Why is my sim900 not connecting to the network?

Why is my sim900 not connecting to the network?

AT commands are working but no network, not connecting to the network (nw led blinking every 1s 7times and then 4-5s delay ) what could be the possible solution?

How to Turing a sim900 / sim800 module?

Turing the module ON : You need to provide the proper duration ON pulse on the PWRKEY pin of SIM900/SIM800 to turn it ON. Not too long and not too short. 1 second pulse is recommended. Also take care of the IO levels here also. In evaluation modules normally a switch is provided.

What should the IO voltage be on sim900?

IO voltage levels : The voltage levels acceptable on the SIM900/SIM800 UART pins is 2.8V- 3V . So its IO system works at 2.8V levels. If you are interfacing to a controller running at 5V or 3.3V then it might damage the IO driver circuit of the modules UART pins.

How to put sim900 / sim800 into sleep mode?

For power saving you need to use the command AT+CSCLK=2 to put SIM900/SIM800 into sleep mode 2 whenever it is IDLE.  It goes into sleep mode at 5 seconds of inactivity on UART or network and wakes up whenever a event like a Call/SMS occurs.

What does it mean when your sim800 is not working?

If you are getting basic AT commands to work but other AT commands for HTTP, FTP, DTMF, EMAIL are not working then it means that you need a firmware update. Watch this video for more details, 

Why is my sim900 not outputting URC?

Normally when it doesnt get enough power or current, it outputs a URC string like NORMAL_POWER_DOWN or UNDER_VOLTAGE_POWERDOWN, only if it is already ON. If it is starting up and there is not enough power for it to consume then it will keep switching On and off and it will not output any URC making it hard to debug.

What should the voltage be on sim900 UART pins?

Use thicker tracks and multiple vias for making better connections. if power source is too far then use a 1000uF capacitor very close to the VBAT pins. IO voltage levels : The voltage levels acceptable on the SIM900/SIM800 UART pins is 2.8V- 3V . So its IO system works at 2.8V levels.