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专家
2015-11-04 15:42:42     打赏
11楼

mbed还没康复

莫非和google一样悲催啦




专家
2015-11-04 15:49:13     打赏
12楼

我冤枉伟大的D和ZF了。

原本以为是因为G-F-W的问题打不开

结果用工具测试了一下,从国外也打不开

话说已经5-6个小时啦。

所以基于web的IDE啥的还是不靠谱呀



专家
2015-11-04 15:54:11     打赏
13楼

回头和大神学用keil玩吧

话说十五六年没用keil了,忘干净鸟,即使没忘干净,现在的变化也应该老大了吧



专家
2015-11-05 16:59:25     打赏
14楼

nucleo的RTC


昨天先是mbed站点坏掉

然后等了好几个小时,mbed终于康复了

然后EEPW服务器的网线又被老鼠咬断了


说一下nucleo的RTC吧

话说这个stm32L053R8处理器是带RTC的

(这里写着呢,https://developer.mbed.org/platforms/ST-Nucleo-L053R8/)


mbed也提供了一个显示时间的例子(尽管有点简陋):


#include "mbed.h"
 
DigitalOut myled(LED1);
 
int main() {
    
    printf("RTC example\n"); 
    set_time(1387188323); // Set RTC time to 16 December 2013 10:05:23 UTC
    printf("Date and time are set.\n");
 
    while(1) {
 
        time_t seconds = time(NULL);
 
        //printf("Time as seconds since January 1, 1970 = %d\n", seconds);
        
        printf("Time as a basic string = %s", ctime(&seconds));
 
        //char buffer[32];
        //strftime(buffer, 32, "%I:%M:%S %p\n", localtime(&seconds));
        //printf("Time as a custom formatted string = %s", buffer);
 
        myled = !myled;      
        wait(1);
    }
}


其实核心就是这个set_time()


/** Set the current time
 *
 * Initialises and sets the time of the microcontroller Real-Time Clock (RTC)
 * to the time represented by the number of seconds since January 1, 1970
 * (the UNIX timestamp).
 *
 * @param t Number of seconds since January 1, 1970 (the UNIX timestamp)
 *
 * Example:
 * @code
 * #include "mbed.h"
 *
 * int main() {
 *     set_time(1256729737); // Set time to Wed, 28 Oct 2009 11:35:37
 * }
 * @endcode
 */
void set_time(time_t t);


不过这个其实很不方便,鬼知道1256729737咋查出来了


不过还好我们有

struct tm {
    int tm_sec;   /* seconds after the minute, 0 to 60
                     (0 - 60 allows for the occasional leap second) */
    int tm_min;   /* minutes after the hour, 0 to 59 */
    int tm_hour;  /* hours since midnight, 0 to 23 */
    int tm_mday;  /* day of the month, 1 to 31 */
    int tm_mon;   /* months since January, 0 to 11 */
    int tm_year;  /* years since 1900 */
    int tm_wday;  /* days since Sunday, 0 to 6 */
    int tm_yday;  /* days since January 1, 0 to 365 */
    int tm_isdst; /* Daylight Savings Time flag */
    union {       /* ABI-required extra fields, in a variety of types */
        struct {
            int __extra_1, __extra_2;
        };
        struct {
            long __extra_1_long, __extra_2_long;
        };
        struct {
            char *__extra_1_cptr, *__extra_2_cptr;
        };
        struct {
            void *__extra_1_vptr, *__extra_2_vptr;
        };
    };
};


我们还有:
extern _ARMABI time_t mktime(struct tm * /*timeptr*/) __attribute__((__nonnull__(1)));
/*
* converts the broken-down time, expressed as local time, in the structure
* pointed to by timeptr into a calendar time value with the same encoding
* as that of the values returned by the time function. The original values
* of the tm_wday and tm_yday components of the structure are ignored, and
* the original values of the other components are not restricted to the
* ranges indicated above. On successful completion, the values of the
* tm_wday and tm_yday structure components are set appropriately, and the
* other components are set to represent the specified calendar time, but
* with their values forced to the ranges indicated above; the final value
* of tm_mday is not set until tm_mon and tm_year are determined.
* Returns: the specified calendar time encoded as a value of type time_t.
*          If the calendar time cannot be represented, the function returns
*          the value (time_t)-1.
*/

 




所以我们可以这样:

	 struct tm mytime;
	 time_t seconds;
	

	 mytime.tm_year = xxx;
         mytime.tm_mon = xxx;	 
	 ....

