How can I automatically turn on at power-up of the GM862-GSM/GPRS?
The GM862-GPRS GM862-GSM needs a negative pulse of at least 1s on the ON* pin of its connector to turn-on.
This is obtained with an open collector transistor.
For the control of the real turn-on of the module or to control possible shutdown due to power drops during the functioning of the module, you can check the PWRCTL (also named START) line. The PWRCTL line remains high (2.7V for GM862-GPRS and GM862-GSM) for all the time the module is ON.
It is therefore possible to design a small circuitry to turn-on the module automatically when it`s powered, it is even possible to add some circuitry in order to turn on again the module if it has been shutdown (for example by an external RESET) without the need for resetting the power supply.
If you want the module just to turn-on when powered (but turn-off if AT#shdn command issued) please ask Round Solutions.
Some adjustments may be needed in the values of: R2, C3 and R3,R4,C2 depending from the VBATT to adjust pulse timings.
Examples of circuits may be obtained by Round Solutions.
Please e-mail Round Solutions and ask for the "Power-Up-Circuit".