Hello,
I am doing a project using pic16f877 (battery powered). The system is currently switched on and off using a normal switch. I want to add a feature to the system that shuts off the power automatically if it was not used for a certain period of time (I get this information from a sensor).
I succeeded in getting the signal that indicates that the device is not being used from the pic. the problem is how can I use this signal to cut off the power ?
I am thinking of covering the on/off switch which is currently used to a push button, then using an OR gate with one input connected to the push button and the other input connected to the pin of the PIC that generates the signal. I am not sure if this is the best way to do it, so any suggestions are most welcome.
so, the first step is to build the circuit required for the push button. I have come across many circuits, and I am not sure which is the most appropriate circuit for a battery powered system.
1st circuit:
http://www.pcsilencioso.com/cpemma/flipflop.html
2nd circuit:
figure 1for denouncing and figure 2for latching
there are also those circuit which use the 555 timer.
Any suggestions on the best way to do this is much appreciated.
Thanks in advance
I am doing a project using pic16f877 (battery powered). The system is currently switched on and off using a normal switch. I want to add a feature to the system that shuts off the power automatically if it was not used for a certain period of time (I get this information from a sensor).
I succeeded in getting the signal that indicates that the device is not being used from the pic. the problem is how can I use this signal to cut off the power ?
I am thinking of covering the on/off switch which is currently used to a push button, then using an OR gate with one input connected to the push button and the other input connected to the pin of the PIC that generates the signal. I am not sure if this is the best way to do it, so any suggestions are most welcome.
so, the first step is to build the circuit required for the push button. I have come across many circuits, and I am not sure which is the most appropriate circuit for a battery powered system.
1st circuit:
http://www.pcsilencioso.com/cpemma/flipflop.html
2nd circuit:
figure 1for denouncing and figure 2for latching
there are also those circuit which use the 555 timer.
Any suggestions on the best way to do this is much appreciated.
Thanks in advance