Hi, Is it possible to use LCD connector as GPIO, If yes, is there any drawback of using LCD interface as GPIO? because I found GPC and GPD on same interface. @davef, could you please guide me on this...? Look forward to hear from you soon.
From someone who has just got GPIO, ADC and SPI working on a ATmega32U4 board that I plug into the mini2440 USB port :) From my limited understanding it appears you can use those ports for GPIO. They appear to have the same functionality as other GPIO ports. A rough count gives about 20 GPIO available on the GPIO connector. Do you need more than that?
@davef, yes I am driving one card that is having 38 gpio, so I will need more than 20 GPIO and I want it on same Bank. I found GPD is on the same bank and I can operate 16 IO at once. Could you please tell me timer resolution for the GPIO? i.e. what time it require to operate 16 GPIO at once...? -- tinyarm
Could you please tell me timer resolution for the GPIO? i.e. what time it require to operate 16 GPIO at once...? User space GPIO access I believe is limited by the system timer. Think that can be reduced to something like 1ms. 16 GPIO, I'd guess up to 50ms. If you write a kernel driver I believe you can make things happen a lot faster. Haven't tried myself. I have only used GPIO from user space (sysfs) and was seeing delays of several ms. I did some research on trying to make a 5-10MHz DSO on this platform and gave up. Have you looked at SDIO (on the mini2440) and what it might offer?
On 2nd thought SDIO is probably not very useful. What about an I2C port expander?