Diff: tinymal_modbus.h

Revision:

0:4f5da8a923c4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tinymal_modbus.h	Fri Feb 22 14:31:13 2019 +0000
@@ -0,0 +1,89 @@
+/** @file tinymal_modbus.h
+ *  Library to implement a ModBus slave in mbed. 
+ *  @note Currently supports 38400 baud rate only.
+ * 
+ *  @author Fernando Cosentino
+ *  os.mbed.com/users/fbcosentino
+ *
+ *  Example:
+ *  @code
+ *  #include "mbed.h"
+ *  #include "tinymal_modbus.h"
+ *
+ *  // pins are for LPC11U35
+ *  Serial rs485(P0_19, P0_18);  // a serial port object
+ *  DigitalOut driver_pin(P0_2); // direction driver pin
+ *  DigitalOut coil1(P0_20);     // a coil - this is the application
+ *
+ *  int main() {
+ *      rs485.baud(38400);
+ *      tinymod_Init(&rs485, &driver_pin);
+ *      tinymod_Address(10);
+ *
+ *      // tiny_regs is the array containing the modbus registers
+ *      tiny_regs[0] = 0; // Sets an initial value to register 0
+ *
+ *      while(1) {
+ *          // call this periodically to process the messages
+ *          tinymod_Check();
+ *
+ *          // make the coil reflect the internal modbus register
+ *          if (tiny_regs[0] > 0) {
+ *              coil1 = 1;
+ *          }
+ *          else {
+ *              coil1 = 0;
+ *          }
+ *      } 
+ *  }
+ *  @endcode
+ */
+
+#include "mbed.h"
+
+#define TINYMOD_NUM_REGS    16
+
+#define TINYMOD_MODE_SLAVE   0
+#define TINYMOD_MODE_MASTER  1
+
+#define MODBUS_FUNC_READ            3
+#define MODBUS_FUNC_WRITE_SINGLE    6
+#define MODBUS_FUNC_WRITE_MULT      16
+
+
+extern uint8_t tinymod_address;
+extern int tinymod_mode;
+
+
+/**
+ *  Array storing the register values - your application will work with this.
+ */
+extern uint16_t tiny_regs[TINYMOD_NUM_REGS];
+
+
+/**
+ *  Initialises the internal Modbus receiver based on the specified serial port
+ *  direction driver objects. You must initialise those objects yourself before
+ *  instancing the tinymal modbus object.
+ *
+ *  @param ser_obj Serial instance of the Serial class.
+ *  @param driver_obj Digital output pin instance of the DigitalOut class
+ */
+void tinymod_Init(Serial * ser_obj, DigitalOut * driver_obj);
+
+/**
+ *  Sets the listening address for this device. Valid addresses are in the
+ *  range of 0 - 247 decimal (0x00 - 0xF7).
+ *
+ *  @param addr Address this device should respond to (0 - 247)
+ */
+void tinymod_Address(uint8_t addr);
+
+/**
+ *  Internally processes any received messages - you must call this as often
+ *  as possible (ideally once per main loop if your main loop is short).
+ *  Messages are not automatically processed to keep interrupt handling to the
+ *  bare minimum, so you have the freedom to decide when you are going to spend
+ *  processor time processing the message via this function call.
+ */
+void tinymod_Check(void);
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