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@11:ca1e0ca3a673, 2014-11-23 (annotated)

Committer:
creatron
Date:
Sun Nov 23 08:13:26 2014 +0000
Revision:
11:ca1e0ca3a673
Parent:
10:e104a1b24165 
Commit to be publised

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 11:ca1e0ca3a673 8 // Instantiate the raw serial (2nd uart) Tx then Rx
creatron 0:044dfba47660 9 RawSerial rs485(PA_9, PA_10);
creatron 11:ca1e0ca3a673 10
creatron 11:ca1e0ca3a673 11 // pin to switch the rs485 buffer direction
creatron 10:e104a1b24165 12 DigitalOut dir_485 (PB_0);
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 Serial::RxIrq);
creatron 7:cfe1e0eafb7e 34 timer = NULL;
creatron 0:044dfba47660 35 debug_uart = NULL;
creatron 3:29454cac7930 36 tx_irq_count = 0l;
creatron 3:29454cac7930 37 rx_irq_count = 0l;
creatron 0:044dfba47660 38 }
creatron 0:044dfba47660 39 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 40 * @brief bq34z110::init_port_expander Put all ports in INPUT mode
creatron 0:044dfba47660 41 * @param parent_uart The debug uart class pionter
creatron 0:044dfba47660 42 * @param parent_timer The main timer (system tick) class pointer
creatron 0:044dfba47660 43 */
creatron 0:044dfba47660 44 void dlms_comms::init (RawSerial * parent_uart,
creatron 0:044dfba47660 45 Timer * parent_timer)
creatron 0:044dfba47660 46 {
creatron 0:044dfba47660 47 // we use the parent timer and debug port
creatron 0:044dfba47660 48 debug_uart = parent_uart;
creatron 0:044dfba47660 49 timer = parent_timer;
creatron 11:ca1e0ca3a673 50 #ifdef DEBUG_DLMS_COMMS
creatron 11:ca1e0ca3a673 51 debug_uart->printf (" init_dlms_comms..\r\n");
creatron 11:ca1e0ca3a673 52 #endif
creatron 0:044dfba47660 53 }
creatron 0:044dfba47660 54 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 55 * @brief dlms_comms::initialise This method initialise the rs485 comms port
creatron 0:044dfba47660 56 *
creatron 0:044dfba47660 57 * @param baudrate The RS485 baudrate
creatron 0:044dfba47660 58 * @param bits The RS485 number of bits (8)
creatron 0:044dfba47660 59 * @param parity The parity required 'n','o', 'e'
creatron 0:044dfba47660 60 * @param stop_bits The number of stop bits 1 or 2
creatron 0:044dfba47660 61 */
creatron 0:044dfba47660 62 void dlms_comms::initialise (INT_16 baudrate,
creatron 0:044dfba47660 63 UINT_8 bits,
creatron 0:044dfba47660 64 UINT_8 parity,
creatron 0:044dfba47660 65 UINT_8 stop_bits )
creatron 0:044dfba47660 66 {
creatron 0:044dfba47660 67 // default comms parameters
creatron 0:044dfba47660 68 SerialBase::Parity my_parity = SerialBase::None;
creatron 3:29454cac7930 69 tx_irq_count = 0l;
creatron 3:29454cac7930 70 rx_irq_count = 0l;
creatron 0:044dfba47660 71 // set the class baudrate
creatron 0:044dfba47660 72 rs485.baud(baudrate);
creatron 0:044dfba47660 73 // enable the receiver on the tranceiver buffer chip
creatron 0:044dfba47660 74 dir_485 = 0;
creatron 0:044dfba47660 75 // clear the ring buffer
creatron 0:044dfba47660 76 rx_head_ptr = 0;
creatron 0:044dfba47660 77 rx_tail_ptr = 0;
creatron 0:044dfba47660 78 memset (rx_buffer, 0, sizeof(rx_buffer));
creatron 0:044dfba47660 79 // set the enum parity as required by class
creatron 0:044dfba47660 80 switch (parity)
creatron 0:044dfba47660 81 {
creatron 0:044dfba47660 82 default:
creatron 0:044dfba47660 83 case 'n' :
