90% this are definitions for forms, buttons, menus and Alerts. "appFileCreator" needs some attions, because this is an ID, wich identifies your application and must not be identical to other "appFileCreator"-IDs, otherwise it can lead to data loss. There was a service from Palm, which make sure, that there was only one unique ID for each application. Of course this service is not online anymore. So today is pure luck if it is working with other applications or not.
Resources-File
This is the resources-File of the application
GENERATEHEADER "serialcomm_Rsc.h"
#include "serialcomm.h"
FORM ID MainForm AT (0 0 160 160)
MENUID MainMenu
BEGIN
TITLE "Serial Comm. with Palm OS"
LABEL "Send a predefined String:" AUTOID AT (CENTER 20) FONT 1
BUTTON "Send" ID PredefinedStringButton AT (CENTER 35 AUTO AUTO) FONT 0
LABEL "Send a custom String:" AUTOID AT (CENTER 100) FONT 1
FIELD ID CustomStringField AT (CENTER PREVBOTTOM+8 110 AUTO) FONT 0 UNDERLINED MAXCHARS 23
BUTTON "Send" ID CustomStringButton AT (CENTER 140 AUTO AUTO) FONT 0
FRAME
FRAME
LABEL "Send predefined hex-values:" AUTOID AT (CENTER 55) FONT 1
BUTTON "41 42 43 44 45 46 47 48 49 4A" ID PredefinedHexButton AT (CENTER 75 AUTO AUTO) FONT 0
END
ALERT ID HelpAlert
INFORMATION
BEGIN
TITLE "Help"
MESSAGE "Help is available at\n"\
"https://palm2000.de/\n"\
"projects/\n"\
"serialCommunication\nWithPalmOsPart1.php"
BUTTONS "OK"
END
ALERT ID AboutApplicationAlert
INFORMATION
BEGIN
TITLE "Serial Comm. with Palm OS"
MESSAGE "This is a small demo-application in order to send some data over the serial interface of a Palm PDA.\n"
BUTTONS "OK"
END
ALERT ID OsVersionTooLowAlert
ERROR
BEGIN
TITLE "Palm OS Version too low!"
MESSAGE "Palm OS 2.0 or greater is required in order to run this application."
BUTTONS "OK"
END
MENU ID MainMenu
BEGIN
PULLDOWN "Options"
BEGIN
MENUITEM "Help" ID MainOptionsHelpCmd "H"
MENUITEM SEPARATOR
MENUITEM "About this application" ID MainOptionsAboutCmd "A"
END
END
ALERT ID ErrorOccurredAlert
ERROR
BEGIN
TITLE "An error occurred!"
MESSAGE "^1\n^2\n^3"
BUTTONS "OK"
END
VERSION 1 "0.0.1"
LAUNCHERCATEGORY ID 1000 "Utilities"
ICON "serialcomm_22.bmp"
SMALLICON "serialcomm_9.bmp"
Here are all UI-elements are defined and their parameters like titles and locations.
c-File
This is the c-File with all the code, which contains the "business-logic" of the application.
#include "serialcomm.h"
#include <UI/UIPublic.h>
#include <System/SystemPublic.h>
#include <PalmCompatibility.h>
#include <PalmTypes.h>
// Here is the used baudrate defined. It is very important that this value matches the baudrate of the server-application
#define BAUDRATE 9600
UInt16 comPort = 0;
static Char* GetFromInputField(UInt16, UInt16);
static void SendDataSerial(void*);
// This function fetches the input from the "CustomStringField" and returns it
static Char* GetFromInputField(UInt16 formID, UInt16 fieldID)
{
FormPtr formPtr;
FieldPtr fieldPtr;
UInt16 objectIndex;
formPtr = FrmGetFormPtr(formID);
objectIndex = FrmGetObjectIndex(formPtr, fieldID);
fieldPtr = (FieldPtr)FrmGetObjectPtr(formPtr, objectIndex);
return FldGetTextPtr(fieldPtr);
}
// This is the function with the business-logic
static Boolean MainFormHandleEvent(EventType *event)
{
//char hexVar[10] = {0x7E,0xFF,0x06,0x09,0x00,0x00,0x04,0x44,0xDD,0xEF};
Boolean handled = false;
Err err;
char *custStrFieldInputPtr;
// This is the prefined hex-codes and the predefined char-array
char hexVar[10] = {0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4A};
char preDefStr[31] = "A text from a Palm OS device.\0";
char (*hexVarPtr)[10];
char (*preDefStrPtr)[31];
hexVarPtr = &hexVar;
