I am trying to create a basic arduino uno stopwatch displayed on a liquid crystal display. In theory , this is a very easy project, yet I am running into issues with my display. I calculate my minutes and seconds, and then attempt to print them to the display with a colon in between. Coming from java, I presumed a plus was just used. However, this results in a bunch of random, unidentifiable characters flashing on the screen. I tested to see if both seconds and minutes work separate, which they do, so I think it is in the syntax of lcd.print(). I was not able to find this addressed anywhere else. Help would be appreciated.
Code:
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int seconds;
int minutes;
int timedif;
int starttime = -1;
void setup()
{
lcd.begin(16, 2); //Initialize the 16x2 LCD
lcd.clear(); //Clear any old data displayed on the LCD
}
void loop()
{
lcd.setCursor(0,0);
lcd.print("Stopwatch");
lcd.setCursor(0,1);
if (starttime == -1) { //if running first time, time dif is initiated
starttime = millis();
}
timedif = (millis() - starttime)/1000; //will get difference in terms of seconds
minutes = floor(timedif/60); // divides by sixty, drops decimal
seconds = timedif%60; //gets remainder of divided by 60
lcd.print(minutes + ";" + seconds);
}
What you are printing is a JAVA syntax , and Arduino is using C syntax.
See this on how you need to use this API.
You need to build the string (for example as char array) and passed it to the print method
Related
does any one here experienced with various dht11 library for arduino?, I want to read the temperature value every 30 second, I am using the standard library but sometimes throw me NaN. In avarege I got 2 NaN values out of 10 readings (20%).
I got many errors about many dht11 libraries, but one day finally I found a good library and good example code.
Firstly you have to download the library from this link and add this to arduino's library folder.
Secondly, you should do this pin connections
Lastly, here it is example code. It should work.
#include <dht11.h>
int DHT11_pin=2;
dht11 DHT11_sensor;
void setup()
{
Serial.begin(9600);
Serial.println("GOOD LUCK");
Serial.println("*********************");
}
void loop()
{
int chk = DHT11_sensor.read(DHT11_pin);
Serial.print("Humidity (%): ");
Serial.println((float)DHT11_sensor.humidity, 2);
Serial.print("Temp (Celcius): ");
Serial.println((float)DHT11_sensor.temperature);
Serial.print("Temp (Kelvin): ");
Serial.println(DHT11_sensor.kelvin(), 2);
Serial.print("Temp (Fahrenheit): ");
Serial.println(DHT11_sensor.fahrenheit(), 2);
Serial.print("Dew Point: ");
Serial.println(DHT11_sensor.dewPoint(), 2);
Serial.println("------------------");
delay(500);
}
code dose not perfect work
int pushButton = 2;
int gearstatus = 0 ;
int buttonState;
void setup() {
Serial.begin(9600);
pinMode(pushButton, INPUT);
}
void gearfunction(){
buttonState = digitalRead(pushButton);
while(gearstatus <= 5){
Serial.println( gearstatus);
if(buttonState == HIGH){
gearstatus++;}
}
}
void loop() {
gearfunction();
}
in this code i am trying to if statement in while loop,
but code doesn't work . can some one give me how to did this ? i want to increase gearstatus up to 5 but value not increase .
It doesn't work because marking pushButton as INPUT wont make it equal to HIGH
You need to put inside setup function after the input instruction:
digitalWrite(pushButton,HIGH)
A Button-Pin has to be initialized on Setup, like in the preceding answer or with:
pinMode(2, INPUT_PULLUP); //Pin-D2. This command activates it's internal
//resistor, so the resulting signal is clear HIGH and not floating like a duck...
Hint: on StartUp all pins of a uC are floating-inputs, so if pulled-UP
they may be grounded with a button or anything else like a sensor, NTC-Resistor, etc.), resulting in a clear "1" or "0" - or a defined Analog-Signal, which later may be scanned like:
boolean buttonState = digitalRead(2); //Pin D2
//or
int value = analogRead(A0); //Pin A0
Can you please explain a little what you are trying to do, It would be better if you attach a small image of the circuit. I can suggest you the code and answer using circuits.io if you give the required info.
