I'm having issues displaying the serial monitor on an lcd. I am not getting any error and the LCD is lit up so I don't think I wired it wrong. I am able to open up the serial monitor/plotter and see in information changing so my other component is also working so the problem must be in the code...
#include <LiquidCrystal.h>
/**
* LIDARLite I2C Example
* Author: Garmin
* Modified by: Shawn Hymel (SparkFun Electronics)
* Date: June 29, 2017
*
* Read distance from LIDAR-Lite v3 over I2C
*
* See the Operation Manual for wiring diagrams and more information:
* http://static.garmin.com/pumac/LIDAR_Lite_v3_Operation_Manual_and_Technical_Specifications.pdf
*/
#include <Wire.h>
#include <LIDARLite.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
// Globals
LIDARLite lidarLite;
int cal_cnt = 0;
void setup()
{
Serial.begin(9600); // Initialize serial connection to display distance readings
lidarLite.begin(0, true); // Set configuration to default and I2C to 400 kHz
lidarLite.configure(0); // Change this number to try out alternate configurations
lcd.begin(16, 2);
// initialize the serial communications:
}
void loop()
{
int dist;
// At the beginning of every 100 readings,
// take a measurement with receiver bias correction
if ( cal_cnt == 0 ) {
dist = lidarLite.distance(); // With bias correction
} else {
dist = lidarLite.distance(false); // Without bias correction
}
// Increment reading counter
cal_cnt++;
cal_cnt = cal_cnt % 100;
// Display distance
Serial.print(dist);
Serial.println(" cm");
delay(10);
// when characters arrive over the serial port...
if (Serial.available()) {
// wait a bit for the entire message to arrive
delay(100);
// clear the screen
lcd.clear();
// read all the available characters
while (Serial.available() > 0) {
// display each character to the LCD
lcd.write(Serial.read());
}
}
}
The LCD should be displaying the changing measurements
The LCD is lit up and I can adjust the back light but I can't get anything to show up.
Just because the LCD is "lit" doesn't mean it's wired correctly. In fact, the backlighting circuit is usually totally separate from the data and control signals circuits. I would start by checking the assumption that it's wired correctly with a simple command to print a known value to the LCD:
lcd.clear();
lcd.println("TEST");
If this works, then you know the LCD is working and can look elsewhere for the problem.
If this doesn't work, I'd question your assumption that it's hooked up correctly, but if you still get nothing but "blue blocks" then it might be something as simple as your contrast is not correct. It can be tricky getting the contrast and brightness to a good combination for readability. See if your display has a small potentiometer (usually adjustable with a very small Philips-head driver) on the back and carefully adjust the contrast.
Brightness is often changeable through software commands but most LCDs default to high brightness when first booted up.
If changing contrast doesn't work, you may have a real wiring problem and then it really is off-topic for this forum. In that case you should sketch a schematic and post on Electrical Engineering stack.
Related
Hey i got a bit problem with my Arduino and sensor
Here is what i tried ;
#define USE_ARDUINO_INTERRUPTS true // Set-up low-level interrupts for most acurate BPM math.
#include <PulseSensorPlayground.h> // Includes the PulseSensorPlayground Library.
#include <SoftwareSerial.h>
SoftwareSerial blue(0,1);
const int PulseWire = 0; // PulseSensor PURPLE WIRE connected to ANALOG PIN 0
const int LED13 = 13; // The on-board Arduino LED, close to PIN 13.
int Threshold = 550;
PulseSensorPlayground pulseSensor;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
blue.begin(9600);
pulseSensor.analogInput(PulseWire);
pulseSensor.blinkOnPulse(LED13); //auto-magically blink Arduino's LED with heartbeat.
pulseSensor.setThreshold(Threshold);
pulseSensor.begin();
}
void loop() {
// put your main code here, to run repeatedly:
int myBPM = pulseSensor.getBeatsPerMinute();
if(myBPM>200){
myBPM-100;
}
if (pulseSensor.sawStartOfBeat()) {
Serial.println(myBPM);
blue.println(myBPM);
}
delay(10);
}
this code I got from the example library and modified it.
so i want to send data to my android using Bluetooth but this sensor kinda ticked me off because whenever i use it with my HC-06 Bluetooth module it suddenly got a hearth beat without i even touching it and it just sends so much data ignoring the delay I set.
I just need to slowly sending data just like a second but the data didn't show up
so anyone can help?
I read your code and I noticed this piece of code
if(myBPM > 200){ myBPM - 100; }
that is poorly written if (I understand correctly) you want to check the size of myBPM and if it is larger than 200 then it should be subtracted 100.
it should be:
myBPM = myBPM - 100; not myBPM - 100;
I hope my answer will help you. Have a nice day!
