I need a help in arduino uno r3 with push button. By using the registers without using the pinMode, digitalWrite, digitalRead if-else, and switch-case.
int led1=2, led2=3, led3=4, led4=5;
int led5=8, led6=9, led7=10, led8=11;
int button=12;
int i,j,k;
void setup() {
DDRB=DDRB|B00001111;
DDRD=DDRD|B00111100;
Serial.begin (9600);
}
void loop() {
int f=0;
for(int s=0;s<16;s++){
int k=0;
int i=0b00001;
int j=0b0011;
PORTB=f;
f +=1;
if (f==64){f=0;}
PORTD=0;
for(k=0;k<7;k++){
delay(250);
PORTD=i;
delay(250);
PORTD=j;
i=(i<<1);
j=(j<<1);
}
j=(j>>1);
for(int d=0; d<9; d++){
delay(250);
PORTD=i;
delay(250);
PORTD=j;
i=(i>>1);
j=(j>>1);
}
}
}
This is the code. That what I need is to make a while loop for the push button. When I will push the button the program will be start and when I push the button again program will stop.
Well, you can do this in 2 way.
First one
The simple one is writing and reading a byte directly into/fom eeprom. Everytime you press the push button, you need to read it first and validate this value. Lets supose your byte means 0 to turned off and 1 to turned on. So if you push the button and the already saved byte is 0, so you need to change this to 1.
You are going to write using this:
https://www.arduino.cc/en/Tutorial/EEPROMWrite
After this management, you will need to read this byte constantly inside your loop statement. If byte is 1, so your thread can be executed.
You are going to read using this: https://www.arduino.cc/en/Tutorial/EEPROMRead
Second
This is a cannon to kill a mosquito, but can be reused later to manage other kinds of informations. You are going to use the same logic, but saving more detailed or complex values. We are talking about some kind of database.
http://playground.arduino.cc/Code/DatabaseLibrary
I'm sorry but I can't write to you a sample code right now. Job first. If you can't do this untill the end of the day, maybe I can come later and comlete this post to help you out.
Related
I have motor programmed with arduino, the hardware is already setup so i don't want to change the micro controller. I need to give the motor 1 second to move from each point to the other and if its too much stay until "one second" is done and then go the rest of the code.
the bellow code this is part of the whole code. it freezes and not working after about 40 hour. please advise how can i prevent that. I know that the mills() function is the problem but don't know whats the best option to replace or prevent that?
unsigned long firsttime = 0;
unsigned long secondtime = 0;
void loop(){
...
firsttime= millis();
myStepper.step(RNum);
secondtime = 1000-millis()+firsttime;
delay (secondtime);
...
}
Thanks
I am new to Arduino, and right now I am trying to generate a frequency that gradually decreases (without using the tone library) in a program that gradually increases the delay between the switching of the high and low. I have the arduino connected to an audio amp and a speaker.
For some reason, the speaker only outputs a single tone and I dont know why. Here is the code:
void setup()
{
pinMode(3, OUTPUT);
}
void loop()
{
for (int i=100; i <= 25500; i+100){
digitalWrite(3, HIGH);
delayMicroseconds(i);
digitalWrite(3, LOW);
delayMicroseconds(i);
}
}
Any help would be appreciated. I would prefer to try and do this the way I am doing, as opposed to using a completly different method or the tone library.
There is an error in the for statement: the increment statement is actually not a statement. You need to assign i to the new value, i.e. write i = i + 100 instead of just i + 100.
I'm a beginner using Arduino with a Teensy 3.2 board and programming it as a usb keyboard.
I have two 4 button membrane switches. Their button contacts are on pins 1-8, and the 9th pin holds a soldered together wire of both membrane switches' "ground" line or whatever it's true name is; the line that completes the circuit.
Basically when you press the buttons they are supposed to simply type "a, b, c..." respectively. I've been told I need to use a matrix for this.
I'm looking for an example of how to code a keyboard matrix that effectively supports a one row/9 column line (or vice versa?) I've been unable to find that solution online.
