#include <pthread.h>
#include <unistd.h>
#include <modbus/modbus.h>
+#include <errno.h>
#define MIN_DISPENSE_PERIOD 5
// === 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);
// === GLOBALS ===
tHandler gCoke_Handler = {
modbus_t *gCoke_Modbus;
time_t gtCoke_LastDispenseTime;
int gbCoke_DummyMode = 1;
+ int giCoke_NextCokeSlot = 0;
// == CODE ===
int Coke_InitHandler()
// Open modbus
if( !gbCoke_DummyMode )
{
- printf("Connecting to coke machine on '%s'\n", gsCoke_ModbusAddress);
-
- modbus_new_tcp(gsCoke_ModbusAddress, 502);
- if( !gCoke_Modbus )
- {
- perror("coke - modbus_new_tcp");
- }
-
- if( gCoke_Modbus && modbus_connect(gCoke_Modbus) )
- {
- perror("coke - modbus_connect");
- modbus_free(gCoke_Modbus);
- gCoke_Modbus = NULL;
- }
+ 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;
- if( modbus_read_bits(gCoke_Modbus, ciCoke_StatusBitBase + Item, 1, &status) )
- {
- // TODO: Check for a connection issue
- perror("Coke_CanDispense - modbus_read_bits");
- }
+ // 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 )
{
sleep( delay );
printf("wait done\n");
}
+
+ return Coke_int_DropSlot(slot);
+}
+
+// --- INTERNAL FUNCTIONS ---
+int Coke_int_ConnectToPLC(void)
+{
+ if( !gCoke_Modbus )
+ {
+ gCoke_Modbus = modbus_new_tcp(gsCoke_ModbusAddress, 502);
+ if( !gCoke_Modbus )
+ {
+ perror("coke - modbus_new_tcp");
+ return 1;
+ }
+ }
+ printf("Connecting to coke PLC machine on '%s'\n", gsCoke_ModbusAddress);
+ if( modbus_connect(gCoke_Modbus) )
+ {
+ 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;
+
+ if(!gCoke_Modbus)
+ return -2;
+
+ errno = 0;
+ if( modbus_read_bits(gCoke_Modbus, ciCoke_StatusBitBase + Slot, 1, &status) <= 0 )
+ {
+ // TODO: Retry connection, or fail
+ 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;
+
+ // Can't dispense if the machine is not connected
+ if( !gCoke_Modbus )
+ return -2;
+
+ // Check if a dispense is in progress
+ if( modbus_read_bits(gCoke_Modbus, ciCoke_DropBitBase + Slot, 1, &res) <= 0 )
+ {
+ perror("Coke_int_DropSlot - modbus_read_bits#1");
+ return -2;
+ }
+ if( res != 0 )
+ {
+ // Manual dispense in progress
+ return -1;
+ }
+
// Dispense
- if( modbus_write_bit(gCoke_Modbus, ciCoke_DropBitBase + Item, 1) )
+ if( modbus_write_bit(gCoke_Modbus, ciCoke_DropBitBase + Slot, 1) < 0 )
+ {
+ perror("Coke_int_DropSlot - modbus_write_bit");
+ return -2;
+ }
+
+ // Check that it started
+ usleep(1000); // 1ms
+ if( modbus_read_bits(gCoke_Modbus, ciCoke_DropBitBase + Slot, 1, &res) <= 0 )
+ {
+ perror("Coke_int_DropSlot - modbus_read_bits#2");
+ return -2;
+ }
+ if( res == 0 )
{
- // TODO: Handle connection issues
- perror("Coke_DoDispense - modbus_write_bit");
+ // Oops!, no drink
+ return 1;
}
return 0;