Once a new module has been written, or if something new should be tried, a new testing-module should be written. A testing-module usually consists of a simple chain with some output that tells the user whether the test has succeeded or not. It is the first step towards writing a Radio and using a new or modified module in real-time.


If you want to start a new test, create a new directory under Test/ and add the name to the line

DIRS = FirstChain Memory ... 
of the file Test/Makefile. Like this your test will be automatically built when using make whole. Next cd in your new directory and copy some files:

cp ../../Conventions/test_template.c \

   ../../Conventions/Makefile.module . 

The test_template.c should be renamed to something fitting the pattern test_*.c, and this name should be appended to the line

of the Makefile (which has been renamed from Makefile.module). Now you are ready to modify your test_*.c file and test it out, using


make user 

You can also have a look into different files that you find in the directory Testing/* to see different techniques on how to do strange things.


The main-part of the module is in the function start_it. It is called once when the module is loaded. For a small testing-module you want to make perhaps only a small chain, something like

swr_chain_create( NEW_SPC_VAR( ''random'', rnd ),

                  NEW_SPC( ''modulator'' ),

                  NEW_SPC( ''demodulator'' ),

                  NEW_SPC_VAR( ''sink'', sink ),

                  CHAIN_END ); 

This leads to an empty chain, because all modules (with the exception of the STFA and the block module) have an input- and output-size of 0. So we need to set one module to a given size:

swr_sdb_set_config_int( sink, ''size'', 128 ); 
And while we're at it, we can tell the sink module, that it should count the occurences of the different values:

swr_sdb_set_config_int( sink, ''flag'', 2 ); 
For further explanation, you can turn to the explanation of the sink module.

Now that the chain has been created and configured, it still needs to be activated at least once, so that something happens:

swr_sdb_seng_msg( rnd, SUBS_MSG_USER, NULL, -1 ); 
Which sends a user-defined message to the random module. It will now traverse the whole chain and the sink module will output the occurances of the different values. To compile and start it, type the following commands:


make user 

As the size of the sink-input is only 128, this will not be very representativ for the random-number generator. You may increase the size of the sink-input to something like 65536 or even more, to see how the random-number generator works.

Linus Gasser 2004-04-14