interrupt driven usart2 reception not working

[kiran2]

Posted on February 16, 2015 at 03:11

Hi,This is kiran kadam.currently i am working on gsm based project.tools i am using for development are stm32f429 disco board,sim900 module,level converter and ewarm7.3

i am stuck at interrupt driven uart.i have written code for usart but code does not work properly.i know i am missing something but could not trace out.even i tried example code from st dedicated for this board that too didnt worked out.pls help me out as soon as possible as it is urgent for me.i can see TXE ,TC flag are set but receiving giving me trouble.for instance i have shorted TX,RX to echo back whatever i am sending. pls help your help will be appreciated.

 

Regards,

Kiran Kadam

[Tesla DeLorean]

Posted on February 16, 2015 at 04:36

So should we guess how you're wired this up, and how you have the software configuring things now?

[kiran2]

Posted on February 16, 2015 at 05:04

Hi,as  i told earlier for time being i have just shorted tx(PA2) and rx(PA3) on discovery board.i am trying to work out usart first .from st example project port pins PA9 & PA10 have been used.

[kiran2]

Posted on February 16, 2015 at 07:23

hi clive1,pls help me out asap as it is urgent,

Thanks in adv.

[Tesla DeLorean]

Posted on February 16, 2015 at 16:42

Wouldn't PA3 clash with one of the LCD pins?

As I recall I've posted several F4 USART IRQ examples to the forum.

[kiran2]

Posted on February 17, 2015 at 07:06

hi clive1,i have only usart activated in my project.i am not using any other peripherals for time being...can you tell me is there difference in peripheral address remapping in stm32f407 & stm32f429?? 

[kiran2]

Posted on February 18, 2015 at 06:08

Hi clive1, code works fine now as i have switched to usart1.i dont understand why i cannot use usart2??on discovery board usart2 function is unavailable??how many usart i can use on disco board?

Pls reply as soon as possible.i need atleast 3 uart

Thanking you.

Regards,

Kiran Kadam

[Tesla DeLorean]

Posted on February 18, 2015 at 13:52

You know you can download and review the documentation for these parts/boards yourself?

The

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/user_manual/DM00093903.pdf

does enumerated the available pin resources for the board. The pins are highly contended with the LCD and SDRAM features of the board. You'd correlate these with the pin data in the

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00071990.pdf

. This is no doubt a time consuming process, time I can't offer you.

[kiran2]

Posted on February 19, 2015 at 05:05

Thanks for help.i wanted know how can i interface 16x2 lcd to this board....since lcd operates at 5v and board at 3.3....how do i connect it?

[kiran2]

Posted on February 19, 2015 at 05:18

Thanks for help.i wanted know how can i interface 16x2 lcd to this board....since lcd operates at 5v and board at 3.3....how do i connect it?

[Tesla DeLorean]

Posted on February 19, 2015 at 12:31

Actually I think you'll find the main portion of the board is 3V, but there is a 5V supply which would likely suffice for the LCD. Or you could pick a more suitable LCD.

Olimex has many designed using typical 16x2 displays, you could review those designs. Beyond the supply/backlight/contrast, you'd need 4 data bits, and a couple of control signals for a minimal interface.