I've searched the net, I've searched here. I've found code that I could compile and it works fine, but for some reason my code won't produce any sound. I'm porting an old game to the PC (Windows,) and I'm trying to make it as authentic as possible, so I'm wanting to use generated wave forms. I've pretty much copied and pasted the working code (only adding in multiple voices,) and it still won't work (even thought the exact same code for a single voice works fine.) I know I'm missing something obvious, but I just cannot figure out what. Any help would be appreciated thank you.
First some notes... I was looking for something that would allow me to use the original methodology. The original system used paired bytes for music (sound effects - only 2 - were handled in code.) A time byte that counted down every time the routine was called, and a note byte that was played until time reached zero. this was done by patching into the interrupt vector, windows doesn't allow that, so I set up a timer that routing that accomplished the same thing. The timer kicks in, updates the display, and then runs the music sequence. I set this up with a defined time so that I only have one place to adjust the timing at (to get it as close as possible to the original sequence. The music is a generated wave form (and I've double checked the math, and even examined the generated data in debug mode,) and it looks good. The sequence looks good, but doesn't actually produce sound. I tried SDL2 first, and it's method of only playing 1 sound doesn't work for me, also, unless I make the sample duration extremely short (and the sound produced this way is awful,) I can't match the timing (it plays the entire sample through it's own interrupt without letting me make adjustments.) Also, blending the 3 voices together (when they all run with different timings,) is a mess. Most of the other engines I examined work in much the same way, they want to use their own callback interrupt and won't allow me to tweak it appropriately. This is why I started working with OpenAL. It allows multiple voices (sources,) and allows me to set the timings myself. On advice from several forums, I set it up so that the sample lengths are all multiples of full cycles.
Anyway, here's the code.
int main(int argc, char* argv[])
{
FreeConsole(); //Get rid of the DOS console, don't need it
if (InitLog() < 0) return -1; //Start logging
UINT_PTR tim = NULL;
SDL_Event event;
InitVideo(false); //Set to window for now, will put options in later
curmusic = 5;
InitAudio();
SetTimer(NULL,tim,_FREQ_,TimerProc);
SDL_PollEvent(&event);
while (event.type != SDL_KEYDOWN) SDL_PollEvent(&event);
SDL_Quit();
return 0;
}
void CALLBACK TimerProc(HWND hWind, UINT Msg, UINT_PTR idEvent, DWORD dwTime)
{
RenderOutput();
PlayMusic();
//UpdateTimer();
//RotateGate();
return;
}
void InitAudio(void)
{
ALCdevice *dev;
ALCcontext *cxt;
Log("Initializing OpenAL Audio\r\n");
dev = alcOpenDevice(NULL);
if (!dev) {
Log("Failed to open an audio device\r\n");
exit(-1);
}
cxt = alcCreateContext(dev, NULL);
alcMakeContextCurrent(cxt);
if(!cxt) {
Log("Failed to create audio context\r\n");
exit(-1);
}
alGenBuffers(4,Buffer);
if (alGetError() != AL_NO_ERROR) {
Log("Error during buffer creation\r\n");
exit(-1);
}
alGenSources(4, Source);
if (alGetError() != AL_NO_ERROR) {
Log("Error during source creation\r\n");
exit(-1);
}
return;
}
void PlayMusic()
{
static int oldsong, ofset, mtime[4];
double freq;
ALuint srate = 44100;
ALuint voice, i, note, len, hold;
short buf[4][_BUFFSIZE_];
bool test[4] = {false, false, false, false};
if (curmusic != oldsong) {
oldsong = (int)curmusic;
if (curmusic > 0)
ofset = moffset[(curmusic - 1)];
for (voice = 1; voice < 4; voice++)
alSourceStop(Source[voice]);
mtime[voice] = 0;
return;
}
if (curmusic == 0) return;
//Only 3 voices for music, but have
for (voice = 0; voice < 3; voice ++) { // 4 set asside for eventual sound effects
if (mtime[voice] == 0) { //is note finished
alSourceStop(Source[voice]); //It is, so stop the channel (source)
mtime[voice] = music[ofset++]; //Get the next duration
if (mtime[voice] == 0) {oldsong = 0; return;} //zero marks end, so restart
note = music[ofset++]; //Get the next note
if (note > 127) { //Old HW data was designed for could only
if (note == 255) note = 127; //use values 128 - 255 (255 = 127)
freq = (15980 / (voice + (int)(voice / 3))) / (256 - note); //freq of note
len = (ALuint)(srate / freq); //A single cycle of that freq.