I am using a Remote Control from FlySky. For my robotics project, I want to read PWM from the receiver on an Arduino. I came across 2 options:
pulseIn() arduino function
ISR(PCINTx_vect) (interrupt)
I cant use the first option of pulseIn() because I want my robot to continue with the operation if receiver signal are not coming (Tx not available etc.) So I used ISR.
Most reliable source : Mr. Brookings channel on YouTube.
Here is what I did (Only the required part for 1 axis):
// [R] where R is defined as 0 => [R] == [0]
volatile long CH[4]; //4 pwms to read so array of 4
float IN[3]={0,0,0}; // throttle is directly written
unsigned long timer[4],curr_time;
byte last[4];
void setup(){
PCICR |= (1 << PCIE0);
PCMSK0 |= (1 << PCINT0);
PCMSK0 |= (1 << PCINT1);
PCMSK0 |= (1 << PCINT2);
PCMSK0 |= (1 << PCINT3);
/* There is some more code here */
Serial.begin(115200);
}
void loop(){
/* There is some more code here */
IN[R] = ((CH[ROLL] - (1500 + R_TRIM))/11.0); // eg.: (1200 - (1500 + 8))/11.0 = -28 (interpreted as setpoint of -28° by the robot)
Serial.println(IN[R]);
}
ISR(PCINT0_vect){
curr_time = micros();
//channel 1 roll
if(PINB & B00000001){
if(last[ROLL] == 0){
last[ROLL] = 1;
timer[ROLL] = curr_time;
}
}
else if(last[ROLL] == 1){
last[ROLL] = 0;
CH[ROLL] = ((curr_time - timer[ROLL]));
}
}
I can read the PWM actually, but the robot keeps showing random twitches in its control at a given set point. I managed to trace the reason and found out that the PWM is insanely ridden by noise. Its not stable like it should be - steady. I have a MATLAB plot I used for analysis:
Signal (IN[R]):
Close up (when Tx stick was in the middle w/o movement) :
There are such spikes coming which is adding up to the control signal eventually making my robot to twitch. I tried some filtering techniques like 'moving average' and '1st and 2nd order exponential filters'. Also checked if it was due to power supplied to it - tried putting a capacitor or an iron core to the power lines but in vain. I can figure out how to remove them as their some constrains :
platform is Arduino Uno (slower in heavy computation)
Control loop shall not go below 100Hz (Currently its at 108Hz exponential filters on 4 axes took it to
~85Hz)
I would appreciate some guidance!
There's no way of telling from this if the input is noisy, or if your code is reading the PWM wrong, of if something else is going on, like external noise on the line, the Arduino's clock jitter, or other interrupts taking time. Also note that micros() on an Arduino Uno only has a resolution of 4µs, not 1µs.
You should check the input for jitter and noise, and try fast code that isn't influenced by other interrupts.
A fairly simple and fast way of getting the PWM pulse width is something like this, preferably without using anything else that uses interrupts:
volatile int pwmPulseWidth = 0;
volatile unsigned long int previousTime = 0;
void setup() {
attachInterrupt(0, rising, RISING);
}
void loop() {
// pwmPulseWidth is available here.
}
void rising() {
attachInterrupt(0, falling, FALLING);
previousTime = micros();
}
void falling() {
attachInterrupt(0, rising, RISING);
pwmPulseWidth = micros() - previousTime;
}
Untested, but it should give you an idea. This will return the width of the PWM pulse.
There are other ways of doing this, of course, like using a timer in capture mode.
Knowing the PWM frequency and the width of the PWM pulse is enough to reconstruct the PWM signal, should you want to.
I made a nice code which generates fast PWM with 50% duty cycle and I can change the frequency with a potentiometer. It outputs straight and inverted channels with some dead time. I am using Arduino Micro aka ATmega32U4. The code is actually "Atmel" code. Code is working fine until I power Arduino Micro off and then on again.
I have programmed the code and registers so that the frequency is changeable from 10kHz to 100kHz. But after power on/off the frequency changes from 5kHz to 50kHz. After this has happened I have to program the board again using Arduino IDE, to make it work correctly. Again after power on/off it has changed. I am quite sure that one of the registers is overwritten by the "Arduino hardware abstraction layer" or however we should name it. I have not yet read out all the registers so I do not know which one is overwritten. I guess it's the prescaler.
How do I prevent this from happening? Should I write the register contents somewhere else? Or should I write it few times to be sure?
Why or how this is happening anyway?