All I have so far is this code which, when the button on the second pin is pressed, sends tons of "AAAAAAAAAAAAAAAA" keystrokes.
void setup() {
// make pin 2 an input and turn on the
// pullup resistor so it goes high unless
// connected to ground:
pinMode(2, INPUT_PULLUP);
Keyboard.begin();
}
void loop() {
//if the button is pressed
if(digitalRead(2)==LOW){
//Send an ASCII 'A',
Keyboard.write(65);
}
}
Would anyone be able to help?
First of all, a 1-row keypad is NOT a matrix. Or better, technically it can be considered a matrix but... A matrix keypad is something like this:
You see? In order to scan this you have to
Pull Row1 to ground, while leaving rows 2-4 floating
Read the values of Col1-4. These are the values of switches 1-4
Pull Row2 to ground, while leaving rows 1 and 3-4 floating
Read the values of Col1-4. These are the values of switches 5-8
And so on, for all the rows
As for the other problem, you are printing an A when the button is held low. What you want to achieve is to print A only on the falling edge of the pin (ideally once per pressure), so
char currValue = digitalRead(2);
if((currValue==LOW) && (oldValue==HIGH))
{
//Send an ASCII 'A',
Keyboard.write(65);
}
oldValue = currValue;
Of course you need to declare oldValue outside the loop function and initialize it to HIGH in the main.
With this code you won't receive tons of 'A's, but however you will see something like 5-10 'A's every time you press the button. Why? Because of the bouncing of the button. That's what debouncing techniques are for!
I suggest you to look at the class Bounce2 to get an easy to use class for your button. IF you prefer some code, I wrote this small code for another question:
#define CHECK_EVERY_MS 20
#define MIN_STABLE_VALS 5
unsigned long previousMillis;
char stableVals;
char buttonPressed;
...
void loop() {
if ((millis() - previousMillis) > CHECK_EVERY_MS)
{
previousMillis += CHECK_EVERY_MS;
if (digitalRead(2) != buttonPressed)
{
stableVals++;
if (stableVals >= MIN_STABLE_VALS)
{
buttonPressed = !buttonPressed;
stableVals = 0;
if (buttonPressed)
{
//Send an ASCII 'A',
Keyboard.write(65);
}
}
}
else
stableVals = 0;
}
}
In this case there is no need to check for the previous value, since the function already has a point reached only when the state changes.
If you have to use this for more buttons, however, you will have to duplicate the whole code (and also to use more stableVals variables). That's why I suggsted you to use the Bounce2 class (it does something like this but, since it is all wrapped inside a class, you won't need to bother about variables).
I am developing an application in Atmel Studio 6 using the xMega32a4u. I'm using the TWI libraries provided by Atmel. Everything is going well for the most part.
Here is my issue: In order to update an OLED display I am using (SSD1306 controller, 128x32), the entire contents of the display RAM must be written immediately following the I2C START command, slave address, and control byte so the display knows to enter the data into the display RAM. If the control byte does not immediately precede the display RAM package, nothing works.
I am using a Saleae logic analyzer to verify that the bus is doing what it should.
Here is the function I am using to write the display:
void OLED_buffer(){ // Used to write contents of display buffer to OLED
uint8_t data_array[513];
data_array[0] = SSD1306_DATA_BYTE;
for (int i=0;i<512;++i){
data_array[i+1] = buffer[i];
}
OLED_command(SSD1306_SETLOWCOLUMN | 0x00);
OLED_command(SSD1306_SETHIGHCOLUMN | 0x00);
OLED_command(SSD1306_SETSTARTLINE | 0x00);
twi_package_t buffer_send = {
.chip = OLED_BUS_ADDRESS,
.buffer = data_array,
.length = 513
};
twi_master_write(&TWIC, &buffer_send);
}
Clearly, this is very inefficient as each call to this function recreates the entire array "buffer" into a new array "data_array," one element at a time. The point of this is to insert the control byte (SSD1306_DATA_BYTE = 0x40) into the array so that the entire "package" is sent at once, and the control byte is in the right place. I could make the original "buffer" array one element larger and add the control byte as the first element, to skip this process but that makes the size 513 rather than 512, and might mess with some of the text/graphical functions that manipulate this array and depend on it being the correct size.
