I have a problem with showing numbers on the LCD screen in Tinkercad. The time is counting down from 60 seconds. But when it counts until 9-1 the number has shown as 90-10. Eg: LCD screen shows 20 at 2 seconds instead of 02 or 2 only. May I know how can I change it to only 1 digit or 09-01? Hope someone can help me with this. Thanks in advance.
Here my code for Arduino of LCD:
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup()
{
lcd.begin(16, 2); // Set up the number of columns and rows on the LCD.
// Print a message to the LCD.
lcd.print("Ambulance is approaching!");
}
void loop()
{
// set the cursor to column 0, line 1
// (note: line 1 is the second row, since counting
// begins with 0):
lcd.setCursor(0,1);
// Print a message to the LCD.
lcd.print("Time:");
for (int seconds = 60; seconds > 0; --seconds){
lcd.setCursor(6,1);
lcd.print(seconds-1);
delay(1000);
}
}
This is because lcd.print only overwrites the necessary characters. So after displaying 11 it overwrites it with a 10 correctly. After that it overwrites the 1 with a 9 and the 0 stays because the new input is only one character long.
You can clear the line by printing a string containing two spaces and then print the time.
for (int seconds = 60; seconds > 0; --seconds){
lcd.setCursor(6,1);
lcd.print(" ");
lcd.setCursor(6,1);
lcd.print(seconds-1);
delay(1000);
}
Related
I am creating my own version of a music visualizer that responds to the frequency of music; a common project. I am using 2 strips of Neopixels, each with 300 LEDs making a total of 600 LEDs.
I have written functions, shown below, that create the desired affect of having a pulse of light travel down the strips independently. However, when running in real time with music, the updates per second is too slow to create a nice pulse; it looks choppy.
I believe the problem is the number of operations that must be preformed when the function is called. For each call to the function, a 300 value array per strip must be shifted 5 indices and 5 new values added.
Here is an illustration of how the function currently works:
-Arbitrary numbers are used to fill the array
-A shift of 2 indices shown
-X represents an index with no value assigned
-N represents the new value added by the function
Initial array: [1][3][7][2][9]
Shifted array: [X][X][1][3][7]
New array: [N][N][1][3][7]
Here if my code. Function declarations below loop(). I am using random() to trigger a pulse for testing purposes; no other functions were included for brevity.
#include <FastLED.h>
// ========================= Define setup parameters =========================
#define NUM_LEDS1 300 // Number of LEDS in strip 1
#define NUM_LEDS2 300 // Number of LEDS in strip 1
#define STRIP1_PIN 6 // Pin number for strip 1
#define STRIP2_PIN 10 // Pin number for strip 2
#define s1Band 1 // String 1 band index
#define s2Band 5 // String 2 band index
#define numUpdate 5 // Number of LEDs that will be used for a single pulse
// Colors for strip 1: Band 2 (Index 1)
#define s1R 255
#define s1G 0
#define s1B 0
// Colors for strip 2: Band 6 (Index 5)
#define s2R 0
#define s2G 0
#define s2B 255
// Create the arrays of LEDs
CRGB strip1[NUM_LEDS1];
CRGB strip2[NUM_LEDS2];
void setup() {
FastLED.addLeds<NEOPIXEL, STRIP1_PIN>(strip1, NUM_LEDS1);
FastLED.addLeds<NEOPIXEL, STRIP2_PIN>(strip2, NUM_LEDS2);
FastLED.setBrightness(10);
FastLED.clear();
FastLED.show();
}
void loop() {
int num = random(0, 31);
// Pulse strip based on random number for testing
if (num == 5) {
pulseDownStrip1();
}
pulseBlack1();
}
// ======================= FUNCTION DECLARATIONS =======================
// Pulse a set of colored LEDs down the strip
void pulseDownStrip1() {
// Move all current LED states by n number of leds to be updated
for (int i = NUM_LEDS1 - 1; i >= 0; i--) {
strip1[i] = strip1[i - numUpdate];
}
// Add new LED values to the pulse
for (int j = 0; j < numUpdate; j++) {
strip1[j].setRGB(s1R, s1G, s1B);
}
FastLED.show();
}
// Pulse a set of black LEDs down the strip
void pulseBlack1(){
// Move all current LED states by n number of leds to be updated
for (int i = NUM_LEDS1 - 1; i >= 0; i--) {
strip1[i] = strip1[i - numUpdate];
}
// Add new LED values to the pulse
for (int j = 0; j < numUpdate; j++) {
strip1[j].setRGB(0, 0, 0);
}
FastLED.show();
}
I am looking for any suggestions regarding optimizing this operation. Through my research, copying the desired values to a new array rather than shifting the existing array seems to be a faster operation.
If you have any advice on optimizing this process, or alternate methods to produce the same animation, I would appreciate the help.
The secret is to not shift it. Shift where you start reading it instead. Keep track of a separate variable that keeps the start position and alter your reading through the array to start there, roll back over to zero when it gets to the array length, and stop one short of where it starts.
Google the term "circular buffer" Look at the Arduino HardwareSerial class for a decent implementation example.
