COleDateTime - C / C++ / MFC Discussion Boards

Re: InitDialog in splitter

David Crow29-Mar-16 9:11

David Crow

29-Mar-16 9:11

Member 12282738 wrote:
...I don't know where to place the call to oglInitalize()

See here.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

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arduino sensor

Member 1240312128-Mar-16 7:35

Member 12403121

28-Mar-16 7:35

Hello,

I am having trouble with my current project and need your help.
Weight sensor is is connected to arduino uno board and to several light sources.
goal is: sensor activated-mode1, sensor unactive-mode 2 for 5 seconds.
Mode 1 is blinking light and mode 2 is normal light.
I have written code sensor activation, for mode1 and mode 2 but it cant get it to work. What im i missing?

sensor :
(www.elecrow.com/weight-sensor-kit-3kg-p-883.html)

code:
sensor activation:

#include <Hx711.h>

#define LED 6
#define ADC1 A2
#define ADC2 A3
#define THRESHOLD 100.

Hx711 scale(ADC1, ADC2);

void setup() {
pinMode(LED, OUTPUT);
}

void loop() {
digitalWrite(LED, HIGH);
delay(500);
if(scale.getGram() > THRESHOLD)
digitalWrite(LED, LOW);
delay(500);
}

mod1 blinking

int led = 13;

void setup() {
pinMode(led, OUTPUT);
}

void loop() {
digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level)
delay(500); // wait
digitalWrite(led, LOW); // turn the LED off by making the voltage LOW
delay(500); // wait
}

mod 2 light for 5 sec

int led = 13;

void setup() {
pinMode(led, OUTPUT);
}

void loop() {
digitalWrite(led, HIGH);
delay(0);
digitalWrite(led, LOW);
delay(5000);
}

Re: arduino sensor

David Crow28-Mar-16 9:40

David Crow

28-Mar-16 9:40

Member 12403121 wrote:
What im i missing?

The correct forum, perhaps.

Re: arduino sensor

Richard MacCutchan28-Mar-16 21:44

Richard MacCutchan

28-Mar-16 21:44

The above code means very little. Please explain exactly what the problem is. If necessary use your debugger to capture more information.

Re: arduino sensor

Sascha Lefèvre28-Mar-16 23:31

Sascha Lefèvre

28-Mar-16 23:31

Member 12403121 wrote:
but it cant get it to work

Does it compile? If not, what's the compiler error message?
Or if it does at least partially work, what does work, what does not?

If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

Re: arduino sensor

Member 1240312130-Mar-16 23:19

Member 12403121

30-Mar-16 23:19

Hi,
Sorry for not beening specific, i am new to this.
the problem is the first part of the code, one for interact with sensor. I dont know how to write it. This is my best try... it is modification of several examples. I was hoping for some advices.
code for mode 1 and 2 work Just fine i Just cant connect it all for sensor to recognize.
hope i explain it better tjan last time

Re: arduino sensor

leon de boer3-Apr-16 6:43

leon de boer

3-Apr-16 6:43

The only thing I can see change between the two modes is the delay

C++

// COMBINED MODE 1 & 2 CODE FROM WHAT YOU GAVE

int led = 13;
int mode = 1;                     //  Set mode 1 start                  
static int delay1[2] = {500, 0};  // 500ms delay for mode 1, 0 ms delay for mode 2
static int delay2[2] = {500, 5000};  // 500ms delay for mode 1, 5000 ms delay for mode 2

void setup() {
pinMode(led, OUTPUT);
}

void loop() {
digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level)
delay(delay1[mode-1]);   // wait depending on mode .. dont forget arrays start at zero in c
digitalWrite(led, LOW);  // turn the LED off by making the voltage LOW
delay(delay2[mode-1]);   // wait depending on mode .. dont forget arrays start at zero in c

// this is just to show off both modes usually something does this change  
// this code simple forces alternation between the 2 modes
if (mode == 1) mode = 2; else mode = 1;
}

