0:044dfba47660 177 */
creatron 0:044dfba47660 178 UINT_8 dlms_comms::get_char (void)
creatron 0:044dfba47660 179 {
creatron 0:044dfba47660 180 // we have to wait for at least on charcter in the ring buffer
creatron 0:044dfba47660 181 while (char_available() == false);
creatron 0:044dfba47660 182 // return the character
creatron 0:044dfba47660 183 return (rx_buffer[rx_tail_ptr++]);
creatron 0:044dfba47660 184 }
creatron 0:044dfba47660 185 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 186 * @brief dlms_comms::send_packet This method sends a serial packet data to the
creatron 0:044dfba47660 187 * rs485 bus, the directoion of the tranceiver chip is changed to transmit and
creatron 0:044dfba47660 188 * the packet is tranmitted.
creatron 0:044dfba47660 189 * @param ptr Pointer address for start of the packet
creatron 0:044dfba47660 190 * @param length Packet length
creatron 0:044dfba47660 191 * @note The direction is changed with a interrupt when the transmitter
creatron 0:044dfba47660 192 * is empty
creatron 0:044dfba47660 193 */
creatron 0:044dfba47660 194 void dlms_comms::send_packet (const UINT_8 *ptr,
creatron 0:044dfba47660 195 const UINT_8 length)
creatron 0:044dfba47660 196 {
creatron 0:044dfba47660 197 // local stack variable
creatron 0:044dfba47660 198 UINT_8 * tmp_ptr =(UINT_8 *) ptr;
creatron 0:044dfba47660 199
creatron 0:044dfba47660 200 // change the tranceiver direction to output
creatron 0:044dfba47660 201 dir_485 = 1;
creatron 0:044dfba47660 202 for (UINT_8 i= 0; i < length; i++)
creatron 0:044dfba47660 203 {
creatron 0:044dfba47660 204 rs485.putc (*tmp_ptr++);
creatron 0:044dfba47660 205 }
creatron 8:595258a79939 206 //
creatron 7:cfe1e0eafb7e 207 rs485.attach(this,
creatron 7:cfe1e0eafb7e 208 &dlms_comms::Tx_interrupt,
creatron 8:595258a79939 209 Serial::TxIrq);
creatron 0:044dfba47660 210 }
creatron 3:29454cac7930 211 UINT_64 dlms_comms::ret_rx_irq_count (void)
creatron 0:044dfba47660 212 {
creatron 3:29454cac7930 213 return rx_irq_count;
creatron 3:29454cac7930 214 }
creatron 3:29454cac7930 215 UINT_64 dlms_comms::ret_tx_irq_count (void)
creatron 3:29454cac7930 216 {
creatron 3:29454cac7930 217 return tx_irq_count;
creatron 0:044dfba47660 218 }
creatron 6:70460dcbc43c 219 bool dlms_comms::ret_dir_485 (void)
creatron 6:70460dcbc43c 220 {
creatron 6:70460dcbc43c 221 return dir_485;
creatron 6:70460dcbc43c 222 }
creatron 0:044dfba47660 223 //----[ the end ]--------------------------------------------------------------