I’m currently working on a Proof of Concept (POC) project using C++ (Qt/QML) on Linux, and I would like to integrate the BACnet Stack with MS/TP support only.
Where do we need to configure Com port and buadrate and how to intialize MS/TP in POC project.
The ultimate goal is to send/receive BACnet services (e.g., Who-Is, I-Am, Who-Has, I-Have) from within a Qt-based application.

Build the BACnet Stack with only MS/TP support (no B/IP, no Ethernet).

Link the BACnet Stack binary (or its compiled object code) into my Qt/QML project.

currentl i have implemented for BACnet IP and Intialization. For reference please check below code :

#include "bacnetintegration.h"
#include <stdlib.h>

#include "QDebug"
static struct mstimer BACnet_Task_Timer;
static struct mstimer BACnet_TSM_Timer;
static struct mstimer BACnet_Address_Timer;
static uint8_t Rx_Buf[MAX_MPDU]; // Buffer for receiving data
bacnet_objects_manager *bac_obj_mgr = bacnet_objects_manager::getInstance();

BacnetIntegration::BacnetIntegration(QObject *parent)
: QObject{parent}
{

timer1 = new QTimer(this);
connect(timer1, SIGNAL(timeout()), this, SLOT(getValue()));
timer1->setInterval(1000);


address_init();
Init_Service_Handlers();
Init_Device();

Init_Communication();

Start_Device();

}

void BacnetIntegration::Init_Device()
{
uint32_t device_instance = 123; // The BACnet device instance number (can be configurable)
Device_Set_Object_Instance_Number(device_instance); // Set the device instance number
Device_Object_Name_ANSI_Init("DeluxeServer"); // Set the device name

BACNET_CREATE_OBJECT_DATA object_data = { 0 };
object_data.object_instance = device_instance;
object_data.object_type = OBJECT_DEVICE;
Device_Init(NULL);  // Initialize the BACnet device object
Device_Create_Object(&object_data);  // Create the device object

// Create and initialize additional objects (e.g., Analog Input, Binary Output)
  // Create Analog Input object with instance 0

bac_obj_mgr->Create_Binary_Output(static_cast<int>(Objects::IDU_ON_OFF));  // screen off/on

bac_obj_mgr->Create_Analog_Value(static_cast<int>(Objects::COOL_TEMPERATURE));   // cool - temperature

bac_obj_mgr->Create_Analog_Value(static_cast<int>(Objects::HEAT_TEMPERATURE));   // Heat - temperature

}

void BacnetIntegration::Init_Service_Handlers()
{
BACNET_CREATE_OBJECT_DATA object_data = { 0 };
unsigned int i = 0;

Device_Init(NULL);

apdu_set_unconfirmed_handler(SERVICE_UNCONFIRMED_WHO_IS, handler_who_is);
apdu_set_unconfirmed_handler(SERVICE_UNCONFIRMED_WHO_HAS, handler_who_has);
apdu_set_confirmed_handler(SERVICE_CONFIRMED_READ_PROPERTY, handler_read_property);
apdu_set_confirmed_handler(SERVICE_CONFIRMED_READ_PROP_MULTIPLE, handler_read_property_multiple_wrapper);

// Add handlers for other services as required...

}

void BacnetIntegration::Init_Communication()
{
dlenv_init(); // Initialize the data link environment
#ifdef BACDL_BIP
qDebug() <<"going to BACDL_BIP" ;
#endif
atexit(datalink_cleanup); // Clean up resources at exit
mstimer_set(&BACnet_Task_Timer, 1000UL); // Timer for periodic tasks
mstimer_set(&BACnet_TSM_Timer, 50UL); // Timer for TSM timeouts
mstimer_set(&BACnet_Address_Timer, 60000UL); // Timer for address binding timeouts
}

void BacnetIntegration::Start_Device()
{
BACNET_ADDRESS src = { 0 };
uint16_t pdu_len = 0;
unsigned timeout = 1; // Milliseconds for datalink receive timeout
uint32_t elapsed_milliseconds = 0;

while (1) {
    pdu_len = datalink_receive(&src, &Rx_Buf[0], MAX_MPDU, timeout);  // Receive data
    if (pdu_len) {
        qDebug() << "[MYDEBUG] not a port issue";
        npdu_handler(&src, &Rx_Buf[0], pdu_len);  // Process the received data
    }

    // Handle periodic tasks (timeouts, status updates, etc.)
    if (mstimer_expired(&BACnet_Task_Timer)) {
        mstimer_reset(&BACnet_Task_Timer);
        elapsed_milliseconds = mstimer_interval(&BACnet_Task_Timer);
        dcc_timer_seconds(elapsed_milliseconds / 1000); // Handle DCC tasks
        // Other periodic tasks...
    }
}

}

void BacnetIntegration::Shutdown_Device()
{
datalink_cleanup();
}

Initialize and use MS/TP communication from my Qt/C++ codebase, invoking Who-Is / I-Am from within the app logic.

Any advice, references, or even simple examples would be very helpful!
Thanks for your amazing work on this stack – it’s been a great learning experience so far. Looking forward to contributing back once I have a working setup!