hold = len;
while (len < (srate / (1000 / _FREQ_))) len += hold; //Multiply till 1 interrup cycle
while (len > _BUFFSIZE_) len -= hold; //Don't overload buffer
if (len == 0) len = _BUFFSIZE_; //Just to be safe
for (i = 0; i < len; i++) //calculate sine wave and put in buffer
buf[voice][i] = (short)((32760 * sin((2 * M_PI * i * freq) / srate)));
alBufferData(Buffer[voice], AL_FORMAT_MONO16, buf[voice], len, srate);
alSourcei(openAL.Source[i], AL_LOOPING, AL_TRUE);
alSourcei(Source[i], AL_BUFFER, Buffer[i]);
alSourcePlay(Source[voice]);
}
} else --mtime[voice];
}
}
Well, it turns out there were 3 problems with my code. First, you have to link the built wave buffer to the AL generated buffer "before" you link the buffer to the source:
alBufferData(buffer,AL_FORMAT_MONO16,&wave_sample,sample_lenght * sizeof(short),frequency);
alSourcei(source,AL_BUFFER,buffer);
Also in the above example, I multiplied the sample_length by how many bytes are in each sample (in this case "sizeof(short)".
The final problem was that you need to un-link a buffer from the source before you change the buffer data
alSourcei(source,AL_BUFFER,NULL);
The music would play, but not correctly until I added that line to the note change code.
I'm looking for a way to obtain a guaranteed-monotonic clock which excludes time spent during suspend, just like POSIX CLOCK_MONOTONIC.
Solutions requiring Windows 7 (or later) are acceptable.
Here's an example of something that doesn't work:
LONGLONG suspendTime, uiTime1, uiTime2;
do {
QueryUnbiasedInterruptTime((ULONGLONG*)&uiTime1);
suspendTime = GetTickCount64()*10000 - uiTime1;
QueryUnbiasedInterruptTime((ULONGLONG*)&uiTime2);
} while (uiTime1 != uiTime2);
static LARGE_INTEGER firstSuspend = suspendTime;
static LARGE_INTERER lastSuspend = suspendTime;
assert(suspendTime > lastSuspend);
lastSuspend = suspendTime;
LARGE_INTEGER now;
QueryPerformanceCounter(&now);
static LONGLONG firstQpc = now.QuadPart;
return (now.QuadPart - firstQpc)*qpcFreqNumer/qpcFreqDenom -
(suspendTime - firstSuspend);
The problem with this (my first attempt) is that GetTickCount only ticks every 15ms, wheras QueryUnbiasedInterruptTime seems to tick a little more often, so every now and then my method observes the suspend time go back by a little.
I've also tried using CallNtPowerInformation, but it's not clear how to use those values either to get a nice, race-free measure of suspend time.
The suspend bias time is available in kernel mode (_KUSER_SHARED_DATA.QpcBias in ntddk.h). A read-only copy is available in user mode.
#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>
LONGLONG suspendTime, uiTime1, uiTime2;
QueryUnbiasedInterruptTime((ULONGLONG*)&uiTime1);
uiTime1 -= USER_SHARED_DATA->QpcBias; // subtract off the suspend bias
The full procedure for calculating monotonic time, which does not tick during suspend, is as follows:
typedef struct _KSYSTEM_TIME {
ULONG LowPart;
LONG High1Time;
LONG High2Time;
} KSYSTEM_TIME;
#define KUSER_SHARED_DATA 0x7ffe0000
#define InterruptTime ((KSYSTEM_TIME volatile*)(KUSER_SHARED_DATA + 0x08))
#define InterruptTimeBias ((ULONGLONG volatile*)(KUSER_SHARED_DATA + 0x3b0))
static LONGLONG readInterruptTime() {
// Reading the InterruptTime from KUSER_SHARED_DATA is much better than
// using GetTickCount() because it doesn't wrap, and is even a little quicker.
