On Fri, Dec 12, 2008 at 3:58 AM, James Drummond
<biometalhelix@xxxxxxxxx> wrote:
I graduated college about 3 years ago as a computer engineer. I have not worked on fpga board since then where I used a Sparten 3 board. I just order a Nexys-2 (Spartan 3e) to do some home projects. I am new to ucLinux but use linux. I think I will be able to setup the board following the instructions from petalinux.
Does the Nexsys have enough external RAM for Linux? You want at least 4Mbyte as a minimum.
However, I am unable to find how to send PWM signals out. The PWM signal will go through a NPN transitor and then drive a piece of biometal helix.
You need a PWM controller IP core. You can either use the xps_timer in PWM mode, or create your own. However, there is no Linux driver for the xps_timer in PWM mode, you iwll need to write it yourself. You could use the gpio driver as a starting point.
If you write your own PWM controller, then against you'll need a driver.
How would I measure the resistance of the biometal wire that is changing. Is there some kind of external device that I need to output a signal back to the fpga board or can the fpga handle this directly. How/which device in the /dev folder would I access the input.
You'll probably need to measure the voltage across the wire and the current through it, and do the arithmetic! For this you'll need some simple ADC, some interfacing hardware, and again a device driver. There is no existing driver in the PetaLinux tree that will do this for you, however there are many examples you can copy and modify for your needs.
Also there are some nice example programs in the petalinux distribution like gpio_test.c but I was wondering if there are some more simple examples like the ones from petalinux out there.
Not sure what you mean here?
What is the best way to figure out what each device can do in the /dev folder and how to use them?
google on the device name maybe? If you have a specific question then fire away, otherwise it's a bit broad for a general answer.
Regards,
John