preDefStrPtr = &preDefStr;
if(event->eType == frmOpenEvent) {
FrmDrawForm(FrmGetActiveForm());
handled = true;
}
if(event->eType == ctlSelectEvent) {
switch (event->data.ctlSelect.controlID)
{
case PredefinedHexButton:
// For sending hex-data, a light modification of the SendDataSerial-funciton is need, this is why the code is sperate
SrmReceiveFlush(comPort, 0);
SrmSend(comPort, hexVarPtr, 11, &err);
// The "\n"-char gives the command to acutally send the data
SrmSend(comPort, "\n", 1, &err);
break;
case PredefinedStringButton:
SendDataSerial(preDefStrPtr);
break;
case CustomStringButton:
custStrFieldInputPtr = GetFromInputField(MainForm,CustomStringField);
// This avoid problems, when the input-field is empty and the user hits "send"
if(!custStrFieldInputPtr) {
SendDataSerial("NULL");
}else{
SendDataSerial(custStrFieldInputPtr);
}
break;
default:
break;
}
}
return handled;
}
// This function sends text over the serial-interface
static void SendDataSerial(void* value){
Err err;
SrmReceiveFlush(comPort, 0);
SrmSend(comPort, value, StrLen(value), &err);
SrmSend(comPort, "\n", 1, &err);
}
static Boolean AppHandleEvent(EventPtr event)
{
FormType* formTypePtr;
UInt16 formId;
Boolean handled = false;
if (event->eType == frmLoadEvent)
{
formId = event->data.frmLoad.formID;
formTypePtr = FrmInitForm(formId);
FrmSetActiveForm(formTypePtr);
switch (formId)
{
case MainForm:
FrmSetEventHandler(formTypePtr, MainFormHandleEvent);
break;
default:
break;
}
return true;
}
if (event->eType == menuEvent)
{
MenuEraseStatus(NULL);
switch (event->data.menu.itemID)
{
case MainOptionsHelpCmd:
FrmAlert(HelpAlert);
handled = true;
break;
case MainOptionsAboutCmd:
FrmAlert(AboutApplicationAlert);
handled = true;
break;
default:
break;
}
return true;
}
return false;
}
static void AppEventLoop(void)
{
EventType event;
Err error;
do
{
EvtGetEvent(&event, evtWaitForever);
if (SysHandleEvent(&event)) {
continue;
}
if (MenuHandleEvent((void *)0, &event, &error)) {
continue;
}
if (AppHandleEvent(&event)) {
continue;
}
FrmDispatchEvent(&event);
}
while (event.eType != appStopEvent);
}
static Err stopApplication()
{
Err returnCode;
FrmCloseAllForms();
returnCode = SrmClose(comPort);
return returnCode;
}
static Err startApplication()
{
Err returnCode = 0;
returnCode = SrmOpen(serPortCradlePort, BAUDRATE, &comPort);
if ( returnCode == 0) {
FrmGotoForm(MainForm);
}
return returnCode;
}
UInt32 PilotMain(UInt16 cmd, MemPtr cmdPBP, UInt16 launchFlags)
{
UInt32 currentRomVersion;
UInt32 requiredRomVersion;
requiredRomVersion = 0x02000000;
FtrGet(sysFtrCreator, sysFtrNumROMVersion, ¤tRomVersion);
if (currentRomVersion < requiredRomVersion)
{
FrmAlert(OsVersionTooLowAlert);
return(sysErrRomIncompatible);
}
if (cmd == sysAppLaunchCmdNormalLaunch)
{
Err returnCode;
returnCode = startApplication();
if (returnCode != 0)
{
ErrAlert(returnCode);
return(returnCode);
}
AppEventLoop();
returnCode = stopApplication();
if (returnCode != 0)
{
ErrAlert(returnCode);
return(returnCode);
}
}
return 0;
}
The complete packaga is downloadable with a proper Makefile HERE. The PRC-file is also available: HERE.
Known problems
This application only works with the old COM port (DE-9 connector). If the application gets started on a devices, which is connected to a USB-cable or -cradle (the USB-cable does not need to be plugged in!), the application crashes with a "Serial: timeout [...] (Ser 0305)"-error-message.
Make always sure the baud rate is configured on all takers (Client/Server, Palm/PC) the same, e.g.: 9600 [bits per second]. Otherwise the transmission will fail.
The application was successfully developed and tested on a Palm m100 and POSE.