// This works on all Windows NT versions (NT4 and up).
LONG timeHigh;
ULONG timeLow;
do {
timeHigh = InterruptTime->High1Time;
timeLow = InterruptTime->LowPart;
} while (timeHigh != InterruptTime->High2Time);
LONGLONG now = ((LONGLONG)timeHigh << 32) + timeLow;
static LONGLONG d = now;
return now - d;
}
static LONGLONG scaleQpc(LONGLONG qpc) {
// We do the actual scaling in fixed-point rather than floating, to make sure
// that we don't violate monotonicity due to rounding errors. There's no
// need to cache QueryPerformanceFrequency().
LARGE_INTEGER frequency;
QueryPerformanceFrequency(&frequency);
double fraction = 10000000/double(frequency.QuadPart);
LONGLONG denom = 1024;
LONGLONG numer = std::max(1LL, (LONGLONG)(fraction*denom + 0.5));
return qpc * numer / denom;
}
static ULONGLONG readUnbiasedQpc() {
// We remove the suspend bias added to QueryPerformanceCounter results by
// subtracting the interrupt time bias, which is not strictly speaking legal,
// but the units are correct and I think it's impossible for the resulting
// "unbiased QPC" value to go backwards.
LONGLONG interruptTimeBias, qpc;
do {
interruptTimeBias = *InterruptTimeBias;
LARGE_INTEGER counter;
QueryPerformanceCounter(&counter);
qpc = counter.QuadPart;
} while (interruptTimeBias != *InterruptTimeBias);
static std::pair<LONGLONG,LONGLONG> d(qpc, interruptTimeBias);
return scaleQpc(qpc - d.first) - (interruptTimeBias - d.second);
}
/// getMonotonicTime() returns the time elapsed since the application's first
/// call to getMonotonicTime(), in 100ns units. The values returned are
/// guaranteed to be monotonic. The time ticks in 15ms resolution and advances
/// during suspend on XP and Vista, but we manage to avoid this on Windows 7
/// and 8, which also use a high-precision timer. The time does not wrap after
/// 49 days.
uint64_t getMonotonicTime()
{
OSVERSIONINFOEX ver = { sizeof(OSVERSIONINFOEX), };
GetVersionEx(&ver);
bool win7OrLater = (ver.dwMajorVersion > 6 ||
(ver.dwMajorVersion == 6 && ver.dwMinorVersion >= 1));
// On Windows XP and earlier, QueryPerformanceCounter is not monotonic so we
// steer well clear of it; on Vista, it's just a bit slow.
return win7OrLater ? readUnbiasedQpc() : readInterruptTime();
}
I'm a newby to robotics and electronics in general, so please don't assume I tried anything you might think is obvious.
I'm trying to create a cart which will basically run around by itself (simple AI routines to avoid obstacles, go from pt. A to pt. B around corners, follow lines, etc.). I'm putting together an Adafruit Arduino Uno R3 with the Adafruit Motor Shield v2 and an MPU-6050. I'm using the "breadboard" on the Motor Shield for the circuitry, soldering everything there.
I can get all the pieces working independently with their own scripts: the Motor Shield drives the 4 motors as expected using the Adafruit library; I'm using the "JRowberg" library for the MPU-6050, and started with the example MPU6050_DMP6.ino, which works fine as long as the cart motors are turned off. My only changes in the example script below are motor startup and some simple motor commands.
As long as I leave the switch which powers the motors off, everything seems fine: it outputs to the Serial window continuously with Euler data which, I assume, is correct. However, a few seconds after I turn on the power to the motors (and the wheels start turning), it just hangs/freezes: the output to the Serial window stops (sometimes in mid-line), and the wheels keep turning at the speed of their last change. Sometimes I see "FIFO overflow" errors, but not always. Sometimes I see "nan" for some of the floating point values before it hangs, but not always.
Some things I've tried, all of which changed noting:
* I've swapped out the MPU-6050 board for another from the same manufacturer.
* I've tried moving the MPU-6050 away from the motors using a ribbon cable.
* I've changed the I2C clock using JRowber's advice (a change in a .h file and changing the value of the TWBR variable), but I don't think I've tried all possible values.
