#include <pthread.h>
#include <unistd.h>
#include <modbus/modbus.h>
+#include <errno.h>
-#define MIN_DISPENSE_PERIOD 5
+#define MIN_DISPENSE_PERIOD 2
+#define COKE_RECONNECT_RATELIMIT 2
// === CONSTANTS ===
const int ciCoke_MinPeriod = 5;
-const int ciCoke_DropBitBase = 0;
-const int ciCoke_StatusBitBase = 0;
+const int ciCoke_DropBitBase = 1024;
+const int ciCoke_StatusBitBase = 16;
// === IMPORTS ===
int Coke_InitHandler();
int Coke_CanDispense(int User, int Item);
int Coke_DoDispense(int User, int Item);
+ int Coke_int_ConnectToPLC(void);
+ int Coke_int_GetSlotFromItem(int Item, int bDispensing);
+ int Coke_int_IsSlotEmpty(int Slot);
+ int Coke_int_DropSlot(int Slot);
+static int _ReadBit(int BitNum, uint8_t *Value);
+static int _WriteBit(int BitNum, uint8_t Value);
// === GLOBALS ===
tHandler gCoke_Handler = {
const char *gsCoke_ModbusAddress = "130.95.13.73";
modbus_t *gCoke_Modbus;
time_t gtCoke_LastDispenseTime;
+time_t gtCoke_LastReconnectTime;
int gbCoke_DummyMode = 1;
+ int giCoke_NextCokeSlot = 0;
// == CODE ===
int Coke_InitHandler()
{
- printf("Connecting to coke machine on '%s'\n", gsCoke_ModbusAddress);
-
// Configuable dummy/blank mode (all dispenses succeed)
// TODO: Find a better way of handling missing/invalid options
if( Config_GetValueCount("coke_dummy_mode") > 0 )
}
// Open modbus
- modbus_new_tcp(gsCoke_ModbusAddress, 502);
- if( !gCoke_Modbus )
- {
- perror("coke - modbus_new_tcp");
- }
- else
+ if( !gbCoke_DummyMode )
{
- if( modbus_connect(gCoke_Modbus) )
- {
- perror("coke - modbus_connect");
- }
+ Coke_int_ConnectToPLC();
}
return 0;
int Coke_CanDispense(int UNUSED(User), int Item)
{
- uint8_t status;
- // Sanity please
- if( Item < 0 || Item > 6 ) return -1;
-
+ int slot;
+
// Check for 'dummy' mode
if( gbCoke_DummyMode )
return 0;
-
- // Can't dispense if the machine is not connected
- if( !gCoke_Modbus )
- return -2;
- modbus_read_bits(gCoke_Modbus, ciCoke_StatusBitBase + Item, 1, &status);
+ // Get slot
+ slot = Coke_int_GetSlotFromItem(Item, 0);
+ if(slot < 0) return -1;
- return status == 0;
+ return Coke_int_IsSlotEmpty(slot);
}
/**
*/
int Coke_DoDispense(int UNUSED(User), int Item)
{
- // Sanity please
- if( Item < 0 || Item > 6 ) return -1;
-
+ int slot;
// Check for 'dummy' mode
if( gbCoke_DummyMode )
return 0;
-
- // Can't dispense if the machine is not connected
- if( !gCoke_Modbus )
- return -2;
+ // Get slot
+ slot = Coke_int_GetSlotFromItem(Item, 1);
+ if(slot < 0) return -1;
+
// Make sure there are not two dispenses within n seconds
if( time(NULL) - gtCoke_LastDispenseTime < ciCoke_MinPeriod )
{
int delay = ciCoke_MinPeriod - (time(NULL) - gtCoke_LastDispenseTime);
- printf("Wait %i seconds?\n", delay);
+ Debug_Debug("Waiting for %i seconds (rate limit)", delay);
sleep( delay );
- printf("wait done\n");
+ Debug_Debug("wait done");
}
+ gtCoke_LastDispenseTime = time(NULL);
+
+ return Coke_int_DropSlot(slot);
+}
+
+// --- INTERNAL FUNCTIONS ---
+int Coke_int_ConnectToPLC(void)
+{
+ // Ratelimit
+ if( time(NULL) - gtCoke_LastReconnectTime < COKE_RECONNECT_RATELIMIT )
+ return -1;
+
+ if( !gCoke_Modbus )
+ {
