RS 232 programming?
Author
Hello, I have been working on a vending machine application for the last 18 months and it is now finished although I have a few loose ends to tie up. The biggest of these is that I now have to interface with a coin acceptor through an RS232 port(via a USB->Serial card). I have never done any serial port programming before and I don't really know what I am doing.
Here is all I know.
1. The coin acceptor has a 17 pin connector on, of which only 16 are present.
2. This connects to the USB->Serial controller that I have which is installed on my machine.
I need two things really,
1. What do I need to know from the manfacturer about the various pins?
2. Could anybody point me in the direction of a good turorial, or just give me a brief overview to get me started?
Thanks in advance for any help.
Mark
If the coin acceptor is a peripheral device then you will need to know what information it sends back to, you will need to know the interface. If it is simple enough then you could probably just open a port and just sit back waiting for data to come in.
This is some code i wrote for an assignment at uni, it is a chat client that sits on a RS232 COM serial port. If you can rip it apart you will see how com operations works.
ace
This is some code i wrote for an assignment at uni, it is a chat client that sits on a RS232 COM serial port. If you can rip it apart you will see how com operations works.
#include <stdio.h>#include <sys/types.h>#include <conio.h>#include <ctype.h>#include <windows.h>#include <winbase.h>char LocalUserID;char OnlineUserArray[26];// Some global flags to keep track of various non-state operationsbool PacketToSend = false;bool LocalUserLoggedIn = false;bool SendLoggedInMessage = false;bool SendLogInAcknowledgement = false;bool SendLoggedOutMessage = false;bool SendDataMessage = false;bool SendMessageAcknowledgement = false;bool SendGenericPacket = false;bool DisplayFullPacketContents = false;bool ExtendedMessaging = false;HANDLE hComPort;DWORD dwError;char RecipientOfAck;char RecipientOfNextMsg;char MessageToSendArray[10];// A buffer of 10 DPacket copieschar LastDPacketSent[10][16];// Define some global states and a state tracking variable//KeyBoard States#define KEYLOGGEDIN 1#define KEYLOGGEDOUT 2//Transmit States#define TRANSMITTING 1#define NOTTRANSMITTING 2//Recieve States#define RECIEVING 1#define NOTRECIEVING 2int KeyBoardStateTracker = KEYLOGGEDOUT;int TransmitStateTracker = TRANSMITTING;int RecieveStateTracker = RECIEVING;bool DrawOnMenu = true;bool DrawOffMenu = true;char InPacket[16];char OutPacket[16];int iPacketArrayMember;int InitiatePort(char *device){ COMMTIMEOUTS noblock; DCB dcb; int fSuccess; hComPort=CreateFile(device,GENERIC_READ | GENERIC_WRITE,0,NULL,OPEN_EXISTING,0,NULL); if (hComPort == INVALID_HANDLE_VALUE) { dwError = GetLastError(); printf("INVALID_HANDLE_VALUE()"); } fSuccess = GetCommTimeouts(hComPort, &noblock); noblock.ReadTotalTimeoutConstant = 1; noblock.ReadTotalTimeoutMultiplier = MAXDWORD; noblock.ReadIntervalTimeout = MAXDWORD; fSuccess=SetCommTimeouts(hComPort,&noblock); fSuccess = GetCommState(hComPort, &dcb); if(!fSuccess) { printf("GetCommState Error!\n"); } dcb.BaudRate = 9600; dcb.ByteSize = 7; dcb.fParity = TRUE; dcb.Parity = EVENPARITY; dcb.StopBits = TWOSTOPBITS; dcb.fRtsControl = RTS_CONTROL_HANDSHAKE; dcb.fOutxCtsFlow = TRUE; fSuccess = SetCommState(hComPort, &dcb); if(!fSuccess) { printf("SetCommState Error!