* I've changed the speed of the MotorShield in the AFMS.begin() command, although, again, there are probably other values I haven't tried, and I'm not sure how in-sync this and the TWBR value need to be.
And some other things, all to no avail.
Below is an example script which fails for me:
#include "I2Cdev.h"
#include "MPU6050_6Axis_MotionApps20.h"
// is used in I2Cdev.h
#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
#include "Wire.h"
#endif
#include "Adafruit_MotorShield.h"
#include "utility/Adafruit_PWMServoDriver.h"
#define DEBUG 1
MPU6050 mpu;
#define OUTPUT_READABLE_EULER
#define LED_PIN 13
bool blinkState = false;
bool dmpReady = false; // set true if DMP init was successful
uint8_t mpuIntStatus; // holds actual interrupt status byte from MPU
uint8_t devStatus; // return status after each device operation (0 = success, !0 = error)
uint16_t packetSize; // expected DMP packet size (default is 42 bytes)
uint16_t fifoCount; // count of all bytes currently in FIFO
uint8_t fifoBuffer[64]; // FIFO storage buffer
Quaternion q; // [w, x, y, z] quaternion container
VectorInt16 aa; // [x, y, z] accel sensor measurements
VectorInt16 aaReal; // [x, y, z] gravity-free accel sensor measurements
VectorInt16 aaWorld; // [x, y, z] world-frame accel sensor measurements
VectorFloat gravity; // [x, y, z] gravity vector
float euler[3]; // [psi, theta, phi] Euler angle container
float ypr[3]; // [yaw, pitch, roll] yaw/pitch/roll container and gravity vector
uint8_t teapotPacket[14] = { '$', 0x02, 0,0, 0,0, 0,0, 0,0, 0x00, 0x00, '\r', '\n' };
Adafruit_MotorShield AFMS = Adafruit_MotorShield();
#define NUM_MOTORS 4
#define MOTOR_FL 0
#define MOTOR_FR 1
#define MOTOR_RR 2
#define MOTOR_RL 3
Adafruit_DCMotor *myMotors[NUM_MOTORS] = {
AFMS.getMotor(1),
AFMS.getMotor(2),
AFMS.getMotor(3),
AFMS.getMotor(4),
};
#define CHANGE_SPEED_TIME 500
long changeSpeedMillis = 0;
int curSpeed = 30;
volatile bool mpuInterrupt = false; // indicates whether MPU interrupt pin has gone high
void dmpDataReady() {
mpuInterrupt = true;
}
void setup() {
#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
Wire.begin();
TWBR = 24; // 400kHz I2C clock (200kHz if CPU is 8MHz)
#elif I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_FASTWIRE
Fastwire::setup(400, true);
#endif
Serial.begin(115200);
while (!Serial); // wait for Leonardo enumeration, others continue immediately
// start the motor shield.
AFMS.begin(); // create with the default frequency 1.6KHz
// AFMS.begin(4000); // OR with a different frequency, say 4KHz
// kill all the motors.
myMotors[MOTOR_FL]->run(BRAKE);
myMotors[MOTOR_FL]->setSpeed(0);
myMotors[MOTOR_FR]->run(BRAKE);
myMotors[MOTOR_FR]->setSpeed(0);
myMotors[MOTOR_RR]->run(BRAKE);
myMotors[MOTOR_RR]->setSpeed(0);
myMotors[MOTOR_RL]->run(BRAKE);
myMotors[MOTOR_RL]->setSpeed(0);
Serial.println("Motor Shield ready!");
Serial.println(F("Initializing I2C devices..."));
mpu.initialize();
// verify connection
Serial.println(F("Testing device connections..."));
Serial.println(mpu.testConnection() ? F("MPU6050 connection successful") : F("MPU6050 connection failed"));
// wait for ready
Serial.println(F("\nSend any character to begin DMP programming and demo: "));
while (Serial.available() && Serial.read()); // empty buffer
while (!Serial.available()); // wait for data
while (Serial.available() && Serial.read()); // empty buffer again
// load and configure the DMP
Serial.println(F("Initializing DMP..."));
devStatus = mpu.dmpInitialize();
// supply your own gyro offsets here, scaled for min sensitivity
mpu.setXGyroOffset(220);
mpu.setYGyroOffset(76);
mpu.setZGyroOffset(-85);
mpu.setZAccelOffset(1788); // 1688 factory default for my test chip
// make sure it worked (returns 0 if so)
if (devStatus == 0) {
// turn on the DMP, now that it's ready
Serial.println(F("Enabling DMP..."));
mpu.setDMPEnabled(true);
// enable Arduino interrupt detection
Serial.println(F("Enabling interrupt detection (Arduino external interrupt 0)..."));
attachInterrupt(0, dmpDataReady, RISING);
mpuIntStatus = mpu.getIntStatus();
// set our DMP Ready flag so the main loop() function knows it's okay to use it
Serial.println(F("DMP ready! Waiting for first interrupt..."));
dmpReady = true;
// get expected DMP packet size for later comparison
packetSize = mpu.dmpGetFIFOPacketSize();
} else {
// ERROR!