In vino veritas

COleDateTime

Still learning how to code27-Mar-16 9:48

Still learning how to code

27-Mar-16 9:48

I have an application in which time values are transferred byte-by-byte to an Arduino via USB/COM. I have now realised that using CTime objects will suffer from the 19 January 2038 problem where, after this date, GetTime() will return negative values due to the return value being signed. It appears that use of COleDateTime with CTimeSpan ::GetTotalSeconds will avoid this as the return value is an unsigned quantity.
I have now written a bit of test code comparing CTime and the ColeDateTime. /CtimeSpan combination. Whilst the values returned by the various member functions (year, month, etc,etc) all give identical values, the GetTime() and GetTotalSeconds() values differ by 3600 (1 hour)

Here is my test code:-

// ----------------------- CTime operations -------------------------
CTime tNow;
tNow = CTime::GetCurrentTime();	

int iTimeYear = tNow.GetYear(); 
int iTimeMonth = tNow.GetMonth();
int iTimeDay = tNow.GetDay();
int iTimeHour = tNow.GetHour();
int iTimeMinute = tNow.GetMinute();
int iTimeSecond = tNow.GetSecond();

unsigned long ulNow = tNow.GetTime();

// ----------- COleDateTime / CTimeSpan operations  ----------
COleDateTime epoch(1970,1,1,0,0,0);	// 1970 Jan 1 midnight 
COleDateTime tCurrentTime;
tCurrentTime = COleDateTime::GetCurrentTime();

int iOleYear = tCurrentTime.GetYear();
int iOleMonth = tCurrentTime.GetMonth();
int iOleDay = tCurrentTime.GetDay();	
int iOleHour = tCurrentTime.GetHour();
int iOleMinute = tCurrentTime.GetMinute();
int iOleSecond = tCurrentTime.GetSecond();

unsigned long ulOleTime = (unsigned long)(tCurrentTime-epoch).GetTotalSeconds();

Doug

Re: COleDateTime

Serkan Onat27-Mar-16 12:44

Serkan Onat

27-Mar-16 12:44

one hour difference between CTime and COleDateTime is because COleDateTime ignores daylight saving time

i would not care much about 2038, because today's code will be antique at that time

if these time values will be shared across multiple devices then i would use CRT functions

C++

time_t now = time(NULL);

Re: COleDateTime

Still learning how to code27-Mar-16 22:11

Still learning how to code

27-Mar-16 22:11

Hi Serkan,
I thought that originally, but COleDateTime MUST be taking account of DST as the GetHour() function returns the correct value. Thinking about it overnight, I'm beginning to think that I should have applied DST when generating epoch - that would fit the symptoms, wouldn't it ?
(The Arduino works with an unsigned quantity, so it will not be a problem !)

After thought:-
I now believe that the problem is due to taking the DIFFERENCE between Current Time and epoch (I actually got this code off the internet, but didn't do much thinking about it !!!) If DST is applied inherently to all OleDateTime objects, then taking the difference effectively removes any adjustment due to DST, So that would account for it for GetTime() and GetTotalSeconds() being 3600 seconds different !!

Doug

modified 28-Mar-16 5:01am.

Re: COleDateTime

Jochen Arndt28-Mar-16 1:50

Jochen Arndt

28-Mar-16 1:50

ColeDateTime stores a time stamp value without information about time zone and DST. It is up to you to know if the value is local time or UTC. If you use COleDateTime::GetCurrentTime to initialise it, it will hold a local time value. If you use the constructor or assignment operator accepting a time_t or _time64_t value, it will be UTC when the time_t value has been retrieved using time() and not adjusted afterwards.

If you need to store time stamp values for later use, store them as UTC. This avoids wrong values and simplifies calculation of time spans. If you need to display times as local times, perform the conversion just before display.

See also Time Format Conversion Made Easy[^] here at CP.

