MBed 程序卡住了

Question

I have written some code with the help of Mbed framework, which is either supposed to take user input and then display sensor values or display the value after 15mins. When I try to execute this code, it is getting stuck at line 21 (display.printf("Inside loop\n");).

I am not able to understand why is it so and what is the fix for this problem so that the switch block gets executed. How to I solve this? FYI, although not important, the microcontroller I am using is STM32 bluepill (STM32F103C8T6).

#include "mbed.h"
#include "Sensor_input.h"
#include "Ticker.h"
#include "Dht11.h"

//#include "USBSerial.h"
Serial display(PA_2, PA_3, 9600);
char* a;
Dht11 DhtSensor(PA_4);
Ticker t;
Sensor_input Soil(PB_7, PB_6, 8);
float *SensorData;
void getSensorData();
int main ( void ){

    uint8_t choice = 0;

    display.printf("Enter 1 or 2:\n1.Greenhouse stats\n2.Return Control to System");
    choice = display.putc(display.getc());
    while(1){
        display.printf("Inside loop\n");
        wait_ms(15000);
        switch(choice)
        {
            
            case 1:
                display.printf("Inside case 1");
                a = Soil.readTemp();
                display.printf("Temperature: %f\n",DhtSensor.getCelsius());
                display.printf("Humidity: %f\n",DhtSensor.getHumidity());
                display.printf("Soil water content: %c\n ",*a);
                break;
            case 2:
                /*<GreenHouse object>*/
                /*Might have to proceed with timer*/
                display.printf("Inside case 2");
                t.attach(&getSensorData,4500);
                display.printf("Temperature: %f\n",a[0]);
                display.printf("Humidity: %f\n",a[1]);
                display.printf("Soil water content: %c\n ",a[2]);
                break;
            default:
                break;
            
        }
    }
}
void getSensorData(){
    static float a[3];
    a[0]=DhtSensor.getCelsius();
    a[1]=DhtSensor.getHumidity();
    a[2]=(int)Soil.readTemp();   

}

Answer 1

Your switch statement is probably being executed, but always in the 'default' case. You can test this out by putting a print statement in the default.

When you request a char from the display, it will return the input as an ASCII-character. This means, if you enter '1' on the display, it will give you (as the ASCII table says) 0x31 (decimal 49) and not the value of 1. So you have to change your case to "case '1':" or "case 0x31:" and the equivalent for the second case.