gprs模块使用定时器中断进行tcp通信定时发送信息但网络调试助手没有接受到信息

我在一个函数中使能定时器3 同时在定时器3的中断服务函数中加入如下代码
        u16 adcx;float temp; float temperate;  u8 *p1;        u8 *p;        p=mymalloc(SRAMIN,100);//申请100字节内存p1=mymalloc(SRAMIN,100); sim900a_send_cmd("AT+CIPCLOSE=1","CLOSE OK",100);//关闭连接sim900a_send_cmd("AT+CIPSHUT","SHUT OK",100);//关闭移动场景 if(sim900a_send_cmd("AT+CGCLASS="B"","OK",1000)==0)printf("AT+CGCLASSn");//设置GPRS移动台类别为B,支持包交换和数据交换 if(sim900a_send_cmd("AT+CGDCONT=1,"IP","CMNET"","OK",1000)==0)printf("AT+CGDCONTn");//设置PDP上下文,互联网接协议,接入点等信息if(sim900a_send_cmd("AT+CGATT=1","OK",500)==0)printf("AT+CGATTn");//附着GPRS业务if(sim900a_send_cmd("AT+CIPCSGP=1,"CMNET"","OK",500)==0)printf("AT+CIPCSGPn"); //设置为GPRS连接模式if(sim900a_send_cmd("AT+CIPHEAD=1","OK",500)==0)printf("AT+CIPHEADn"); //设置接收数据显示IP头(方便判断数据来源)sprintf((char*)p,"AT+CIPSTART="%s","%s","%s"","TCP","125.217.248.45","8086");if(sim900a_send_cmd(p,"OK",500)==0)printf("OK");adcx=Get_Adc_Average(ADC_CH_TEMP,10);temp=(float)adcx*(3.3/4096);temperate=temp;//保存温度传感器的电压值 temperate=(1.43-temperate)/0.0043+25;allterm=temperate;sprintf((char*)p1," %f ",temperate);if(sim900a_send_cmd("AT+CIPSEND",">",500)==0)//发送数据{ u2_printf("%srn",p1);delay_ms(10);if(sim900a_send_cmd((u8*)0X1A,"SEND OK",1000)) return ;}
希望能实现STM32内部温度传感器值的定时发送，但是很奇怪网络调试助手没有接受到信息，
同时用串口调试助手调试发现也没有收到信息，但是如果把这几行代码放在while循环里面就没有问题，求解决。。。。