Wizlora 100 com port issue


I have a Wiz lora 100 device, I’m trying to interface w7500 with it so that I can send sensor data as well as AT commands from w7500, The issue I’m facing is that
1)The device is not displayed in my com port and I get Serial port COM 28 opening error any help as to why this happens.

  1. When I try to send AT commands from w7500 the reply I get is T and R characters, and not OK… Am I doing something wrong…
    #include “mbed.h”

Serial pc(USBTX, USBRX);
//Serial a(D15,D14);
//Serial a(PA_13,PA_14);
Serial a (D1,D0);
int port=10;
int port1=11;
DigitalIn ip(D3);
char b[20];
int main()

{ a.baud(115200);
int c;
while(1) {
c = ip.read();
// char data=‘h’;
pc.printf(“PIR Value : %d\r\n”,c);
a.gets((char *)b,2);

   // a.printf("AT+LSEND=");

// a.printf("%d",port);
// a.printf(",");
// a.printf("%d",c);
// pc.printf(“done\r\n”);
The output