creatron 0:044dfba47660 84 my_parity = SerialBase::None;
creatron 0:044dfba47660 85 break;
creatron 0:044dfba47660 86 case 'o':
creatron 0:044dfba47660 87 my_parity = SerialBase::Odd;
creatron 0:044dfba47660 88 break;
creatron 0:044dfba47660 89 case 'e':
creatron 0:044dfba47660 90 my_parity = SerialBase::Even;
creatron 0:044dfba47660 91 break;
creatron 0:044dfba47660 92 }
creatron 0:044dfba47660 93 // lets doit .. config the rs485 now
creatron 0:044dfba47660 94 rs485.format((int) bits,
creatron 0:044dfba47660 95 my_parity,
creatron 0:044dfba47660 96 (int) stop_bits);
creatron 11:ca1e0ca3a673 97 # ifdef DEBUG_DLMS_COMMS
creatron 11:ca1e0ca3a673 98 debug_uart->printf (" init_dlms_comms..Baudrate (%d) %d bits Parity=%c\r\n",
creatron 11:ca1e0ca3a673 99 baudrate, bits, parity);
creatron 0:044dfba47660 100 // dummy send packet to rs485
creatron 11:ca1e0ca3a673 101 send_packet ("\r\nHello cruel world\r\n",12);
creatron 11:ca1e0ca3a673 102 # endif
creatron 6:70460dcbc43c 103 if ( rs485.readable())
creatron 6:70460dcbc43c 104 rs485.getc();
creatron 0:044dfba47660 105 }
creatron 0:044dfba47660 106 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 107 * @brief dlms_comms::get_dir485 . This method returns the state of the rs485
creatron 0:044dfba47660 108 * direction
creatron 0:044dfba47660 109 */
creatron 0:044dfba47660 110 bool dlms_comms::get_dir485 (void)
creatron 0:044dfba47660 111 {
creatron 0:044dfba47660 112 return dir_485;
creatron 0:044dfba47660 113 }
creatron 0:044dfba47660 114 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 115 * @brief dlms_comms::Tx_interrupt
creatron 0:044dfba47660 116 */
creatron 0:044dfba47660 117 void dlms_comms::Tx_interrupt(void)
creatron 0:044dfba47660 118 {
creatron 3:29454cac7930 119 tx_irq_count++;
creatron 11:ca1e0ca3a673 120
creatron 11:ca1e0ca3a673 121 // disable the transmit interrupt
creatron 11:ca1e0ca3a673 122 rs485.attach(NULL, Serial::TxIrq);
creatron 0:044dfba47660 123 // enable the receiver, we are finito with the transmission of characters
creatron 0:044dfba47660 124 // this changes the direction on the transceiver buffer
creatron 9:d49cdc77f867 125 dir_485 = 0;
creatron 0:044dfba47660 126 }
creatron 0:044dfba47660 127 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 128 * @brief dlms_comms::Rx_interrupt . This method received all characters from
creatron 0:044dfba47660 129 * the uart and saved it in a ring buffer, 256 bytes long. The CPU only has 16
creatron 0:044dfba47660 130 * byte fifo, this makes it a 256 bit fifo
creatron 0:044dfba47660 131 */
creatron 0:044dfba47660 132 void dlms_comms::Rx_interrupt(void)
creatron 0:044dfba47660 133 {
creatron 0:044dfba47660 134 UINT_8 value;
creatron 3:29454cac7930 135 rx_irq_count++;
creatron 0:044dfba47660 136 // read the uart and place character in ring buffer
creatron 0:044dfba47660 137 value = rs485.getc();
creatron 0:044dfba47660 138 rx_buffer[rx_head_ptr++] = value;
creatron 0:044dfba47660 139 }
creatron 0:044dfba47660 140 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 141 * @brief dlms_comms::available This method return if we have any characters
creatron 0:044dfba47660 142 * available (received on the rs485 port)
creatron 0:044dfba47660 143 * @return true if characters received on the rs485
creatron 0:044dfba47660 144 */