Here's the code:
#define OSC1 5
#define OSC2 13
uint8_t read_reg1;
uint8_t read_reg2;
int pot, freq;
void setup() {
pinMode(OSC1, OUTPUT);
pinMode(OSC2, OUTPUT);
Serial.begin(9600);
cli(); // disable global interrupts
TCCR4A=0; // clear register
TCCR4B=0x06; // configure prescaler to 64 (CK = CLK / 64 = 1.5 MHz)
TCCR4C=0;
TCCR4D=0; // select Fast PWM operation (0 << WGM41)|(0 << WGM40)
PLLFRQ=(PLLFRQ&0xCF)|0x30; // select clock source and frequency
OCR4C=150; // select PWM frequency
OCR4A=150/2; // set duty cycle
DT4 = 0x55; // set dead times. DT = (1 / 48Mhz) * 0...15
// enable interrupt on timer4 overflow
TIMSK4|=(1 << TOIE4);
// This register write has to be after others. Otherwise the PWM generation will not work. I do not know why.
TCCR4A=0x42; // COM4A1..0 = 01, OC4A and !OC4A connected. PWM4A = 1 (activate channel A PWM output)
sei(); // enable global interrupts
}
void loop() {
//cli();
pot = analogRead(A0);
freq = map(pot, 0, 1023, 14, 166);
//sei();
/*
Serial.print("Pot value: ");
Serial.print(pot);
Serial.print("\tFreq value: ");
Serial.println(1500000/freq);
*/
}
ISR(TIMER4_OVF_vect){
OCR4C = freq;
OCR4A = freq / 2;
}
I am not sure exactly why you got different behavior right after programming, but the bootloader that the Arduino Micro uses (Caterina) does not perform a full reset after it runs, so changes that the bootloader made to the AVR's registers are often visible to the user's sketch.
I was able to fix the problem by removing the line that modifies PLLFRQ. Here is a simplified version of your code that always produces 3.31 kHz PWM:
void setup()
{
pinMode(5, OUTPUT);
pinMode(13, OUTPUT);
TCCR4A = 0;
TCCR4B = 0x06; // configure prescaler to 64 (CK = CLK / 64 = 1.5 MHz)
TCCR4C = 0;
TCCR4D = 0; // select Fast PWM operation (0 << WGM41)|(0 << WGM40)
OCR4C = 150; // select PWM frequency
OCR4A = 150 / 2; // set duty cycle
DT4 = 0x55; // set dead times. DT = (1 / 48Mhz) * 0...15
// This register write has to be after others.
// Otherwise the PWM generation will not work. I do not know why.
// COM4A1..0 = 01, OC4A and !OC4A connected.
// PWM4A = 1 (activate channel A PWM output)
TCCR4A = 0x42;
}
void loop()
{
}
It's not a great idea to mess with the PLL postscaler since it will probably affect every other Arduino library that uses timers, including the USB stack.
I am learning Arduino and I was making one program which will print "Hello" to the lcd display connected to arduino.
I dont know what is wrong but the LCD is not showing desired output, rather shows special characters and when I increase/decrease the contrast of lcd using the Potentiometer, the characters changes everytime.
my code is:
// include the library code:
#include <LiquidCrystal.h>
// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello");
}
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 the number of seconds since reset:
lcd.print(millis() / 1000);
}
Please help.
Check what kind of lcd you are using.
Some lcd's come with the pin numbering reversed. IE the location of the 16 pins is on the top left corner, but instead of starting with pin number 1, the lcd starts with pin number 16.
Since the format of the LCD pins is the same both way (GND, VCC, input * 14, vcc, Gnd) it does not cause shorting problems, But the control signals are sent to the data pins, and the data signals are sent to the control pins.
I got this hint from the fact that changing the brightness changes the characters. If I am right, changing the contrast via the potentiometer will do you no good with respect to the actual contrast.
I have this RFID reader "Rosslare AY-X12", and it's working with Wiegand 26bit. I have an arduino mini Pro and connected together it's working fine but it only reads the card one time and then I have nothing.
When I put on the card arduino reads that card but only one time during the card is near by the reader and it again reads that card when I put off the card and then I put on. But I want to read that card continuously, I mean when the card is near by the Reader still reading the card, every 1ms reads that card.
Do you have any idea how to do that ? Is there any RFID arduino library which can do that? I had got the Mifare and its can do that. But this 125Khz reader which can communicate over Wiegand can't do that or I don't know how to do that.
I'm using this library : https://github.com/monkeyboard/Wiegand-Protocol-Library-for-Arduino
My previous answer was deleted. I am going to make another attempt to answer the questions.
Do you have any idea how to do that ?
