4G module designed by charging pile obtains signal strength and quality

int dx_get_lte_signalQuality(void)
{
    // char cmd[64] = {0};
    //char result[512] = {0};
    int ret = -1;
    char *pcTmp = NULL;
    char sigal[32] = {0};
    char *pcSigal = sigal;
    int rssi = 0;
    int index = 0;
    unsigned char  *cmd = at_tx_buffer;
    unsigned char *result = at_rx_buffer;
    unsigned char result_len = 0;

    // snprintf(cmd, sizeof(cmd), "AT+CSQ");
    memset(at_tx_buffer,0,UART2_TX_BUFFER_LEN);
    memset(at_rx_buffer,0,UART2_RX_BUFFER_LEN);
    snprintf((char*)at_tx_buffer,UART2_TX_BUFFER_LEN, AT_CSQ);
    ret = AT_cmd(cmd, strlen((const char*)cmd), result, &result_len);
    /*
        AT+CSQ
        +CSQ: 19,99

        OK
    */
    //  printf("AT+CSQ:\n%s\n", result);
    printf("\n result =%s\n", result);
    if (ret || !strlen((const char*)result) || !strstr((const char*)result, "OK"))
    {
        ret = 0;
        goto out ;
    }

    pcTmp = strchr((const char*)result, ' ');
    if (pcTmp)
    {
        pcTmp++;
        while(*pcTmp != ',' && *pcTmp >= '0' && *pcTmp <= '9' &&  *pcTmp != '\0')
        {
            *pcSigal++ = *pcTmp++;
        }
    }
    else
    {
        ret = 0;
        goto out ;
    }

    *pcSigal = '\0';
    index = atoi(sigal);
    if (index < 0 || index >= 32)
    {
        ret = 0;
        return 0;
    }

    rssi = -113 + (index * 2);
    printf("index:%d rssi:%d\n", index, rssi);

    if (rssi >= -80)
    {
        // return 4;
        ret =4;
        return ret;
    }
    else if (-90 <= rssi && -80 > rssi)
    {
        // return 3;
        ret =3;
        return ret;
    }
    else if (-105 <= rssi && -90 > rssi)
    {
        //  return 2;
        ret =2;
        return ret;
    }
    else if (-105 > rssi)
    {
        ret =1;
        return ret;
    }
out:
    //	memset(at_tx_buffer,0,UART2_TX_BUFFER_LEN);
    //	memset(at_rx_buffer,0,UART2_RX_BUFFER_LEN);
    return ret;

}