然后:
         seconds = mktime(&mytime);
	 set_time(seconds);



记得年是从1900年开始的,所以如果你需要存2015,那么赋值应该写成:
mytime.tm_year = 2015 - 1900;


同理月是从0开始的,所以,如果你想保存11月,那么赋值部分应该写:
mytime.tm_mon = 11-1;


这样是不是优雅多了?


专家
2015-11-05 17:25:29     打赏
15楼

nucleo的RTC续(一)


好吧,程序挺优雅的,自己先吐,免得被你们吐。

STM32L053R8带个RTC也挺优雅

mbed提供了rtc的读写也挺优雅

都优雅,那么貌似不用写什么续集了,骗字数也不能这样不厚道吧?


其实不然,别看楼主平时做事低调,但是做人是相当厚道的。

废话少说(其实是说了很多废话说不动了):

举个栗子,你买个手机,设置好时间后,关机再开机,时间又变成1900年1月1日,你啥心情

这个nucleo就系这样,新都睡了

设置完时间,不断电,按reset,时间就木有啦。


大神的改造,话说我完全看不懂他做的啥,画的啥。感兴趣的去看看

https://developer.mbed.org/users/kenjiArai/notebook/nucleo-series-rtc-control-under-power-onoff-and-re/


专家
2015-11-05 20:43:59     打赏
16楼

nucleo的RTC续(二)


如前所述,对于我等菜鸟,STM32L053R8的RTC想用起来是有极大的障碍啦。除非不断电也不重启。

还好,我手头有一个用于Arduino的ds3231模块,在Arduino上用着挺好的,就想想能不能用于这个上呢。


说做就做,先连上再说

5V, GND, SDA, SCL貌似这几根线需要连

按Arduino的连法(A4 SDA, A5 SCL)

I2C i2c(A4, A5); 


然后上电RESET后给出提示:
(pinmap not found for peripheral)

研究半天,大概就是A4, A5没I2C功能 ,说好的兼容Arduino UNO R3呢, 做人咋不信守承诺呢?


好吧,找一下针脚图

SDA, SCL对应的是D14, D15, 可以在程序中直接用:I2C_SDA, I2C_SCL代替


I2C i2c(I2C_SDA, I2C_SCL); 

貌似不出错了

然后呢,试验一下能不能用吧

合计按Arduino的库改写一下,应该没啥难度吧


比如这个:


byte DS3231::getDate() {
	Wire.beginTransmission(CLOCK_ADDRESS);
	Wire.write(uint8_t(0x04));
	Wire.endTransmission();

	Wire.requestFrom(CLOCK_ADDRESS, 1);
	return bcdToDec(Wire.read());
}

看起来So Easy嘛


然后,仿照mbed I2C的例子改造一下

#include "mbed.h"
 
// Read temperature from LM75BD
 
I2C i2c(p28, p27);
 
const int addr = 0x90;
 
int main() {
    char cmd[2];
    while (1) {
        cmd[0] = 0x01;
        cmd[1] = 0x00;
        i2c.write(addr, cmd, 2);
 
        wait(0.5);
 
        cmd[0] = 0x00;
        i2c.write(addr, cmd, 1);
        i2c.read(addr, cmd, 2);
 
        float tmp = (float((cmd[0]<<8)|cmd[1]) / 256.0); printf("Temp = %.2f\n", tmp); } }
#include "mbed.h"

#define DS3231_ADDR   (0x68)

Serial pc(USBTX,USBRX);
I2C i2c(I2C_SDA, I2C_SCL); 
DigitalOut myled(LED1);

int main()

