Please give a favor,
I am using MikroC compiler to write a program for 8051 microcontrollers, I am trying to find a way to execute and repeat the main program for 10 seconds, then stop for 2 seconds
Code below just an example, I need to toggle Port two each 200 msec, repeat that for 10 sec, then stop for 2 sec, then repeat this operation.
void main()
{
P2 = 0xAE;
while (1) {
P2 = ~P2;
Delay_ms(200);
}
}
Thank you
You can use a counter to measure the time: For example:
#define MS_PER_TICK 200
#define BLINK_PERIOD_IN_S 10
#define PAUSE_PERIOD_IN_S 2
#define BLINK_PERIOD_IN_TICKS (BLINK_PERIOD_IN_S * 1000 / MS_PER_TICK)
#define PAUSE_PERIOD_IN_TICKS (PAUSE_PERIOD_IN_S * 1000 / MS_PER_TICK)
void main(void) {
unsigned char ticks = 0;
P2 = 0xAE;
for (;;) {
Delay_ms(MS_PER_TICK);
ticks++;
if (ticks <= BLINK_PERIOD_IN_TICKS) {
P2 = ~P2;
}
if (ticks == BLINK_PERIOD_IN_TICKS + PAUSE_PERIOD_IN_TICKS) {
ticks = 0;
}
}
}
Related
I am using LPCXpresso1549 to generate chirp signal with frequency between 35000 Hz and 45000 Hz. First off, I generate DAC chirp samples on matlab, and store them in const uint16_t chirpData[]. The samples frequency is 96000 Hz, therefore 96001 samples. Then, I set the timer to send samples out one by one every (1/96000) second. However, my signal I got having frequency between 3200 Hz to 44000 Hz. Is that because the timer is slow?
enter code here
const uint16_t chirpData[NUM_SAMPLES] = { 2048, ...., 1728, 2048} //96001 sampels
#include "mbed.h"
#include "chirp.h"
Serial pc(USBTX, USBRX);
Timer t;
AnalogOut aout(P0_12);
int main()
{
int i = 0;
while(true) {
// Write the sample to the analog
t.start(); //start timer
if(t.read() >= 0.00001){ // 1/samplef = 0.00001
aout.write_u16(chirpData[i]);
i++;
t.reset(); // reset timer to zero
if(i > 96000) {
i = 0;
}
}
}
}
In this case I recommend you using Threads executing Tasks by:
#define xTaskCreate( pvTaskCode, pcName, usStackDepth, pvParameters, uxPriority, pxCreatedTask ) xTaskGenericCreate( ( pvTaskCode ), ( pcName ), ( usStackDepth ), ( pvParameters ), ( uxPriority ), ( pxCreatedTask ), ( NULL ), ( NULL ) )
xTaskHandle taskHandle;
xTaskCreate(..); //Check Task.h
Then you can set your task cycle by
void your_task() {
unsigned task_cycle_ms = 1/freq; //Careful, convert to ms.
portTickType xLastWakeTime = 0;
portTickType xFrequency = task_cycle_ms/portTICK_RATE_MS;
for(;;) {
vTaskDelayUntil( &xLastWakeTime, xFrequency );
//your code to execute every cycle here
}
}
I have connected the LM35 temperature sensor in analog channel of AN1 then transmitting the temperature through serial RS232 in PIC16F887. I have read the temperature value but the value is frequently varying as 31 and 32, also when touch the LM35 temperature is varying very fast as 32, 33 and etc. How to control the constant temperature value. Here is my code, Please any one help me.
#include <htc.h>
void main(void)
{
TRISA1 = 1;
ANS1 = 1;
OSCCON = 0x78; // OSCILLATOR CONTROL REGISTER
TXSTA = 0x26;
RCSTA = 0x90;
SPBRG = 10;
ADCON1 = 0x80;
unsigned int current_temp, initial_temp = temperature();
transmit_char(initial_temp);
flag = 0;
while (1)
{
current_temp = temperature();
if((current_temp == (initial_temp + 1)) || (current_temp == (initial_temp - 1)))
{
flag = 1;
}
if(flag == 1)
{
flag = 0;
transmit_char(current_temp);
initial_temp = current_temp;
}
}
}
int temperature(void)
{
ADCON0 = 0xC5;
GODONE = 1;
while(GODONE);
int temp;
temp = (ADRESH << 8) + ADRESL;
temp = temp/2;
return temp;
}
Do this,
Collect ten adc data,
Remove min and max from that values.
sum the remaining 8 ADC values and divide the value by 8.
this should be continuous process, average for every ten samples
note: sampling and averaging should be ... 1 to 10 , next 2 to 11 and 3 to 12. at every reading you will get the adc value. sudden fluctuations also get filtered here.
Hope this helps.. good luck..