// 1 = initial memory load failed
// 2 = DMP configuration updates failed
// (if it's going to break, usually the code will be 1)
Serial.print(F("DMP Initialization failed (code "));
Serial.print(devStatus);
Serial.println(F(")"));
}
// configure LED for output
pinMode(LED_PIN, OUTPUT);
}
void loop() {
// if programming failed, don't try to do anything
if (!dmpReady) return;
// wait for MPU interrupt or extra packet(s) available
while (!mpuInterrupt && fifoCount < packetSize) {
// as per Vulpo's post.
delay(10);
if (millis() > changeSpeedMillis) {
curSpeed += 20;
if (curSpeed > 256) {
curSpeed = 30;
}
Serial.print("changing speed to: ");
Serial.println(curSpeed);
myMotors[MOTOR_FL]->run(FORWARD);
myMotors[MOTOR_FL]->setSpeed(curSpeed);
myMotors[MOTOR_FR]->run(FORWARD);
myMotors[MOTOR_FR]->setSpeed(curSpeed);
myMotors[MOTOR_RR]->run(FORWARD);
myMotors[MOTOR_RR]->setSpeed(curSpeed);
myMotors[MOTOR_RL]->run(FORWARD);
myMotors[MOTOR_RL]->setSpeed(curSpeed);
changeSpeedMillis = millis() + CHANGE_SPEED_TIME;
}
}
// reset interrupt flag and get INT_STATUS byte
mpuInterrupt = false;
mpuIntStatus = mpu.getIntStatus();
// get current FIFO count
fifoCount = mpu.getFIFOCount();
// check for overflow (this should never happen unless our code is too inefficient)
if ((mpuIntStatus & 0x10) || fifoCount == 1024) {
// reset so we can continue cleanly
mpu.resetFIFO();
Serial.println(F("FIFO overflow!"));
// otherwise, check for DMP data ready interrupt (this should happen frequently)
} else if (mpuIntStatus & 0x02) {
// wait for correct available data length, should be a VERY short wait
while (fifoCount < packetSize) fifoCount = mpu.getFIFOCount();
// read a packet from FIFO
mpu.getFIFOBytes(fifoBuffer, packetSize);
// track FIFO count here in case there is > 1 packet available
// (this lets us immediately read more without waiting for an interrupt)
fifoCount -= packetSize;
#ifdef OUTPUT_READABLE_EULER
// display Euler angles in degrees
mpu.dmpGetQuaternion(&q, fifoBuffer);
mpu.dmpGetEuler(euler, &q);
Serial.print("euler\t");
Serial.print(euler[0] * 180/M_PI);
Serial.print("\t");
Serial.print(euler[1] * 180/M_PI);
Serial.print("\t");
Serial.println(euler[2] * 180/M_PI);
#endif
// blink LED to indicate activity
blinkState = !blinkState;
digitalWrite(LED_PIN, blinkState);
}
}
Have you considered that your troubles are caused by interference from the currents flowing into your motors?
If your motors are DC brush, then more interference may be radiated from the brushes back into your various wires.
As a first step, perhaps let only one motor work and see if hangups diminish in frequency (although, to be sure, you need a 'scope onto a few wires carrying logic signals.