Can anyone please confirm to me how many I/O is available to the user on the GPIO port? Are all of the I/O available for use or are some reserved for internal functions? I need 10 inputs and a minimum of 4 outputs. Is this acheivable? Thanks in anticipation.
You probably need to tell us which board you want to use? 14 gpio pins sounds achievable though :D
Hi Reggie, regarding the GPIO's i found following on Geetech: "Notes: the camera interface is a multiplexed port. It can be used as GPIO by setting corresponding registers" Maybe i need for later projects more GPIO than accessible on CON6 of Micro2440. How can i do this respectively which registers i have to change to what? Thanks in advance!
Now that we have the board model, I can tell you I don't own one, hopefully someone who does might be able to answer these questions for you.
None of my devices or their schematics show a CON6 so I'm nont sure which board you are referring to but I don't think it is a Micro2440. If it is the Mini2440 then the "GPIO" connector is the one you want to use. By default it is configured as: 10 inputs (All selectable as external interrupts) 4 analog inputs (0 - 3.3V) 4 outputs that are connected to the onboard LEDs 2 I/O (GPG13,14) which must be configured as inputs in NAND boot mode 2 I/O (GPB0, 1) which are configured as TOUT0, 1 (one for the buzzer) SPI interface IIC interface 3.3V 5V If you are not using SPI then those 4 pins can be configured as inputs or outputs, any of the 10 inputs can also be configured as outputs, the timer outputs (TOUT0, 1) can also be confgured as inputs or outputs. Regards, Rob Of course if you are not using the Mini2440 then you would probably want to ignore this.
Hi Rob, From your above description, is that all GPIO 34 lines are free to configure on mini2440? If ie. so can u please give me an info/link how to configure a gpio for 4x4 keypad? Thanks, ./J
I used GPJ (camera) as GPIO to my project. Works fine.