astolia 写了: ↑2019-11-27 12:18
你试过其他的SIM卡查询命令没有?如果其他的也是这种错误,那用ATI命令确认一下ttyusb3确实是你的ec20模块吗?还有如果模块有探测sim卡是否存在或者进行初始化的命令,也用一下试试
谢谢大佬,我终于读出来了,但是是很莫名其妙的就成功了,我先使用AT+QPOWD
It is recommended to execute AT+QPOWD command to turn off the module, as it is the safest and best
way. This procedure is realized by letting the module log off from the network and allowing the software to
enter into a secure and safe data state before disconnecting the power supply.
After sending AT+QPOWD, do not enter any other AT commands. The module outputs message
POWERED DOWN and sets the STATUS pin as low to enter into the shutdown state. In order to avoid
data loss, it is suggested to wait for 1s to switch off the VBAT after the STATUS pin is set as low and the
URC POWERED DOWN is outputted. If POWERED DOWN has not been received within 65s, the VBAT
shall be switched off compulsorily.
然后在打AT+QCCID就显示成功了,然后我又直接重启整个板子,SIM卡并没有拔,然后直接打AT+QCCID后结果仍然返回了。然后我把sim卡给拔了,在插上再次使用AT+QCCID 然后就显示+cem error:13的错误。然后我用AT+QSIMSTAT? 查看sim卡的插入状态发现,并没有插上。我在使用AT+QPOWD之后,再使用AT+QCCID指令,结果就正确返回了,这是不是跟sim卡的热插拔有关啊?
我还有最后一个疑问,具体情况如下:
root@firefly:/home/firefly# socat - /dev/ttyUSB3
AT+QCCID(这是我自己输入的)
AT+QCCID(命令显示的)
+QCCID:929293939494929
OK
(这往上都可以理解为该指令返回的)
AT+Q
ERROR
AT+Q
ERROR
(就是这最下面的四行,除了那个AT+QPOWD外,其他的指令都会多上这四行,不知道是什么情况)
谢谢大佬了!!