creatron 0:044dfba47660 145 bool dlms_comms::char_available (void)
creatron 0:044dfba47660 146 {
creatron 0:044dfba47660 147 if (rx_head_ptr == rx_tail_ptr)
creatron 0:044dfba47660 148 // nope
creatron 0:044dfba47660 149 return false;
creatron 0:044dfba47660 150 else
creatron 0:044dfba47660 151 return true;
creatron 0:044dfba47660 152 }
creatron 0:044dfba47660 153 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 154 * @brief dlms_comms::get_char This method return the last character received
creatron 0:044dfba47660 155 * on the rs485 port
creatron 0:044dfba47660 156 * @return Unsigned byte
creatron 0:044dfba47660 157 * @note The user must make sure that characters are available before, else
creatron 0:044dfba47660 158 * this method shall wait for the next character, no timeouts yet
creatron 0:044dfba47660 159 */
creatron 0:044dfba47660 160 UINT_8 dlms_comms::get_char (void)
creatron 0:044dfba47660 161 {
creatron 0:044dfba47660 162 // we have to wait for at least on charcter in the ring buffer
creatron 0:044dfba47660 163 while (char_available() == false);
creatron 0:044dfba47660 164 // return the character
creatron 0:044dfba47660 165 return (rx_buffer[rx_tail_ptr++]);
creatron 0:044dfba47660 166 }
creatron 0:044dfba47660 167 /** ---------------------------------------------------------------------------
creatron 0:044dfba47660 168 * @brief dlms_comms::send_packet This method sends a serial packet data to the
creatron 0:044dfba47660 169 * rs485 bus, the directoion of the tranceiver chip is changed to transmit and
creatron 0:044dfba47660 170 * the packet is tranmitted.
creatron 0:044dfba47660 171 * @param ptr Pointer address for start of the packet
creatron 0:044dfba47660 172 * @param length Packet length
creatron 0:044dfba47660 173 * @note The direction is changed with a interrupt when the transmitter
creatron 0:044dfba47660 174 * is empty
creatron 0:044dfba47660 175 */
creatron 0:044dfba47660 176 void dlms_comms::send_packet (const UINT_8 *ptr,
creatron 0:044dfba47660 177 const UINT_8 length)
creatron 0:044dfba47660 178 {
creatron 0:044dfba47660 179 // local stack variable
creatron 0:044dfba47660 180 UINT_8 * tmp_ptr =(UINT_8 *) ptr;
creatron 0:044dfba47660 181
creatron 0:044dfba47660 182 // change the tranceiver direction to output
creatron 0:044dfba47660 183 dir_485 = 1;
creatron 0:044dfba47660 184 for (UINT_8 i= 0; i < length; i++)
creatron 0:044dfba47660 185 {
creatron 0:044dfba47660 186 rs485.putc (*tmp_ptr++);
creatron 0:044dfba47660 187 }
creatron 7:cfe1e0eafb7e 188 rs485.attach(this,
creatron 7:cfe1e0eafb7e 189 &dlms_comms::Tx_interrupt,
creatron 9:d49cdc77f867 190 Serial::TxIrq);
creatron 0:044dfba47660 191 }
creatron 3:29454cac7930 192 UINT_64 dlms_comms::ret_rx_irq_count (void)
creatron 0:044dfba47660 193 {
creatron 3:29454cac7930 194 return rx_irq_count;
creatron 3:29454cac7930 195 }
creatron 3:29454cac7930 196 UINT_64 dlms_comms::ret_tx_irq_count (void)
creatron 3:29454cac7930 197 {
creatron 3:29454cac7930 198 return tx_irq_count;
creatron 0:044dfba47660 199 }
creatron 6:70460dcbc43c 200 bool dlms_comms::ret_dir_485 (void)
creatron 6:70460dcbc43c 201 {
creatron 6:70460dcbc43c 202 return dir_485;
creatron 6:70460dcbc43c 203 }
creatron 0:044dfba47660 204 //----[ the end ]--------------------------------------------------------------