CODEWITHSUNDEEP
c++serial-portptyvirtual-serial-port
critikull
critikull

Reputation: 11

C++ - Testing serial ports without a physical device

I have a program that splits a serial device into multiple virtual serial ports and routes all the data to them.

                    ---- /dev/ttyS1.a [data]->
                    |
[data]-> /dev/ttyS1 ---- /dev/ttyS1.b [data]->
                    |
                    ---- /dev/ttyS1.c [data]->

My working program (pseudo code for sake of readability and simplicity):

poll(...) {
    // Route data from master to vsp
    master.read(buf)
    for(virtual serial ports as vsp) {
        vsp.write(buf)
    }
    // Route data from vsp to master (if need be)
    for(virtual serial ports as vsp) {
        if(vsp.needs_to_write()) {
            vsp.read(buf)
            master.write(buf)
        }
    }
}

I have one physical serial port device on my machine that continuously feeds data through, which is how I tested if my program initially works, but I would like to write a test to emulate/simulate writing and reading both directions and verifying the data on both ends. Since the data I am receiving from my physical serial port device writes seemingly random data it is hard to verify what is going in is exactly what is being written.

How would I be able to do this? (pseudo code)

1. fork process that feeds a known char sequence into /dev/ttyS2 in a loop
2. use my program to read from the COM `master.read(buf)` and then write to the vsp `vsp.write(buf)`
3. how can I verify that after writing to the buf that the vsp has the correct data?

Any help is appreciated I am confused on how to automate testing this.

Edit 1: No one can help?

Upvotes: 1

Views: 1097

Answers (1)

user38723
user38723

Reputation: 39

I think you can use com0com to test. You can connect virtual serial ports and then write to one and read from other what it received. enter link description here

Upvotes: 0

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