I'm working on a project where I want to ramp the pwm duty cycle from 0 to 50%. My period is 16000 counts or 1ms (16MHz default timer count). For some reason, instead of updating the duty cycle each period, it updates it much slower. I wonder if it's because I'm calculating the new duty cycle within the timer interrupt? Here's what I'm using:
void TIM4_IRQHandler()
{
if (TIM_GetITStatus(TIM4, TIM_IT_Update) != RESET)
{
TIM_ClearITPendingBit(TIM4, TIM_IT_Update);
if (loop <= 8000) {
TIM4 -> CCR1 = CCR_i;
uint16_t y = CCR_i;
CCR_i = y + 1;
int x = loop;
loop = x + 1;
}
if (loop == 8001) {
TIM4 -> CCR1 = 0;
uint16_t x = CCR_i;
CCR_i = x + 1;
int c = loop;
loop = c + 1;
}
if (loop > 8001) {
int t;
for(t = 0; t < 10; t++){
// wait
}
GPIO_SetBits(GPIOG, GPIO_Pin_8);
//Stop2();
TIM_ITConfig(TIM4, TIM_IT_Update, DISABLE);
NVIC_DisableIRQ(TIM4_IRQn);
}
}
}
blast, it looks like I was being silly - the timer is doing exactly what I want it to - it just takes 8 seconds with a period of 1ms to ramp to a pulsewidth of 500us adding 62.5ns per period.
#using <mscorlib.dll>
#using <System.dll>
using namespace System;
using namespace System::Text;
using namespace System::IO;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Collections;
Errors: IntelliSense: "#using" requires C++/CLI to be enabled....
how to fix this prob!?
Your project settings are wrong. Specifically Configuration Properties, General, Common Language Runtime support.
Fall in the pit of success by starting your project by picking one of the project templates in the CLR node.
Choose Project -> Properties from the menu bar. In the Project properties window, under Configuration Properties -> General, make sure that Common Language Runtime Support is set to Common Language Runtime Support (/clr)
In VS2019 it the steps would be :
1/ Right click on the project
2/ Project
3/ Properties
4/ Configuration Properties
5/ Advanced
6/ Common Language Runtime Support change it to Common Language Runtime Support(/clr)
Enable it in your project settings (right click on the projet -> settings) the first tab should provide the option.
The MSDN has a nice example for testing the difference in performance, Parse vs tryParse:
Stopwatch Example
#include <stdio.h>
#using <System.dll>
using namespace System;
using namespace System::Diagnostics;
void DisplayTimerProperties()
{
// Display the timer frequency and resolution.
if (Stopwatch::IsHighResolution)
{
Console::WriteLine("Operations timed using the system's high-resolution performance counter.");
}
else
{
Console::WriteLine("Operations timed using the DateTime class.");
}
Int64 frequency = Stopwatch::Frequency;
Console::WriteLine(" Timer frequency in ticks per second = {0}", frequency);
Int64 nanosecPerTick = (1000L * 1000L * 1000L) / frequency;
Console::WriteLine(" Timer is accurate within {0} nanoseconds", nanosecPerTick);
}
void TimeOperations()
{
Int64 nanosecPerTick = (1000L * 1000L * 1000L) / Stopwatch::Frequency;
const long numIterations = 10000;
// Define the operation title names.
array<String^>^operationNames = { "Operation: Int32.Parse(\"0\")","Operation: Int32.TryParse(\"0\")","Operation: Int32.Parse(\"a\")","Operation: Int32.TryParse(\"a\")" };
// Time four different implementations for parsing
// an integer from a string.
for (int operation = 0; operation <= 3; operation++)
{
// Define variables for operation statistics.
Int64 numTicks = 0;
Int64 numRollovers = 0;
Int64 maxTicks = 0;
Int64 minTicks = Int64::MaxValue;
int indexFastest = -1;
int indexSlowest = -1;
Int64 milliSec = 0;
Stopwatch ^ time10kOperations = Stopwatch::StartNew();
// Run the current operation 10001 times.
// The first execution time will be tossed
// out, since it can skew the average time.
for (int i = 0; i <= numIterations; i++)
{
Int64 ticksThisTime = 0;
int inputNum;
Stopwatch ^ timePerParse;
switch (operation)
{
case 0:
// Parse a valid integer using
// a try-catch statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch::StartNew();
try
{
inputNum = Int32::Parse("0");
}
catch (FormatException^)
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse->Stop();
ticksThisTime = timePerParse->ElapsedTicks;
break;
case 1:
// Parse a valid integer using
// the TryParse statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch::StartNew();
if (!Int32::TryParse("0", inputNum))
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse->Stop();
ticksThisTime = timePerParse->ElapsedTicks;
break;
case 2:
// Parse an invalid value using
// a try-catch statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch::StartNew();
try
{
inputNum = Int32::Parse("a");
}
catch (FormatException^)
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse->Stop();
ticksThisTime = timePerParse->ElapsedTicks;
break;
case 3:
// Parse an invalid value using
// the TryParse statement.
