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Altera_Forum
Honored Contributor I
748 Views

Char Buffer UP IP

Hi  

 

I'm trying to realize a text terminal on VGA display using Char buffer and VGA control available in UP IP v9.0 

I've implemented the Nios on a DE1 board. 

 

 

I'm sure that the hardware works properly, since writing a value directly on the mem position, a char appear on the VGA monitor 

 

But I've some problem to write a suitable software. 

 

I tried with: 

 

 

int 

main() { 

 

int i; 

alt_up_char_buffer_dev * my_ch_buf; 

 

 

printf( "Nios II Alive!\n\n" ); 

 

 

my_ch_buf = alt_up_char_buffer_open_dev( "/dev/character_buffer_0_avalon_char_buffer_slave"); 

 

if ( my_ch_buf == NULL) 

alt_printf ("Error: could not open pixel buffer device \n"); 

else 

alt_printf ("Opened pixel buffer device \n"); 

 

i = alt_up_char_buffer_draw(my_ch_buf , 'A', 30,30); 

printf( "res=%d",i ); 

 

 

but the answer is :( "Error: could not open pixel buffer device": infact the function "alt_up_char_buffer_open_dev" does not open the device and so the subcessive function "alt_up_char_buffer_draw" is unable to write anything. 

 

Any suggestion? 

Is maybe available some C examples using this device ? 

 

Thank you in advance 

 

Stefano 

 

 

 

 

 

 

 

 

 

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1 Reply
Altera_Forum
Honored Contributor I
22 Views

OK, I solved the problem by myself: 

 

The correct neme of the device was: 

 

"/dev/character_buffer_0"; 

instead of 

"/dev/character_buffer_0_avalon_char_buffer_slave"; 

 

Whoever it is not clear for me where the "name" of the device is assigned 

i.e. where to find the correct name  

 

in the first release I used the name found in "system.h" which was of course wrong.
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