[Discuss-gnuradio] PCI-DAS4020/12 problem roundup

[Ricky Hussmann]

Here's my update on the issues with 4020 board PC lockup.

Summary of the problem:

        I and apparently other users on the list are having trouble running any 
example program that uses the MC4020 multiple times. The first time running 
an example using the MC4020 after startup works flawlessly. However, after 
that example is closed and any other example run that uses the MC4020 the 
machine completely locks up.

Attempts at solutions:

First, I am working with the latest (0.7) driver for the mc4020.

I have applied Sergio's patch and tried recompiling GNU Radio. In his modified 
version of GrMC4020.h the line 

#include <mc4020.h>

is missing, so if you had problems compiling try inserting the above line and 
recompiling. After compiling his version of adc_fft.cc and testing it I WAS 
able to run the program multiple times. However, the graphs displayed a dead 
zero signal even though I was inputting a sine wave into the 4020. Also, 
Sergio simply uses a countdown from 1,000 to bypass exit from the loop and 
properly call the destructor for the GrSourceMC4020 class. This causes the 
program to terminate shortly after it started.

My thoughts:

        Just from the nature of the problem, I believe this is an issue with 
not 
correctly deallocating resources the device is using. I'm lead to believe 
this because:

1.) The machine locks up only after an example program has been run and closed 
and another has been executed.

2.) Sergio's call to the destructor allowed the program to be run multiple 
times, even though no data was displayed on the graphs in the adc3_fft 
program.

I haven't delved deeply into GNU Radio's core and I'm not sure I'd understand 
it if I did, but I'm willing to provide whatever assistance is necessary to 
solve this problem (it's really a pain when trying to work with the 4020 
board).

My hardware configuration:

        I'm using a Dell Dimension XPS T750r that appears to be using the Intel 
440 
BX/ZX/DX chipset. It is using the Intel PIIX4 Ultra 33 chipset for IDE 
control. It has a 750 MHz Intel P3 processor. I'm running Slackware 9.0 with 
the 2.4.20 series kernel stock from install.

Hope this can help,
Ricky Hussmann