Max input frequency

Hello everyone, 

I have a micro2440 board, I want to read encoder pulse. Has anyone know the
    maximum frequency input?

Thanks very much and best regards!

Do you want to read the encoder from a GPIO port while running Linux?

Using userspace or kernel calls?

GPIO via userspace maybe 1000Hz
GPIO via kernel calls maybe 10 - ? kHz

No OS, maybe many MHz

Hi davef,

I'm using Wince 6.0, I want to measure the speed of conveyor (around 150
m/min). Is it possible to solve this problem?

Thanks very much!

Someone with Windows experience would need to answer.

How accurately do you want to measure the speed and maybe more importantly
how accurately do want to measure the rate of change in speed for control
purposes?

If you need the operating system for other reasons maybe you will need to
consider some RTOS extensions that work under Windows.

http://syncor.blogspot.ca/2011/07/signal-processing-on-windows-in-real.html
 

Good luck!

Hi,

I have an encoder with resolution 600 pulses per inch (maximum speed of
conveyor is 150 m per minute). My small project is calculate the speed of
the conveyor.

I've already programmed an application to read the pulse of the encoder via
GPIO, but it's too slow to read the pulses when i'm turning the encoder.
When a round is turned with slow speed, the application can read only ~500
(exact value is 5000).

Is there other way to read faster?

Best regards!

What I would take a serious look at this board plugged into your USB port.

http://adafruit.com/products/296

Then go here to get code to run on the board:

http://www.pjrc.com/teensy/

then this page to get a project similar to yours

http://www.pjrc.com/teensy/projects.html

I am sure there will be something that will do pulse counting up to
10-20MHz with the ATmega32U4.

This way you can run nice GUI programs on the mini2440 and have the serious
embedded requirements handled by a system that doesn't have an OS to "get
in the way".

http://msdn.microsoft.com/en-us/library/ms836797.aspx

Looks like getting sub 1ms is difficult.

http://www.atmel.com/Images/doc7766.pdf

See page 115 "input capture"