{
	  char data_write[10];
    char data_read[10];
	
	  data_write[0] = 0x00;
    //data_write[1] = 0x02;
	
		int status ;

		status = i2c.write(DS3231_ADDR, data_write, 1, 0);
		pc.printf("Return Value:%d\r\n", status);
    if (status != 0) { //NO ACK
				pc.printf("I2C Write status Error\r\n");
    }	 

		
	 status = i2c.read(DS3231_ADDR, data_read, 7);
	 pc.printf("\r\nReturn Value:%d\r\n", status);
	 if (status != 0) { //NO ACK
				pc.printf("I2C Read status Error\r\n");
    }	 
			 
	 for(int i=0; i<7; i++) pc.printf("%x\t", data_read[i]); pc.printf("\r\nI2C Test End!\r\n"); }

然后呢,貌似根本不工作

Return Value:1
I2C Read status Error
ff	ff	ff	ff	ff	ff	ff	
I2C Test End!
Return Value:1
I2C Write status Error


差哪里呢?

且看下文分解


专家
2015-11-05 20:50:06     打赏
17楼

EEPW的论坛编辑器插入代码部分靠色

对我这种色弱的人来讲,简直是灾难啊

所以如果插乱,别奇怪


专家
2015-11-05 20:53:26     打赏
18楼

话说,贴的Arduino部分和改的部分不一样

贴的Arduino部分是里边获取日期的部分


改写的部分是获取年月日时分秒等数据的。

仅供参考,勿怪。



专家
2015-11-05 21:04:35     打赏
19楼

nucleo的RTC续(三)


为啥例子里读那个LM75BD就会返回正确数据,而我这个就不能呢?


然后追踪了一下Arduino的代码。


在:

uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length, uint8_t sendStop)中

  // build sla+w, slave device address + w bit
  twi_slarw = TW_READ;
  twi_slarw |= address << 1;

 在:

uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait, uint8_t sendStop)

  // build sla+w, slave device address + w bit
  twi_slarw = TW_WRITE;
  twi_slarw |= address << 1;

 

在AVR C库手册中:

R/W bit in SLA+R/W address field.
• #define TW_READ 1
• #define TW_WRITE 0

也就是说,地址其实是加上读写位后转换而来的地址。


另外,找了一下DS3231的文档:


果然如此、



专家
2015-11-05 21:17:32     打赏
20楼

nucleo的RTC续(四)


改写后的代码如下:

#include "mbed.h"

#define DS3231_ADDR   (0x68)
#define TW_READ 1
#define TW_WRITE 0

Serial pc(USBTX,USBRX);
I2C i2c(I2C_SDA, I2C_SCL); 
DigitalOut myled(LED1);

int main()

{
	  char data_write[10];
    char data_read[10];
	
	  data_write[0] = 0x00;
    //data_write[1] = 0x02;
	
		int status ;

		status = i2c.write( (TW_WRITE | DS3231_ADDR <<1) , data_write, 1, 0);
		pc.printf("Return Value:%d\r\n", status);
    if (status != 0) { //NO ACK
				pc.printf("I2C Write status Error\r\n");
    }	 

		
	 status = i2c.read( (TW_READ | DS3231_ADDR <<1), data_read, 7);
	 pc.printf("\r\nReturn Value:%d\r\n", status);
	 if (status != 0) { //NO ACK
				pc.printf("I2C Read status Error\r\n");
    }	 
			 
	 for(int i=0; i<7; i++)
			pc.printf("%x\t", data_read[i]);
				
   pc.printf("\r\nI2C Test End!\r\n");

}


测试结果:

Return Value:0

Return Value:0
26	7	21	4	5	11	15	
I2C Test End!


总算出数啦,累死我啦。

数据依次是:秒,分,小时,星期,日, 月,年

和当前时间完全一致啊,爽得不要不要的。

(数据是BCD编码存储的,我用16进制打印出来就是正确的,年,月和STM32L053R8的定义有些差异,需要注意)


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