\n"); } return 1;}int ClearPacketArrays(){ for (int count = 0; count < 17; count++) { InPacket[count] = ' '; OutPacket[count] = ' '; } return 1;}int ReadCom(){ char item; unsigned long ni; BOOL fsuccess; fsuccess = ReadFile(hComPort,&item,1,&ni,NULL); if (ni == 1) return item; else return 0;}void DisplayMessageFromPacket(){ printf("\n%c Says : ", InPacket[2]); if (DisplayFullPacketContents == true) { for (int i = 0; i < 16; i++) { printf("%c", InPacket); } } else for (int i = 4; i < 14; i++) { printf("%c", InPacket); } printf("\n");}void DisassemblePacket(){ if ( InPacket[3] == 'L') { if (LocalUserLoggedIn == true) { if (ExtendedMessaging == true) DisplayMessageFromPacket(); if (InPacket[1] == LocalUserID) { } else { int converted; // convert to ascii value converted = (int) toupper(InPacket[1]); // Fill user log in table for appropriate user OnlineUserArray[(converted-65)] = InPacket[1]; SendLogInAcknowledgement = true; } } } else if( InPacket[3] == 'R') { if (LocalUserLoggedIn == true) { if (ExtendedMessaging == true) DisplayMessageFromPacket(); if (InPacket[1] == LocalUserID) { } else { int converted; // convert to ascii value converted = (int) toupper(InPacket[1]); // Fill user log in table for appropriate user OnlineUserArray[(converted-65)] = InPacket[2]; } } } else if( InPacket[3] == 'X') { if (LocalUserLoggedIn == true) { if (ExtendedMessaging == true) DisplayMessageFromPacket(); if (InPacket[1] != LocalUserID) { int converted; // convert to ascii value converted = (int) toupper(InPacket[1]); // Fill user log in table for appropriate user OnlineUserArray[(converted-65)] = '_'; } } } else if( InPacket[3] == 'D') { if (LocalUserLoggedIn == true) { // Check to see if i'm the recipient if (InPacket[1] == LocalUserID) { // Data payload packet ie a message to be displayed to the screen // Then send an acknowledgement packet to the author DisplayMessageFromPacket(); // Set the global variable that will hold the recipient of the acknowledgemnt packet RecipientOfAck = InPacket[2]; SendMessageAcknowledgement = true; } else { // Construct a copy of the recieved packet to forward on OutPacket[0] = '{'; OutPacket[1] = InPacket[1]; OutPacket[2] = InPacket[2]; OutPacket[3] = InPacket[3]; OutPacket[4] = InPacket[4]; OutPacket[5] = InPacket[5]; OutPacket[6] = InPacket[6]; OutPacket[7] = InPacket[7]; OutPacket[8] = InPacket[8]; OutPacket[9] = InPacket[9]; OutPacket[10] = InPacket[10]; OutPacket[11] = InPacket[11]; OutPacket[12] = InPacket[12]; OutPacket[13] = InPacket[13]; OutPacket[14] = InPacket[14]; OutPacket[15] = '}'; // Tell the transmitting loop to send it on SendGenericPacket = true; } } }}bool DealWithRecievedCharacter(char iInCharacter, bool *RunFlag){ if (iInCharacter != 0) { if (iInCharacter == '{') { iPacketArrayMember = 0; InPacket[iPacketArrayMember] = iInCharacter; iPacketArrayMember++; } else { InPacket[iPacketArrayMember] = iInCharacter; iPacketArrayMember++; if (iInCharacter == '}') return true; } } else { } return false;}int CompilePacketToSend(char PacketType){ if (PacketType == 'L') { OutPacket[0] = '{'; OutPacket[1] = LocalUserID; OutPacket[2] = LocalUserID; OutPacket[3] = PacketType; OutPacket[4] = '*'; OutPacket[5] = 'O'; OutPacket[6] = 'n'; OutPacket[7] = 'l'; OutPacket[8] = 'i'; OutPacket[9] = 'n'; OutPacket[10] = 'e'; OutPacket[11] = ' '; OutPacket[12] = ' '; OutPacket[13] = ' '; OutPacket[14] = '#'; OutPacket[15] = '}'; } else if (PacketType == 