Now, I thought I could write the code like this:
void OLED_buffer(){ // Used to write contents of display buffer to OLED
uint8_t data_byte = SSD1306_DATA_BYTE;
OLED_command(SSD1306_SETLOWCOLUMN | 0x00);
OLED_command(SSD1306_SETHIGHCOLUMN | 0x00);
OLED_command(SSD1306_SETSTARTLINE | 0x00);
twi_package_t data_control_byte = {
.chip = OLED_BUS_ADDRESS,
.buffer = data_byte,
.length = 1
};
twi_master_write(&TWIC, &data_control_byte);
twi_package_t buffer_send = {
.chip = OLED_BUS_ADDRESS,
.buffer = buffer,
.length = 512
};
twi_master_write(&TWIC, &buffer_send);
}
/*
That doesn't work. The first "twi_master_write" command sends a START, address, control, STOP. Then the next such command sends a START, address, data buffer, STOP. Because the control byte is missing from the latter transaction, this does not work. All I need is to insert a 0x40 byte between the address byte and the buffer array when it is sent over the I2C bus. twi_master_write is a function that is provided in the Atmel TWI libraries. I've tried to examine the libraries to figure out its inner workings, but I can't make sense of it.
Surely, instead of figuring out how to recreate a twi_write function to work the way I need, there is an easier way to add this preceding control byte? Ideally one that is not so wasteful of clock cycles as my first code example? Realistically the display still updates very fast, more than enough for my needs, but that does not change the fact this is inefficient code.
I appreciate any advice you all may have. Thanks in advance!
How about having buffer and data_array pointing to the same uint8_t[513] array, but with buffer starting at its second element. Then you can continue to use buffer as you do today, but also use data_array directly without first having to copy all the elements from buffer.
uint8_t data_array[513];
uint8_t *buffer = &data_array[1];
I'm writing an application that runs an algorithm, but allows you to 'step through' the algorithm by pressing a button - displaying what's happening at each step.
How do I listen for events while within a method?
eg, look at the code I've got.
static int proceed;
button1Event(GtkWidget *widget)
{
proceed = 0;
int i = 0;
for (i=0; i<15; i++) //this is our example 'algorithm'
{
while (proceed ==0) continue;
printf("the nunmber is %d\n", i);
proceed = 0;
}
}
button2Event(GtkWidget *widget)
{
proceed = 1;
}
This doesn't work because it's required to exit out of the button1 method before it can listen for button2 (or any other events).
I'm thinking something like in that while loop.
while(proceed == 0)
{
listen_for_button_click();
}
What method is that?
The "real" answer here (the one any experienced GTK+ programmer will give you) isn't one you will like perhaps: don't do this, your code is structured the wrong way.
The options include:
recommended: restructure the app to be event-driven instead; probably you need to keep track of your state (either a state machine or just a boolean flag) and ignore whichever button is not currently applicable.
you can run a recursive main loop, as in the other answer with gtk_main_iteration(); however this is quite dangerous because any UI event can happen in that loop, such as windows closing or other totally unrelated stuff. Not workable in most real apps of any size.
move the blocking logic to another thread and communicate via a GAsyncQueue or something along those lines (caution, this is hard-ish to get right and likely to be overkill).
I think you are going wrong here:
while(proceed == 0)
{
listen_for_button_click();
}
You don't want while loops like this; you just want the GTK+ main loop doing your blocking. When you get the button click, in the callback for it, then write whatever the code after this while loop would have been.
You could check for pending events & handle the events in while loop in the clicked callback. Something on these lines:
button1Event(GtkWidget *widget)
{
proceed = 0;
int i = 0;
for (i=0; i<15; i++) //this is our example 'algorithm'
{
while (proceed ==0)
{
/* Check for all pending events */
while(gtk_events_pending())
{
gtk_main_iteration(); /* Handle the events */
}
continue;
}
printf("the nunmber is %d\n", i);
proceed = 0;
}
}
This way when the events related click on the second button is added to the event queue to be handled, the check will see the events as pending and handle them & then proceed. This way your global value changes can be reflected & stepping should be possible.
Hope this helps!
If you want to do it like this, the only way that comes to my mind is to create a separate thread for your algorithm and use some synchronization methods to notify that thread from within button click handlers.
GTK+ (glib, to be more specific) has its own API for threads and synchronization. As far as I know Condition variables are a standard way to implement wait-notify logic.