当给GSM模块发送AT命令时，只能接收到如下数据啊？

goodgoodstudy

41 54 0D 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
41 54 0D 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
41 54 0D 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
41 54 0D 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
41 54 0D 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
41 54 0D 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
41 54 0D 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 
即：AT\r\n，什么原因啊？帮忙分析下，谢谢啦！（采用的是原子哥的串口发送和接收）
还有个问题是，GSM模块和STM32不共地也可以进行串口通信，我的明明没有进行共地，为什么还能正常工作呢？

goodgoodstudy

回复【7楼】正点原子:
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谢谢原子哥，现在可以了！

正点原子

慢慢调试,你这完全是没有回应.
先用串口助手调试下吧.

zhao305149619

有道理，要先在串口调试模块上调试好了，再上单片机

goodgoodstudy

回复【2楼】正点原子:
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串口当然已经调试好了啊。。然后上单片机就这样了、

goodgoodstudy

回复【3楼】zhao305149619:
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串口当然已经调试好了啊。。然后上单片机就这样了

goodgoodstudy

回复【2楼】正点原子:
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这个是GSM模块发送给单片机的数据，再回传给上位机的！

正点原子

回复【4楼】goodgoodstudy:
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说明你的单片机和GSM模块通信存在问题,检查代码,或者硬件连接.