'X') { OutPacket[0] = '{'; OutPacket[1] = LocalUserID; OutPacket[2] = LocalUserID; OutPacket[3] = PacketType; OutPacket[4] = '*'; OutPacket[5] = 'O'; OutPacket[6] = 'f'; OutPacket[7] = 'f'; OutPacket[8] = 'l'; OutPacket[9] = 'i'; OutPacket[10] = 'n'; OutPacket[11] = 'e'; OutPacket[12] = ' '; OutPacket[13] = ' '; OutPacket[14] = '#'; OutPacket[15] = '}'; } else if (PacketType == 'R') { OutPacket[0] = '{'; OutPacket[1] = RecipientOfNextMsg; OutPacket[2] = LocalUserID; OutPacket[3] = PacketType; OutPacket[4] = 'L'; OutPacket[5] = 'o'; OutPacket[6] = 'g'; OutPacket[7] = 'i'; OutPacket[8] = 'n'; OutPacket[9] = ' '; OutPacket[10] = 'A'; OutPacket[11] = 'c'; OutPacket[12] = 'k'; OutPacket[13] = ' '; OutPacket[14] = '#'; OutPacket[15] = '}'; } else if (PacketType == 'D') { OutPacket[0] = '{'; OutPacket[1] = RecipientOfNextMsg; OutPacket[2] = LocalUserID; OutPacket[3] = PacketType; OutPacket[4] = MessageToSendArray[0]; OutPacket[5] = MessageToSendArray[1]; OutPacket[6] = MessageToSendArray[2]; OutPacket[7] = MessageToSendArray[3]; OutPacket[8] = MessageToSendArray[4]; OutPacket[9] = MessageToSendArray[5]; OutPacket[10] = MessageToSendArray[6]; OutPacket[11] = MessageToSendArray[7]; OutPacket[12] = MessageToSendArray[8]; OutPacket[13] = MessageToSendArray[9]; OutPacket[14] = '#'; OutPacket[15] = '}'; } else if (PacketType == 'Y') { OutPacket[0] = '{'; OutPacket[1] = InPacket[2]; OutPacket[2] = LocalUserID; OutPacket[3] = PacketType; OutPacket[4] = '+'; OutPacket[5] = ' '; OutPacket[6] = 'A'; OutPacket[7] = 'C'; OutPacket[8] = 'K'; OutPacket[9] = ' '; OutPacket[10] = ' '; OutPacket[11] = ' '; OutPacket[12] = ' '; OutPacket[13] = ' '; OutPacket[14] = '#'; OutPacket[15] = '}'; } else if (PacketType == 'N') { OutPacket[0] = '{'; OutPacket[1] = RecipientOfNextMsg; OutPacket[2] = LocalUserID; OutPacket[3] = PacketType; OutPacket[4] = '-'; OutPacket[5] = ' '; OutPacket[6] = 'A'; OutPacket[7] = 'C'; OutPacket[8] = 'K'; OutPacket[9] = ' '; OutPacket[10] = ' '; OutPacket[11] = ' '; OutPacket[12] = ' '; OutPacket[13] = ' '; OutPacket[14] = '#'; OutPacket[15] = '}'; } return 1;}int SendPacket(){ unsigned long ni; BOOL fSuccess; fSuccess = WriteFile(hComPort,OutPacket,16,&ni,NULL); if (ni == 16 ) return 0; else return 1;}void LogIn(){}void LogOut(bool *pRunFlag){ int converted; converted = (int) LocalUserID; OnlineUserArray[(converted-65)] = 1; LocalUserID = ' '; PacketToSend = false; LocalUserLoggedIn = false; SendLoggedInMessage = true; SendLogInAcknowledgement = false; KeyBoardStateTracker = KEYLOGGEDOUT;} //void GeneralInitiationvoid menuLoggedOut(){ system("cls"); printf("\t=======================================\n"); printf("\t====== Not Logged In ======\n"); printf("\t=======================================\n"); printf("\t=======================================\n"); printf("\t 1. Log In\n"); printf("\n"); printf("\t 2. Exit\n"); printf("\n"); printf("\n"); printf("\t Enter Choice: ");}void menuLoggedIn(){ system("cls"); printf("\t=======================================\n"); printf("\t====== Logged in as %c ======\n", LocalUserID); printf("\t=======================================\n"); printf("\t=======================================\n"); printf("\t 1. Log Out\n"); printf("\n"); printf("\t 2. SendMessage\n"); printf("\n"); printf("\t 3. View Online Contacts\n"); printf("\n"); printf("\t 4. Display Full Packet Contents -"); if (DisplayFullPacketContents == true) { printf(" ON\n"); } else { printf(" OFF\n"); } printf("\n"); printf("\t 5. Use Extended Messaging -"); if (ExtendedMessaging == true) { printf(" ON\n"); } else { printf(" OFF\n"); } printf("\n"); printf("\t 6. Exit\n"); printf("\n"); printf("\n"); printf("\t Enter Choice: ");}int main(){ int hr; char CharacterRead; bool RunFlag = 1; bool *pRunFlag = &RunFlag; for (int i = 0; i < 16; i++) { MessageToSendArray = 'B'; } for (i = 0; i < 26; i++) { OnlineUserArray = '_'; } // When the app starts no user will be logged in if ( ( hr = InitiatePort("COM1") ) == 0 ) { printf("Initialising The Port FAILED!