+ gCoke_Modbus = modbus_new_tcp(gsCoke_ModbusAddress, 502);
+ if( !gCoke_Modbus )
+ {
+ perror("coke - modbus_new_tcp");
+ gtCoke_LastReconnectTime = time(NULL);
+ return 1;
+ }
+ }
+ else {
+ // Preven resource leaks
+ modbus_close(gCoke_Modbus);
+ }
+ Debug_Notice("Connecting to coke PLC machine on '%s'\n", gsCoke_ModbusAddress);
- // Dispense (with locking)
- modbus_write_bit(gCoke_Modbus, ciCoke_DropBitBase + Item, 1);
+ if( modbus_connect(gCoke_Modbus) )
+ {
+ gtCoke_LastReconnectTime = time(NULL);
+ perror("coke - modbus_connect");
+ modbus_free(gCoke_Modbus);
+ gCoke_Modbus = NULL;
+ return 1;
+ }
+
+ return 0;
+}
+
+int Coke_int_GetSlotFromItem(int Item, int bDispensing)
+{
+ if( Item < 0 || Item > 6 ) return -1;
+
+ // Non-coke slots
+ if( Item < 6 )
+ return Item;
+
+ // Iterate though coke slots and find the first one with a drink avaliable
+ // `giCoke_NextCokeSlot` ensures that the slots rotate
+ for( int i = 0; i < 4; i ++ )
+ {
+ int slot = 6 + (i + giCoke_NextCokeSlot) % 4;
+ if( !Coke_int_IsSlotEmpty(slot) )
+ {
+ if(bDispensing) {
+ giCoke_NextCokeSlot ++;
+ if(giCoke_NextCokeSlot == 4) giCoke_NextCokeSlot = 0;
+ }
+ return slot; // Drink avaliable
+ }
+ }
+
+ // Coke is empty!
+ // - Return 6, even if it's empty, the checks elsewhere will avoid problems
+ return 6;
+}
+
+int Coke_int_IsSlotEmpty(int Slot)
+{
+ uint8_t status;
+
+ if( Slot < 0 || Slot > 9 ) return -1;
+
+ errno = 0;
+ if( _ReadBit(ciCoke_StatusBitBase + Slot, &status) )
+ {
+ perror("Coke_int_IsSlotEmpty - modbus_read_bits");
+ return -2;
+ }
+
+ return status == 0;
+}
+
+int Coke_int_DropSlot(int Slot)
+{
+ uint8_t res;
+
+ if(Slot < 0 || Slot > 9) return -1;
+
+ // Check if a dispense is in progress
+ if( _ReadBit(ciCoke_DropBitBase + Slot, &res) )
+ {
+ perror("Coke_int_DropSlot - modbus_read_bits#1");
+ return -2;
+ }
+ if( res != 0 )
+ {
+ // Manual dispense in progress
+ return -1;
+ }
+
+ // Dispense
+ if( _WriteBit(ciCoke_DropBitBase + Slot, 1) )
+ {
+ perror("Coke_int_DropSlot - modbus_write_bit");
+ return -2;
+ }
+
+ // Check that it started
+ usleep(1000); // 1ms
+ if( _ReadBit(ciCoke_DropBitBase + Slot, &res) )
+ {
+ perror("Coke_int_DropSlot - modbus_read_bits#2");
+ return -2;
+ }
+ if( res == 0 )
+ {
+ // Oops!, no drink
+ Log_Error("Drink dispense failed, bit lowered too quickly");
+ Debug_Notice("Drink dispense failed, bit lowered too quickly");
+ return 1;
+ }
return 0;
}
+int _ReadBit(int BitNum, uint8_t *Value)
+{
+ errno = 0;
+ if( !gCoke_Modbus && Coke_int_ConnectToPLC() )
+ return -1;
+ if( modbus_read_bits( gCoke_Modbus, BitNum, 1, Value) >= 0 )
+ return 0;
+ if( Coke_int_ConnectToPLC() )
+ return -1;
+ if( modbus_read_bits( gCoke_Modbus, BitNum, 1, Value) >= 0 )
+ return 0;
+ return -1;
+}
+
+int _WriteBit(int BitNum, uint8_t Value)
+{
+ errno = 0;
+ if( !gCoke_Modbus && Coke_int_ConnectToPLC() )
+ return -1;
+ if( modbus_write_bit( gCoke_Modbus, BitNum, Value != 0 ) >= 0 )
+ return 0;
+ // Error case
+ if( Coke_int_ConnectToPLC() )
+ return -1;
+ if( modbus_write_bit( gCoke_Modbus, BitNum, Value != 0 ) >= 0 )
+ return 0;
+ return -1;
+}
+