Re: COleDateTime

Still learning how to code28-Mar-16 22:58

Still learning how to code

28-Mar-16 22:58

Hello Jochen, I was not aware that the timestamp obtained from COleDateTime would depend on how the object was initialised. Therefore in my test code the object epoch would result in a UTC value, whereas that obtained from the other object (which initialised via GetCurrentTime()) would be localtime. This then blows my "difference" explanation as to why the result from CTime is 3600 seconds different from the COleDateTimeSpan object. My Arduino code expects time quantities to be received as localtime (i.e. adjusted for DST)

Doug

Re: COleDateTime

Jochen Arndt28-Mar-16 23:08

Jochen Arndt

28-Mar-16 23:08

Still learning how to code wrote:
My Arduino code expects time quantities to be received as localtime (i.e. adjusted for DST)

You should change that to UTC if possible. When your Arduino uses a different time zone than your Windows system, the results would be wrong again.

Old code

RomTibi27-Mar-16 9:18

RomTibi

27-Mar-16 9:18

Reviewing some old projects I met a function like this:

C++

bool func()
{
    bool var = false;

    if(...)
        return var = false;
    else
        return var = true;
}

Actually what the function returns? I think true, because assigning can't be false.

VII. 36. When you surround an army, leave an outlet free. Do not press a desperate foe too hard.
SUN-TZU - Art of War

Re: Old code

Patrice T27-Mar-16 10:46

Patrice T

27-Mar-16 10:46

RomTibi wrote:
Actually what the function returns? I think true, because assigning can't be false.

There is an easy way to know !
- make a program that will execute that code.

Patrice

“Everything should be made as simple as possible, but no simpler.” Albert Einstein

Re: Old code

Sascha Lefèvre27-Mar-16 12:38

Sascha Lefèvre

27-Mar-16 12:38

Any assignment is also an expression which has the value of the assigned value.

C++

if(...)
    return var = false;  // returns false
else
    return var = true;  // returns true

Some programmers make use of this fact like this:

C++

int x;
while ((x = SomeFunction()) > 0)
{
   // use x for something..
}

Whether or not this is good style is up to personal preference..

If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

Re: Old code

David Crow28-Mar-16 3:55

David Crow

28-Mar-16 3:55

RomTibi wrote:
I think true, because assigning can't be false.

True (regardless).

Re: Old code

Richard MacCutchan28-Mar-16 6:08

Richard MacCutchan

28-Mar-16 6:08

Try it.

Re: Old code

Richard MacCutchan28-Mar-16 6:03

Richard MacCutchan

28-Mar-16 6:03

RomTibi wrote:
because assigning can't be false.

Of course it can. This is easy to test by writing a few lines of code.

Algorithm on secrete key generation

Durga Prasad Chauhan25-Mar-16 23:32

Durga Prasad Chauhan

25-Mar-16 23:32

Adam works in the in networking security cell. He wants to generate secret keys
following a pattern. The pattern consists of the characters X and Y.
where X means increasing and Y means decreasing. Help him devise an
algorithm to generate the secret key which is the minimum number encoded
following that pattern. Digits from 1-9 and digits can’t repeat.

Sample Input:                                   Sample Output:

X                                                   12
YXYX                                             21435
YYXYYXXY                                    321654798

Re: Algorithm on secrete key generation

Richard MacCutchan26-Mar-16 1:32

Richard MacCutchan

26-Mar-16 1:32

Sorry, we do not do your homework.

Re: Algorithm on secrete key generation

Patrice T27-Mar-16 10:31

Patrice T

27-Mar-16 10:31

We don't do your HomeWork.
Advice try to solve the problem by habd, see how you build the solution.
try to device a program that will follow the same processus.
It is not so difficult.

Patrice

“Everything should be made as simple as possible, but no simpler.” Albert Einstein

vector in turbo c

Ravinder Singh25-Mar-16 20:50

Ravinder Singh

25-Mar-16 20:50

i know nothing about vector in c. if anyone could provide me link of it n also if someone could give me brief intro i will be obliged

Re: vector in turbo c

Richard MacCutchan25-Mar-16 22:46

Richard MacCutchan

25-Mar-16 22:46

There is no vector in C, do you mean vector stl - Google Search[^]?

Re: vector in turbo c

Patrice T27-Mar-16 10:18

Patrice T

27-Mar-16 10:18

There is no vector in C !
Just arrays.

Advice read C documentation.

Patrice

“Everything should be made as simple as possible, but no simpler.” Albert Einstein

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