What are the things to be considered when connecting 3-4 different modules to raspberry pi3?
Ex: i am using 4 modules namely RFID reader, hall effect sensor, gps and some push buttons. Need to connect all at once. But some of the gpio pins are same for different modules(if i am using pin number 24 for rfid, the same 24th is required by hall effect sensor). So i searched in google and found gpio expander.
If i use gpio expander can i be able to use a pin multiple times? RFID need 3.3v, hall effect sensor and gps need 5v.
Can i connect it to respective voltages ? Does raspberry pi supplies the need of all modules at a time?
Since i am developing a portable project i have to use a battery as power supply instead of usb adapter for raspberry pi.
Which battery is suitable? 5v or 9v?
Are any other solutions there instead of battery and usb?
This is all the doubts i had and couldn't find answers anywhere. These questions might look silly 😬. Thank you for your time.