Diff: dlms_comms.cpp

Revision:

0:044dfba47660

Child:

1:7091401482c5

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dlms_comms.cpp	Tue Nov 11 16:01:12 2014 +0000
@@ -0,0 +1,197 @@
+#include "mbed.h"
+
+#include "RawSerial.h"
+#include "dlms_comms.h"
+
+//#define DEBUG_DLMS_COMMS 
+
+   // Instantiate the raw serial (2nd uart) Tx then Rx
+   RawSerial  rs485(PA_9, PA_10);
+  // pin to switch the rs485 buffer direction
+   DigitalOut dir_485 (PB_0);
+
+/** ---------------------------------------------------------------------------
+ * @brief  C O N S T R U C T O R
+ */
+dlms_comms::dlms_comms (void)
+{
+    // enable the rs485 buffer receiver, 
+    dir_485 = 0;
+
+    // clear the pointers and ring buffer
+    rx_head_ptr = 0;
+    rx_tail_ptr = 0;
+    memset (rx_buffer, 0, sizeof(rx_buffer));
+
+//    // attach the receiver input to 'run' a method
+//    // when characters received
+//    rs485.attach(this,
+//                 &dlms_comms::Rx_interrupt,
+//                 RawSerial::RxIrq);
+    // transmit empty flag .. need to set buffer
+    // in receive mode again after we have transmitted
+    // all data characters
+    rs485.attach(this,
+                 &dlms_comms::Tx_interrupt,
+                 RawSerial::TxIrq);
+    timer = NULL;
+    debug_uart = NULL;
+}
+/** ---------------------------------------------------------------------------
+ * @brief bq34z110::init_port_expander Put all ports in INPUT mode
+ * @param parent_uart  The debug uart class pionter
+ * @param parent_timer The main timer (system tick) class pointer
+ */
+void dlms_comms::init  (RawSerial * parent_uart,
+                        Timer     * parent_timer)
+{  
+    // we use the parent timer and debug port
+    debug_uart  = parent_uart; 
+    timer       = parent_timer;
+//#ifdef DEBUG_DLMS_COMMS    
+    debug_uart->printf ("   init_dlms_comms..\r\n");
+//#endif      
+}
+/** ---------------------------------------------------------------------------
+ * @brief dlms_comms::initialise This method initialise the rs485 comms port
+ *
+ * @param baudrate   The RS485 baudrate
+ * @param bits       The RS485 number of bits (8)
+ * @param parity     The parity required 'n','o', 'e'
+ * @param stop_bits  The number of stop bits 1 or 2
+ */
+void dlms_comms::initialise (INT_16      baudrate,
+                             UINT_8      bits,
+                             UINT_8      parity,
+                             UINT_8      stop_bits )
+{
+    // default comms parameters
+    SerialBase::Parity my_parity = SerialBase::None;
+    irq_count = 0;
+    // set the class baudrate
+    rs485.baud(baudrate);
+    // enable the receiver on the tranceiver buffer chip
+    dir_485 = 0;
+    // clear the ring buffer
+    rx_head_ptr = 0;
+    rx_tail_ptr = 0;
+    memset (rx_buffer, 0, sizeof(rx_buffer));
+    // set the enum parity as required by class
+    switch (parity)
+    {
+    default:
+    case 'n' :
+        my_parity = SerialBase::None;
+        break;
+    case 'o':
+        my_parity = SerialBase::Odd;
+        break;
+    case 'e':
+        my_parity = SerialBase::Even;
+        break;
+    }
+    // lets doit .. config the rs485 now
+    rs485.format((int) bits,
+                 my_parity,
+                 (int) stop_bits);
+#  ifdef DEBUG_DLMS_COMMS    
+     debug_uart->printf ("   init_dlms_comms..Baudrate (%d) %d bits Parity=%c\r\n",
+                          baudrate, bits, parity);
+#  endif                          
+     // dummy send packet to rs485 
+     //send_packet ("\r\nHello cruel world\r\n",12);       
+}
+/** ---------------------------------------------------------------------------
+ * @brief dlms_comms::get_dir485 . This method  returns the state of the rs485
+ * direction
+ */
+bool dlms_comms::get_dir485 (void)
+{
+    return dir_485;
+}
+/** ---------------------------------------------------------------------------
+ * @brief dlms_comms::Tx_interrupt
+ */
+void dlms_comms::Tx_interrupt(void)
+{
+    irq_count++;
+    // enable the receiver, we are finito with the transmission of characters
+    // this changes the direction on the transceiver buffer
+    if (dir_485 == 1)
+        dir_485 = 0;       
+}
+/** ---------------------------------------------------------------------------
+ * @brief dlms_comms::Rx_interrupt . This method received all characters from
+ * the uart and saved it in a ring buffer, 256 bytes long. The CPU only has 16
+ * byte fifo, this makes it a 256 bit fifo
+ */
+void dlms_comms::Rx_interrupt(void)
+{
+    UINT_8 value;
+    // read the uart and place character in ring buffer
+    value = rs485.getc();
+    rx_buffer[rx_head_ptr++] = value;
+}
+/** ---------------------------------------------------------------------------
+ * @brief dlms_comms::available This method return if we have any characters
+ * available (received on the rs485 port)
+ * @return true if characters received on the rs485
+ */
+bool dlms_comms::char_available (void)
+{
+    if (rx_head_ptr == rx_tail_ptr)
+        // nope
+        return false;
+    else
+        return true;
+}
+/** ---------------------------------------------------------------------------
+ * @brief dlms_comms::get_char This method return the last character received
+ * on the rs485 port
+ * @return Unsigned byte
+ * @note The user must make sure that characters are available before, else
+ * this method shall wait for the next character, no timeouts yet
+ */
+UINT_8 dlms_comms::get_char (void)
+{
+    // we have to wait for at least on charcter in the ring buffer
+    while (char_available() == false);
+    // return the character
+    return (rx_buffer[rx_tail_ptr++]);
+}
+/** ---------------------------------------------------------------------------
+ * @brief dlms_comms::send_packet This method sends a serial packet data to the
+ * rs485 bus, the directoion of the tranceiver chip is changed to transmit and
+ * the packet is tranmitted.
+ * @param ptr     Pointer address for start of the packet
+ * @param length  Packet length
+ * @note          The direction is changed with a interrupt when the transmitter
+ *                is empty
+ */
+void dlms_comms::send_packet (const UINT_8  *ptr,
+                              const UINT_8   length)
+{
+    // local stack variable
+    UINT_8 * tmp_ptr =(UINT_8 *) ptr;
+
+    // change the tranceiver direction to output
+    dir_485 = 1;
+    for (UINT_8 i= 0; i < length; i++)
+    {
+        rs485.putc (*tmp_ptr++);
+    }
+}
+UINT_64 dlms_comms::ret_irq_count (void)
+{
+    return irq_count;
+}
+bool dlms_comms::poll_rs485(void)
+{
+    if (rs485.readable ())
+    {
+       Rx_interrupt();
+       return true;
+    }
+    return false;
+}
+//----[ the end ]--------------------------------------------------------------