fritz-net
Newbie level 2
Hello, I have designed a PCB with a sim900 but no matter what I do it is not recognising my sim card. When it boots it says: "+CPIN: NOT INSERTED"
I attached a picture of the schematic, a scope where blue is the status LED and pink the simVDD and a picture of the solderd sim socket because I'm not sure if my pinout is right.
Here is the serial log:
I checked the pinout several times cause I often read that this could be the problem and I removed the ESD protection after that I got proper voltage on VDD before there was only short a low level voltage. I also removed the presence 10k pullup and let the pin float.
I hope someone can help and thx for reading
I attached a picture of the schematic, a scope where blue is the status LED and pink the simVDD and a picture of the solderd sim socket because I'm not sure if my pinout is right.
Here is the serial log:
Code:
�����
RDY
+CPIN: NOT INSERTED
+CFUN: 1
AAAT
OK
AT+ATE0
ERROR
AT+CPIN?
+CME ERROR: SIM not inserted
I checked the pinout several times cause I often read that this could be the problem and I removed the ESD protection after that I got proper voltage on VDD before there was only short a low level voltage. I also removed the presence 10k pullup and let the pin float.
I hope someone can help and thx for reading
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