[ell-i-developers] Re: Serial on stm32f334nucleo
- From: Ivan Raul <supra.material@xxxxxxxxx>
- To: "ell-i-developers@xxxxxxxxxxxxx" <ell-i-developers@xxxxxxxxxxxxx>
- Date: Thu, 18 Sep 2014 12:25:50 +0300
Hi,
The baudrate is set during the begin method:
https://github.com/Ell-i/Runtime/blob/master/stm32/cores/arduelli/Arduino_Serial.h#L64
So, in fact, we rewrite the register each time the serial is initialised.
(it would be possible to remove this baudrate setting from the
initialisation registers)
However, if the system clock was a constant, this calculation, and the
division involved,
would be done at compile time. But for safety reasons STM always make
runtime calculations.
as they consider the possibility of clocks failing to initialise.
With Warm Regards, Ivan Raul
On Thu, Sep 18, 2014 at 8:22 AM, Pekka Nikander <pekka.nikander@xxxxxx>
wrote:
> The code looks good to me, though I'm wondering where the correct baud
> rate comes from.
>
> Anyway, could someone please verify this independently? With a test
> report I'm willing to merge.
>
> --Pekka
>
>
> On 2014–09–17, at 22:31 , Ivan Raul <supra.material@xxxxxxxxx> wrote:
>
> > Hi to all,
> >
> > I was wondering if it is possible to receive serial communication
> through the stlink bridge of the nucleo. In fact, is possible, and I
> already provided a pull request for the change. I hope it helps a little
> for the testing of the new PoElli in the next weeks.
> >
> > Please, test accordingly :)
> >
> > mkdir temp
> > cd temp
> > git clone https://github.com/supramaterial/Runtime.git
> > cd Runtime/stm32/build/
> > make sketch.cpp
> >
> > #then, for testing, modify the sketch.cpp to something like this:
> > ##---------------------------
> >
> > #include <Arduino.h>
> >
> > void setup() {
> > Serial.begin(57600);
> > }
> >
> > void loop() {
> >
> > Serial.write('H');
> > Serial.write('e');
> > Serial.write('l');
> > Serial.write('l');
> > Serial.write('o');
> > Serial.write('\r');
> > Serial.write('\n');
> >
> > for (volatile int i = 0; i < 100000; i++)
> > ;
> >
> > }
> >
> > ##------------------------
> >
> > #then
> > make VARIANT=stm32f334nucleo
> >
> > #and flash
> > sudo st-flash write hardware/stm32f334nucleo/sketch.bin 0x8000000
> >
> > #the good part is that the stlink controller provides the USART2 through
> > #the usb, in linux it shows as /dev/ttyACM0
> >
> > #now, to test, use a serial console, minicom, for example
> >
> > #if minicom not installed
> > sudo apt-get install minicom
> > sudo minicom -s
> > #go to "serial port setup"
> > #configure in this way
> >
> > +------------------------------------------
> > | A - Serial Device : /dev/ttyACM0
> > | B - Lockfile Location : /var/lock
> > | C - Callin Program :
> > | D - Callout Program :
> > | E - Bps/Par/Bits : 57600 8N1
> > | F - Hardware Flow Control : No
> > | G - Software Flow Control : No
> > |
> > | Change which setting?
> > +------------------------------------------
> >
> > #then "save setup as dfl"
> >
> > #and run minicom
> > sudo minicom
> >
> > #it should show "hello" iteratively
> >
> > With Warm Regards, Ivan Raul
>
>
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