How use serial::attach(&callback) in mbedOS

Mbed OS
1

when I use like follow code ，it can’t operate correct. thank you!

#include “mbed-drivers/mbed.h”
#include “minar/minar.h”
#include “core-util/FunctionPointer.h”

using namespace mbed::util;

static DigitalOut led(LED1);

static void led_toggle_user(void) {
led = !led;
// printf(“LED = %d \r\n”, led.read());
}

static void led_toggle_irq(void) {
minar::Scheduler::postCallback(FunctionPointer0(&led_toggle_user).bind());
}

void app_start(int, char**) {

static Serial pc(USBTX, USBRX);
pc.attach(&led_toggle_irq);
led = 1;
while(true)
{
wait(5);
led = !led;

}

}

2

Hi,
app_start in mbed is a minar event only, not like a main application. As the minar is a preemptive scheduler, we have to terminate an event to process another. so we should not use an infinte loop in app_start or any event. I hope that is the issue in your code.

refer the following link : GitHub - ARMmbed/minar: mbed OS scheduler

Thanks

3

when i remove the infinte loop the problem still exists. My purpose is receive uart message in mbedos ,what should i do ? thank you !!!

4

Hello,

there are not sufficient information provided.

what target are you using? yotta list - share the output, are all modules up to date?

You should not use static Serial pc(USBTX, USBRX);. If you want to use stdio Serial object, use :

/** Get the stdio Serial object, which is lazy instantiated.
 *
 *  @returns stdio object 
 */
Serial& get_stdio_serial();

in the app:

Serial& pc = get_stdio_serial();
5

the follow code can run correct on frdm-k64f-gcc 2.0.0 ,but got frozen on st-nucleo-f401re-gcc 0.2.4 board ,if I want make 401 can also run the code which source should modified ? thanks !!!

#include "mbed-drivers/mbed.h"
#include "minar/minar.h"
#include "core-util/FunctionPointer.h"
using namespace mbed::util;
static char buf [10];
static DigitalOut led(LED1);
//static DigitalOut led(YOTTA_CFG_HARDWARE_PINS_D4);
static Serial pc(USBTX, USBRX);

static void led_toggle_user(void) {
led =!led;
//pc.printf("receive");
buf[0]=pc.getc();
}
static void test(){

pc.printf(buf);
}


void app_start(int, char**) {

pc.attach(&led_toggle_user);


buf[0]='*';
buf[1]='\0';

led=1;
minar::Scheduler::postCallback(test).period(minar::milliseconds(500));
}
6

when I use target st-nucleo-f401re-gcc 0.2.4 board the code got frozen, but frdm-k64f-gcc 2.0.0 works well,my purpose is make 401 can run the code correct ,can you give me some hints please? thank you !!! (the code gives in above)

7

Please don’t use static Serial pc(USBTX, USBRX) with mbed-drivers >= 0.12.x .Use the API shared above.

cc @bcostm

8

I want use serial communicate with other device ,not just USBTX/RX ,the API you shared above is just about USBTX,UBSRX pins ,right? -_-

9

I want use serial communicate with other device ,not just USBTX/RX ,the API you shared above is just about USBTX,UBSRX pins ,right? --@Kojto
yotta list output
_ mbed-drivers 0.12.1
| mbed-hal 1.2.2 yotta_modules\mbed-hal
| _ mbed-hal-st 1.0.0 yotta_modules\mbed-hal-st
| _ mbed-hal-st-stm32f4 1.1.2 yotta_modules\mbed-hal-st-stm32f4
| |_ uvisor-lib 1.0.12 yotta_modules\uvisor-lib
| |_ mbed-hal-st-stm32cubef4 1.0.2 yotta_modules\mbed-hal-st-stm32cubef4
| _ mbed-hal-st-stm32f401re 0.1.2 yotta_modules\mbed-hal-st-stm32f401re
|_ cmsis-core 1.1.2 yotta_modules\cmsis-core
| _ cmsis-core-st 1.0.0 yotta_modules\cmsis-core-st
| _ cmsis-core-stm32f4 1.0.5 yotta_modules\cmsis-core-stm32f4
| _ cmsis-core-stm32f401xe 0.1.0 yotta_modules\cmsis-core-stm32f401xe
|_ ualloc 1.0.3 yotta_modules\ualloc
| _ dlmalloc 1.0.0 yotta_modules\dlmalloc
|_ minar 1.0.4 yotta_modules\minar
| _ minar-platform 1.0.0 yotta_modules\minar-platform
| _ minar-platform-mbed 1.1.0 yotta_modules\minar-platform-mbed
|_ core-util 1.2.0 yotta_modules\core-util
_ compiler-polyfill 1.2.1 yotta_modules\compiler-polyfill

10

I want use serial communicate with other device ,not just USBTX/RX ,the API you shared above is just about USBTX,UBSRX pins ,right? -_-

Yes only for stdio. The above example defines Serial object for USBTX, RX

11

the mbed classic sdk can not run in mbed os 3.0? I just want migrate my project from mbed sdk to mbed os …

in my project just need serial ,can I remove minar module and just use main fun()? because the mbedos new feature for my project is not used.