I have a very large text file (3gb) of data in a simple list in the format:
NEW
2016-08-15_20-45-47-3120
0
0
0
0
1960
0
0
Every new data entry is started by "NEW" then followed by the date stamp and 456 numbers.
I'd like to transform it into a format like:
New 2016-08-15_20-45-47-3120 0 190 0 300
New 2016-08-15_20-45-47-3140 0 0 0 0
New 2016-08-15_20-45-47-3620 1 34 4 76
I'd normally offset it in excel first but with such a large data set it can't begin to cope so it's got to be done in SQL.
Thanks
This is the kind of thing I find awk useful for.
This script captures every line it sees into an array, which it outputs and resets every time it sees the line containing NEW (or the end of file). If you save this code to transpose.awk, it can be run with awk -f transpose.awk big.txt > out.txt.
function output(a,n, i)
{
if(n > 0)
{
for(i = 0; i < n; i++) {
printf "%s\t", a[i];
}
printf "\n";
}
}
/^NEW/ { output(a,n); n=0; delete a; }
{ a[n++] = $0; }
END { output(a,n); }
If you wanted to only output the first 5 columns instead of all 8, you could change the for loop to stop earlier.
I tested this with a 224M dummy sample file and it took 44 seconds on my computer, so 3GB should take roughly ten minutes. Not fast, but bearable.
this program reads text files, and in this case, reads this one:
Sam
5 0 0 0
Dave
5 5 0 0
Bill
5 -5 0 0
Louise
3 3 5 0
Early in my program, I execute the following while loop:
int count = 0;
while (input.hasNextLine())
{
count++;
if (count % 2 == 1) //for every other line, reads the name
{
String line = input.nextLine();
names.add(line); //puts name into array
}
if (count % 2 == 0) //for every other line, reads the ratings
{
ArrayList<Integer> rtemp = new ArrayList<Integer>();
while (input.hasNextInt())
{
int tempInt = input.nextInt();
rtemp.add(tempInt);
}
allratings.add(rtemp);
}
}
For some reason, by the time this while loop is done, int count is at 14. I only want it to be at 8, and think that it should be, considering that there are only 8 lines of text, and it is supposed to execute for each line. Obviously, this causes big problems later in the program. Any idea what is going on?
It seems from your second loop, the cursor never moves to the next line...I added below lines just after your allratings.add(rtemp); and it worked.
if(input.hasNext())
input.next();
I've been looking for some simple coding challenges recently, and discovered about Pascal's triangle (here), and I've tried to generate one myself in C/Objective-C. For those that don't know what it is, that link explains it pretty well.
I'm starting to get oddness after the fourth row, and I just can't figure out why.
My output for 5 iterations currently looks like this:
1
1 1
1 2 1
1 3 3 1
4 6 3 1
It should look like this:
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
Here is my code so far. The first loop is just a reset loop (setting all the values to 0). The actual logic happens mostly in the second loop. The third loop is where the values are concatenated and formatted in a string.
I've commented this code much more than I would for myself just to aid readability.
int iterations, i, b, mid, chars, temp;
NSLog(#"Please enter the number of itereations");
scanf("%i",&iterations); // take users input and store it in iterations
// calculate where the first 1 should go.
if (iterations % 2 == 0) mid = (iterations)/2;
else mid = (iterations+1)/2;
chars = iterations*2;
int solutions[iterations][chars];
// reset loop
for (i = 0; i<iterations; i++) {
for (b = 0; b<chars; b++) {
solutions[i][b] = 0;
}
}
solutions[0][mid] = 1; // place the initial 1 in first row
for (int row = 1; row<iterations; row++) {
for (int chi = 0; chi<chars; chi++) {
temp = 0;
if (chi > 0) {
temp += solutions[row-1][chi-1]; // add the one diagonally left
}
if (chi < iterations) {
temp += solutions[row-1][chi+1]; // add the one diagonally right
}
solutions[row][chi] = temp; // set the value
}
}
// printing below...
NSMutableString *result = [[NSMutableString alloc] initWithString:#"\n"];
NSMutableString *rowtmp;
for (i = 0; i<iterations; i++) {
rowtmp = [NSMutableString stringWithString:#""];
for (b = 0; b<chars; b++) {
if (solutions[i][b] != 0) [rowtmp appendFormat:#"%i",solutions[i][b]];
else [rowtmp appendString:#" "]; // replace any 0s with spaces.
}
[result appendFormat:#"%#\n",rowtmp];
}
NSLog(#"%#",result);
[result release];
I have a feeling the problem may be to do with the offset, but I have no idea how to fix it. If anyone can spot where my code is going wrong, that would be great.
It appears (from a brief look) that the original midpoint calculation is incorrect. I think it should simply be:
mid = iterations - 1;
In the example of 5 iterations, the midpoint needs to be at array position 4. Each iteration "moves" one more position to the left. The 2nd iteration (2nd row) would then place a 1 at positions 3 and 5. The 3rd iteration at 2 and 6. The 4th at 1 and 7. And the 5th and last iteration would fill in the 1s at 0 and 8.
