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Honored Contributor I

Need help in UART!

Hi everyone! 


I'm currently trying to use Serial port of DE1 cyclone 2education kit. With the nios system i generated i succesfully send and recieve data from my pc's usb port(i used usb to serial converter to connect rs232 socket something like this :) ). Anyway i send and recieved data from the usb port(i wrote a veery easy and basic serial port code in c# thanks to my friend ozan :) ) Now i try to use a bluetooth module which is using uart to communicate. This bluetooth module is a little problematic. It requires "max"3.3 or 3.6 V inputs for each its inputs-expect gnd.( rx,tx,vcc, etc(total 6 inputs) ). As i know Max232's outputs are aproximately 12-15v(i hope i'm not wrong ;) ) 

Thus i can't use the rs232 connector. My problem starts here. 

I think i should use the GPIO pins. I tried them too. I assinged some of GPIO pins to UART tx and rx. When i program my board, the TX and RX leds(between rs232 and vga connectors)are constatnly on. I open nios and build a project which sends some data from TX pin i assigned. When i tried to run it on my board it gives; 

Downloading xxx ( 0%) 

Downloading xxx (xx%) 

Downloaded xxKB in xxs 


Verifying xx ( 0%) 

Verify failed between address 0x0000 and 0xE8xx (i can't remember xs. They usually change every time i try another nios project with same system ) 

Leaving target processor paused 


Then i thought that this error occured because i tried to use wrong pins. I regenerate my system with 2 uart components. One assigned to sefault UART pins the others assinged to my GPIO pins. Then i had the same error. At the end i tried a very simple hello world sample. And same error again.  


I don't understand the cause. As you can understand my -even longer- story, i did some reverse-engineering :p . I can't succeed though. I think my problem occures because some memory problem. I use SRAM controller(which cames with university ip core libraries). 


I have to control a device via bluetooth modules remotely. And i only have these modules i explained above. Thus, i need help  


*extra question: I should have asked this early in the text but can i assing any pins to any module ? Like this problem, can i assign different pins to uart module? Thank you for your answer. 


Thanks for your help at this very moment. Again any help would be great. 




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3 Replies
Honored Contributor I

I think I posted this thread to wrong place. I apologize for my mistake. (Butmy question contains these topics: Quartus system generation and assignments, Nios uart codes, University program IP core components(such as SRAM). I'm a little confused so again i'm sory). I'm waiting for your answer

Honored Contributor I

It seems i found a solution. Actually this problem is caused by my carelessness. Luckily ,I solved it and i can use every gpio pins as tx or rx. Now my problem is how to use that blue tooth module :D . Nobody answered, but thank you anyway

Honored Contributor I

Glad you got your problem sorted! 


Often the (sometimes painful) process of self-discovering a solution is the key to developing experience - have been there and done that more than a few times. :) Gives you a good feeling when you know you sorted it yourself too!