// Start a new stopwatch timer.
timePerParse = Stopwatch::StartNew();
if (!Int32::TryParse("a", inputNum))
{
inputNum = 0;
}
// Stop the timer, and save the
// elapsed ticks for the operation.
timePerParse->Stop();
ticksThisTime = timePerParse->ElapsedTicks;
break;
default:
break;
}
// Skip over the time for the first operation,
// just in case it caused a one-time
// performance hit.
if (i == 0)
{
time10kOperations->Reset();
time10kOperations->Start();
}
else
{
// Update operation statistics
// for iterations 1-10001.
if (maxTicks < ticksThisTime)
{
indexSlowest = i;
maxTicks = ticksThisTime;
}
if (minTicks > ticksThisTime)
{
indexFastest = i;
minTicks = ticksThisTime;
}
numTicks += ticksThisTime;
if (numTicks < ticksThisTime)
{
// Keep track of rollovers.
numRollovers++;
}
}
}
// Display the statistics for 10000 iterations.
time10kOperations->Stop();
milliSec = time10kOperations->ElapsedMilliseconds;
Console::WriteLine();
Console::WriteLine("{0} Summary:", operationNames[operation]);
Console::WriteLine(" Slowest time: #{0}/{1} = {2} ticks", indexSlowest, numIterations, maxTicks);
Console::WriteLine(" Fastest time: #{0}/{1} = {2} ticks", indexFastest, numIterations, minTicks);
Console::WriteLine(" Average time: {0} ticks = {1} nanoseconds", numTicks / numIterations, (numTicks * nanosecPerTick) / numIterations);
Console::WriteLine(" Total time looping through {0} operations: {1} milliseconds", numIterations, milliSec);
}
}
int main()
{
DisplayTimerProperties();
Console::WriteLine();
Console::WriteLine("Press the Enter key to begin:");
Console::ReadLine();
Console::WriteLine();
TimeOperations();
getchar();
}
//Operations timed using the system's high-resolution performance counter.
//Timer frequency in ticks per second = 3319338
//Timer is accurate within 301 nanoseconds
//
//Press the Enter key to begin :
//
//
//
//Operation : Int32.Parse("0") Summary :
// Slowest time : #4483 / 10000 = 95 ticks
// Fastest time : #3 / 10000 = 0 ticks
// Average time : 0 ticks = 99 nanoseconds
// Total time looping through 10000 operations : 1 milliseconds
//
// Operation : Int32.TryParse("0") Summary :
// Slowest time : #7720 / 10000 = 187 ticks
// Fastest time : #1 / 10000 = 0 ticks
// Average time : 0 ticks = 109 nanoseconds
// Total time looping through 10000 operations : 1 milliseconds
//
// Operation : Int32.Parse("a") Summary :
// Slowest time : #3701 / 10000 = 2388 ticks
// Fastest time : #2698 / 10000 = 102 ticks
// Average time : 116 ticks = 35109 nanoseconds
// Total time looping through 10000 operations : 352 milliseconds
//
// Operation : Int32.TryParse("a") Summary :
// Slowest time : #8593 / 10000 = 23 ticks
// Fastest time : #1 / 10000 = 0 ticks
// Average time : 0 ticks = 88 nanoseconds
// Total time looping through 10000 operations : 1 milliseconds
If you are using Visual Studio, you might have to do some installations pre-hand. To install those, open the Visual Studio Installer from the Windows Start menu. Make sure that the Desktop development with C++ tile is checked, and in the Optional components section, also check C++/CLI Support.
I have to Create a dynamic array capable of holding 2*n Fractions.
If the dynamic array cannot be allocated, prints a message and calls exit(1).
It next fills the array with reduced random Fractions whose numerator
is between 1 and 20, inclusive; and whose initial denominator
is between 2 and 20, inclusive.
I ready did the function that is going to create the fraction and reduced it. this is what I got. When I compiled and run this program it crashes I cant find out why. If I put 1 instead of 10 in the test.c It doesn't crash but it gives me a crazy fraction. If I put 7,8,or 11 in the test.c it will crash. I would appreciate if someone can help me.
FractionSumTester.c
Fraction randomFraction(int minNum, int minDenom, int max)
{
Fraction l;
Fraction m;
Fraction f;
l.numerator = randomInt(minNum, max);
l.denominator = randomInt(minDenom, max);
m = reduceFraction(l);
while (m.denominator <= 1)
{
l.numerator = randomInt(minNum, max);
l.denominator = randomInt(minDenom, max);
m = reduceFraction(l);
}
return m;
}
Fraction *createFractionArray(int n)
{
Fraction *p;
int i;
p = malloc(n * sizeof(Fraction));
if (p == NULL)
{
printf("error");
exit(1);
}
for(i=0; i < 2*n ; i++)
{
p[i] = randomFraction(1,2,20);
printf("%d/%d\n", p[i].numerator, p[i].denominator);
}
return p;
}
this is the what I am using to test this two functions.
test.c
#include "Fraction.h"
#include "FractionSumTester.h"
#include <stdio.h>
int main()
{
createFractionArray(10);
return 0;
}
In your createFractionArray() function, you malloc() space for n items. Then, in the for loop, you write 2*n items into that space... which overruns your buffer and causes the crash.