This cannot be done by Arduino because Arduino in your case is just reading the D0 and D1 pulses from your RFID reader. Since your RFID reader Rosslare AY-X12 does not send out continuous output of wiegand protocol, there is no way Arduino can read more than what was not sent to it.
The common RFID readers will not send continuous data of the same card because in the common use case (entry/exit/attendance), normally one tap is to check-in and another tap is to check-out. If the RFID reader sends continuous data of the same card, the main system receiving the multiple wiegand data will be confused and will not be able to determine if the user actually wish to check-in or check-out.
Is there any RFID arduino library which can do that?
No. There is no such RFID Arduino library. If the RFID reader is not sending out continuous data, there is no way the receiver (Arduino) can receive them.
Is there a way to achieve this?
Yes, there are some readers that has the option to turn on the continuous output of data, for example 714-52 Mifare® ID Reader with selectable outputs. In its specification :
Continuous output with tag in field or single transmission
With this reader configured to continuous output, you can then use Arduino and the monkeyboard wiegand library to read the data.
I wrote my own wiegand code. Its not that difficult. I attached interrupts to the data pins and when they change I log the zero or one. You then build up the binary string and once timed out because no bits coming in. Then you convert the binary to decimal.
#include <LiquidCrystal.h>
int data0 = 2; //set wiegand data 0 pin
int data1 = 3; //set wiegand data 1 pin
unsigned long bit_holder; //unsigned long (positive 32 bit number)
unsigned long oldbit = 0;
volatile int bit_count = 0;
LiquidCrystal lcd(8, 9, 10, 11, 12, 13);
unsigned long badge;
unsigned int timeout;
unsigned int t = 800;
void setup() {
Serial.begin(9600);
lcd.begin(16, 2);
lcd.print("Present Badge");
delay(2);
Serial.println("Present Badge");
pinMode(data0, INPUT);
digitalWrite(data0, HIGH);
pinMode(data1, INPUT);
digitalWrite(data1, HIGH);
attachInterrupt(0, zero, FALLING); //attach interrupts and assign functions
attachInterrupt(1, one, FALLING);
}
void zero(){
bit_count ++;
bit_holder = (bit_holder << 1) + 0; //shift left one and add a 0
timeout = t;
}
void one(){
bit_count ++;
bit_holder = (bit_holder << 1) + 1; //shift left one and add a 1
timeout = t;
}
void loop() {
timeout --;
if (timeout == 0 && bit_count > 0){
lcd.clear();
lcd.print("Dec:");
lcd.print(bit_holder);
lcd.setCursor(0,1);
lcd.print("Hex:");
lcd.print(String(bit_holder,HEX));
Serial.print("bit count= ");
Serial.println(bit_count);
Serial.print("bits= ");
Serial.println(bit_holder,BIN);
oldbit = bit_holder; //store previous this value as previous
bit_count = 0; //reset bit count
bit_holder = 0; //reset badge number
}
}
You may need to find a reader that offer a continuously reading, as I know almost of Wiegand Reader in the market can't perform a continuously reading because they have a "onboard" control that controls this...
Maybe you can try with Arduino Serial RFID Reader...
try a this timer libary Timer1 and mayby try this code it worked for me, my tags and cards now reads continuously.
Greetings from Denmark
Gregor
#include <Timer1.h>
//******************************************************************
// ATmega168, ATmega328:
// - Using Timer 1 disables PWM (analogWrite) on pins 9 and 10
// ATmega2560:
// - Using Timer 1 disables PWM (analogWrite) on pins 11 and 12
// - Using Timer 3 disables PWM (analogWrite) on pins 2, 3 and 5
// - Using Timer 4 disables PWM (analogWrite) on pins 6, 7 and 8
// - Using Timer 5 disables PWM (analogWrite) on pins 44, 45 and 46
//******************************************************************
unsigned int lastTime;
#include <SoftwareSerial.h>
SoftwareSerial RFID = SoftwareSerial(2,4);
char character;
String our_id;
void setup()
{
// Disable Arduino's default millisecond counter (from now on, millis(), micros(),
// delay() and delayMicroseconds() will not work)
disableMillis();
// Prepare Timer1 to count
// On 16 MHz Arduino boards, this function has a resolution of 4us
// On 8 MHz Arduino boards, this function has a resolution of 8us
startCountingTimer1();
lastTime = readTimer1();
Serial.begin(9600);
RFID.begin(9600);
}
void loop()
{
unsigned int now = readTimer1();
while (RFID.available()>0)
{
character = RFID.read();
our_id += character;
lastTime = now;
}
if (our_id.length() > 10) {
our_id = our_id.substring(1,13);
Serial.println(our_id);
our_id = "";
}
delay(1000);
}