Network Indicator Led; Adc And Pwm Pins - SimCom SIM900 User Manual

9. Network Indicator LED: Network Status Indicator LED.
State
Off
64ms On/ 800ms Off
64ms On/ 3000ms Off
64ms On/ 300ms Off
10. ADC and PWM Pins: ADC and PWM Pins of SIM900A.(Refer page 9,10 for ADC and PWM
commands)
11. Audio Interface: Audio Pins (Speaker and microphone pins) of SIM900/900A.
12. SIM Interface: SIM Card holder Interface.
13. Vout: Regulated 4.2V output voltage for external application circuit.
SIM900 function
SIM900 is not running
SIM900 does not find the network
SIM900 find the network
GPRS communication