Also, the second if statement for the temp addition should be as follows otherwise it reads past the end of the array bounds:
if (chi < iterations - 1) {
Hi all I am having a strange issue, when i use scanf to input data it repeats strings and saves them as one i am not sure why.
Please Help
/* Assment Label loop - Loops through the assment labels and inputs the percentage and the name for it. */
i = 0;
j = 0;
while (i < totalGradedItems)
{
scanf("%s%d", assLabel[i], &assPercent[i]);
i++;
}
/* Print Statement */
i = 0;
while (i < totalGradedItems)
{
printf("%s", assLabel[i]);
i++;
}
Input Data
Prog1 20
Quiz 20
Prog2 20
Mdtm 15
Final 25
Output Via Console
Prog1QuizQuizProg2MdtmMdtmFinal
Final diagnosis
You don't show your declarations...but you must be allocating just 5 characters for the strings:
When I adjust the enum MAX_ASSESSMENTLEN from 10 to 5 (see the code below) I get the output:
Prog1Quiz 20
Quiz 20
Prog2Mdtm 20
Mdtm 15
Final 25
You did not allow for the terminal null. And you didn't show us what was causing the bug! And the fact that you omitted newlines from the printout obscured the problem.
What's happening is that 'Prog1' is occupying all 5 bytes of the string you read in, and is writing a null at the 6th byte; then Quiz is being read in, starting at the sixth byte.
When printf() goes to read the string for 'Prog1', it stops at the first null, which is the one after the 'z' of 'Quiz', producing the output shown. Repeat for 'Prog2' and 'Mtdm'. If there was an entry after 'Final', it too would suffer. You are lucky that there are enough zero bytes around to prevent any monstrous overruns.
This is a basic buffer overflow (indeed, since the array is on the stack, it is a basic Stack Overflow); you are trying to squeeze 6 characters (Prog1 plus '\0') into a 5 byte space, and it simply does not work well.
Preliminary diagnosis
First, print newlines after your data.
Second, check that scanf() is not returning errors - it probably isn't, but neither you nor we can tell for sure.
Third, are you sure that the data file contains what you say? Plausibly, it contains a pair of 'Quiz' and a pair of 'Mtdm' lines.
Your variable j is unused, incidentally.
You would probably be better off having the input loop run until you are either out of space in the receiving arrays or you get a read failure. However, the code worked for me when dressed up slightly:
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
char assLabel[10][10];
int assPercent[10];
int i = 0;
int totalGradedItems = 5;
while (i < totalGradedItems)
{
if (scanf("%9s%d", assLabel[i], &assPercent[i]) != 2)
{
fprintf(stderr, "Error reading\n");
exit(1);
}
i++;
}
/* Print Statement */
i = 0;
while (i < totalGradedItems)
{
printf("%-9s %3d\n", assLabel[i], assPercent[i]);
i++;
}
return 0;
}
For the quoted input data, the output results are:
Prog1 20
Quiz 20
Prog2 20
Mdtm 15
Final 25
I prefer this version, though:
#include <stdio.h>
enum { MAX_GRADES = 10 };
enum { MAX_ASSESSMENTLEN = 10 };
int main(void)
{
char assLabel[MAX_GRADES][MAX_ASSESSMENTLEN];
int assPercent[MAX_GRADES];
int i = 0;
int totalGradedItems;
for (i = 0; i < MAX_GRADES; i++)
{
if (scanf("%9s%d", assLabel[i], &assPercent[i]) != 2)
break;
}
totalGradedItems = i;
for (i = 0; i < totalGradedItems; i++)
printf("%-9s %3d\n", assLabel[i], assPercent[i]);
return 0;
}
Of course, if I'd set up the scanf() format string 'properly' (meaning safely) so as to limit the length of the assessment names to fit into the space allocated, then the loop would stop reading on the second attempt:
...
char format[10];
...
snprintf(format, sizeof(format), "%%%ds%%d", MAX_ASSESSMENTLEN-1);
...
if (scanf(format, assLabel[i], &assPercent[i]) != 2)
With MAX_ASSESSMENTLEN at 5, the snprintf() generates the format string "%4s%d". The code compiled reads:
Prog 1
and stops. The '1' comes from the 5th character of 'Prog1'; the next assessment name is '20', and then the conversion of 'Quiz' into a number fails, causing the input loop to stop (because only one of two expected items was converted).
Despite the nuisance value, if you want to make your scanf() strings adjust to the size of the data variables it is reading into, you have to do something akin to what I did here - format the string using the correct size values.
i guess, you need to put a
scanf("%s%d", assLabel[i], &assPercent[i]);
space between %s and %d here.
And it is not saving as one. You need to put newline or atlease a space after %s on print to see difference.
add:
when i tried
#include <stdio.h>
int main (int argc, const char * argv[])
{
char a[1][2];
for(int i =0;i<3;i++)
scanf("%s",a[i]);
for(int i =0;i<3;i++)
printf("%s",a[i]);
return 0;
}
with inputs
123456
qwerty
sdfgh
output is:
12qwsdfghqwsdfghsdfgh
that proves that, the size of string array need to be bigger then decleared there.