\n"); } else { printf("Initialising The Port SUCCEEDED!\n"); } printf("Clearing Packet Arrays...\n"); if ( ( hr = ClearPacketArrays() )== 0 ) { printf("Clearing Packet Arrays FAILED!\n"); } else { printf("Clearing Packet Arrays SUCCEEDED!\n"); } // Draw menu menuLoggedOut(); while(RunFlag) { //KEYBOARD switch (KeyBoardStateTracker) { case KEYLOGGEDOUT: //If not logged in locally just track network users and pass on packets { // Check of user logging in if ( kbhit() ) { // Allocate memory for user selection char CharacterRead; while ( ( CharacterRead = getchar() ) == '\n' ) { menuLoggedOut(); } if (CharacterRead == '1') { //printf("Log In Here: "); while ( ( CharacterRead = getchar() ) == '\n') { menuLoggedOut(); printf("\n\n\t Log In Here: "); } int converted; // convert to ascii value converted = (int) toupper(CharacterRead); // Declare that im logged on in my log table OnlineUserArray[(converted-65)] = toupper(CharacterRead); // Establish that im logged in LocalUserLoggedIn = true; // Set Local User ID to newly signed in user LocalUserID = toupper(CharacterRead); // Switch to log in routines KeyBoardStateTracker = KEYLOGGEDIN; // Display the logged in menu menuLoggedIn(); // Dont send again SendLoggedInMessage = true; } else if (CharacterRead == '2') { RunFlag = 0; } } break; } case KEYLOGGEDIN: { if ( kbhit() ) { // Allocate memory for user selection char CharacterRead; while ( ( CharacterRead = getchar() ) == '\n' ) { menuLoggedIn(); } if (CharacterRead == '1') { int ConvertedValue; // convert to ascii value ConvertedValue = (int) toupper(LocalUserID); // Declare that im logged on in my log table OnlineUserArray[(ConvertedValue-65)] = 0; // Establish that im logged in LocalUserLoggedIn = false; // Switch to log out routines KeyBoardStateTracker = KEYLOGGEDOUT; // Tell the transmitter to send a logged out packet SendLoggedOutMessage = true; // Display the logged out menu menuLoggedOut(); } else if (CharacterRead == '2') { int ItemInMessageArray = 0; printf("\n\n\t Recipient ID: "); while ( ( CharacterRead = getchar() ) == '\n' ) { menuLoggedIn(); printf("\n\n\t Recipient ID: "); } RecipientOfNextMsg = CharacterRead; RecipientOfNextMsg = toupper(RecipientOfNextMsg); printf("\n\t 10 Char Message: "); for (ItemInMessageArray; ItemInMessageArray < 10; ItemInMessageArray++) { while ( ( CharacterRead = getchar() ) == '\n' ) { menuLoggedIn(); printf("\n\n\t Recipient ID: %c", RecipientOfNextMsg); printf("\n\t 10 Char Message: "); } MessageToSendArray[ItemInMessageArray] = CharacterRead; } SendDataMessage = true; menuLoggedIn(); } else if (CharacterRead == '3') { printf("\nOnline Contacts: "); for (i = 0; i <26; i++) { //if (OnlineUserArray != '0') //{ printf("%c", OnlineUserArray); //} } } else if (CharacterRead == '4') { if (DisplayFullPacketContents == true) DisplayFullPacketContents = false; else DisplayFullPacketContents = true; menuLoggedIn(); } else if (CharacterRead == '5') { if (ExtendedMessaging == true) ExtendedMessaging = false; else ExtendedMessaging = true; menuLoggedIn(); } else if (CharacterRead == '6') { RunFlag = 0; int ConvertedValue; // convert to ascii value ConvertedValue = (int) toupper(LocalUserID); // Declare that im logged on in my log table OnlineUserArray[(ConvertedValue-65)] = 0; // Establish that im logged in LocalUserLoggedIn = false; // Switch to log out routines KeyBoardStateTracker = KEYLOGGEDOUT; // Tell the transmitter to send a logged out packet SendLoggedOutMessage = true; // Display the logged out menu menuLoggedOut(); } } } } switch (TransmitStateTracker) { case TRANSMITTING: { if (LocalUserLoggedIn == true) { if (SendLoggedInMessage == true) { // Pass the packet type of L to create a log in packet CompilePacketToSend('L'); // Transmitt the log in packet SendPacket(); SendLoggedInMessage = false; } else if (SendLogInAcknowledgement == true) { // Send Aknowledgement packet back to sender only if the // sender isnt myself DO THIS BIT LATER CompilePacketToSend('R'); SendPacket(); SendLogInAcknowledgement = false; } else if (SendMessageAcknowledgement == true) { CompilePacketToSend('Y'); SendPacket(); SendMessageAcknowledgement = false; } else if (SendDataMessage == true) { CompilePacketToSend('D'); SendPacket(); SendDataMessage = false; } else if (SendGenericPacket == true) { SendPacket(); SendGenericPacket = false; } } if (SendLoggedOutMessage == true) { CompilePacketToSend('X'); SendPacket(); SendLoggedOutMessage = false; } break; } case NOTTRANSMITTING: { } } switch (RecieveStateTracker) { case RECIEVING: { bool bResult; CharacterRead = ReadCom(); bResult = DealWithRecievedCharacter(CharacterRead, pRunFlag); if (bResult == true) { DisassemblePacket(); } break; } case NOTRECIEVING: { } } } return 0;}ace
Another thread on GameDev on the topic of RS232: RS232 Interface?
Not sure if it'll be of any help, but I thought I'd link it.
Not sure if it'll be of any help, but I thought I'd link it.
Author
Ok, I have read lots about serial comms now and a couple of questions arise.
1. Most of the sources I have seen talk about 22/15/9 way connectors, but I have a 17?
2. All sources deal with sending characters to/from the port. In this application it would appear that rather than sending characters I have to read/write the states of individual pins.
If any one has time, the pin assignments are on page 12 of this file:
http://www.namco.co.uk/Namco%20new/Page%204/PDF/MARS%20Manuals/126&129_User_Guide.pdf
If anyone knows how to insert this table here, I would be extremely appreciative.
Thanks for any help on this one.
Mark
1. Most of the sources I have seen talk about 22/15/9 way connectors, but I have a 17?
2. All sources deal with sending characters to/from the port. In this application it would appear that rather than sending characters I have to read/write the states of individual pins.
If any one has time, the pin assignments are on page 12 of this file:
http://www.namco.co.uk/Namco%20new/Page%204/PDF/MARS%20Manuals/126&129_User_Guide.pdf
If anyone knows how to insert this table here, I would be extremely appreciative.
Thanks for any help on this one.
Mark
Author
Ok, turns out I was wrong, there is simple instruction set for talking to the interface card. Bingo!
Cheers for the code, Ace, it was a HUGE help. The MSDN docs are not so good.
Mark
Cheers for the code, Ace, it was a HUGE help. The MSDN docs are not so good.
Mark
This topic is closed to new replies.
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