I'm using a SIM800C module, and usually it works fine, but lately it has started giving the error "+CPIN: NOT READY" with ERROR CODE : +CME ERROR: 10(SIM NOT INSERTED). As soon as I get this message, the voltage on SIM_VDD drops to 0V. The problem is intermittent (i.e. it happens only sometimes).
I have read all related posts on here. Here is some info on my setup: -Schematics is designed according to SIM800C documentation. -I use 6-pin SIM connector. -Adding decoupling caps on SIM_VDD, on input power, and on VBAT (for SIM900) does not help. -Signal strength is fine (about CSQ=20). -I tried reinserting different SIM cards, nothing helped
The "+CPIN: NOT READY" is sent at different times, however, often quite soon after power on.After removing battery & attaching it again, starts working again. why this issue is occuring..?