So my problem is as title says: Arduino UNO analogRead always returns 1023.
But when I burn the same sketch in Arduino Mega 2650 everything works like a charm.
I have tried to change Atmel chips on the UNO, have tried like 3 of them (ATMEGA328P-PU) and nothing changes.
I'm trying to count signals from a hall effect sensor and display the count on a 7 segment display.
Here is the code:
#include "SevSeg.h"
SevSeg sevseg;
volatile int rpmcount;
void setup() {
Serial.begin(9600);
pinMode(2,INPUT_PULLUP);
rpmcount = 0;
sevseg.Begin(1,3,4,5,6,7,8,9,10,11,12,13);
}
int border=15;
void loop() {
int tmp=0;
tmp = analogRead(0);
if(!digitalRead(2))rpmcount=0;
Serial.println(tmp,DEC);
if(tmp<=border && res >border){
rpmcount++;
if(rpmcount>9999)rpmcount=0;
}
res=tmp;
sevseg.NewNum(rpmcount,(byte) 0);
sevseg.PrintOutput();
}
Any help would be much appreciated
This sounds to me as if you had the internal pullup resistor on the ADC pin enabled.
generic checklist:
ACD bit in ACSR is 0 (comparator enable)
MUX bits in ADMUX set properly
correct AREF selected
ADC pin set as input
internal pull up resistors are deselected
Related
Hi I am attempting to read from an rc transmitter using an Arduino Uno board, I have a signal pin connected from the receiver to pin 9 on the Arduino. Here is the code I would really appreciate some help all I am trying to achieve is the read the pmw from the receiver. I am able to plug a servo into the receiver and that works fine along with a motor I am just struggling when I try and use the Arduino with the receiver. When I run my program all I get in the Serial monitor are values such as 9991,9972,10030,10050 that are completely unrelated.
I want to have a pmw value that I can map to 0-255 in order to control a motor
My Circuit:
battery -> ESC(for BEC to regulate five volts back to receiver)-> receiver -> ch3 signal pin -> Arduino uno (pin9)
void setup() {
Serial.begin(9600);
}
void loop() {
int pwm = pulseIn(9, HIGH, 25000);
Serial.println(pwm);
delay (5);
}
You are using pulseIn which returns a time (in ms). The time being how long it waited for a HIGH signal. If you want the actual value, use analogRead. You can still use pulseIn, just don't use the return value
void setup() {
Serial.begin(9600);
}
void loop() {
byte pwm = analogRead(A5) / 4;
Serial.println(pwm);
delay(5);
}
The CDS sensor module connected to the Arduino Nano returns only a value of 1023.
my code hear
int Cds = A0;
//int Led = 13;
int value;
void setup() {`enter code here`
Serial.begin(9600);
pinMode(Cds,INPUT);
//pinMode(Led,OUTPUT);
}
void loop() {
Cds=analogRead(A0);
Serial.println(Cds);
if(Cds<300)
Serial.println("dark");
else
Serial.println("bright");
delay(1000);
}
and nano is connected breadboard
Check analogReference() in the code for your board to configures the reference voltage used for analog input. If you have have correct reference voltage setup you get 1023 max value all the time.
Firstly, the first line in loop() should be changed to:
value = analogRead(Cds)
And from there, just use value for accessing the brightness, because Cds is just your alias for A0
The second possible Error source could be this:
If you just connect the module to GPIO and GND, nothing will happen, and it will always read the maximum value (1023).
You need to use it like a voltage divider, to read values which are relative to a certain voltage
If you connect everything like this, it should work.
I have a set of leds that are setup every other led reversed so when I apply power one way light 1,3,5... light. Change power and 2,4,6... I'm trying to set the brightness using PWM on the digital pins. Here's my code:
unsigned long flashCount = 0;
bool bSwitch = true;
void setup()
{
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);
}
void loop()
{
if((flashCount + 1000) < millis())
{
if(bSwitch)
{
analogWrite(6, 0);
analogWrite(7, 1);
bSwitch = false;
}
else
{
analogWrite(7, 0);
analogWrite(6, 1);
bSwitch = true;
}
flashCount = millis();
}
}
If I change analogWrite to 255 instead of 1, it will switch both sets of leds. If I change analogWrite to 127 or less, only one set will light. If I switch the led wires to the pins, the problem switches to the other set of lights.
The leds are like so:
GPIO pin 6 --------.-LED+.---.-LED+.---.-LED+.---.-LED+.---|
GPIO pin 7 ---.+LED-.---.+LED-.---.+LED-.---.+LED-.--------|
Change the connection of the LEDs to pins that both support PWM.
Not all pins support PWM. The analogWrite documentation specifies which pins depending on which board:
On most Arduino boards (those with the ATmega168 or ATmega328P), this function works on pins 3, 5, 6, 9, 10, and 11. On the Arduino Mega, it works on pins 2 - 13 and 44 - 46. Older Arduino boards with an ATmega8 only support analogWrite() on pins 9, 10, and 11.
The other factor is that analogWrite(255) and analogWrite(0) will revert to driving the output as a digital output. So writing 255 causes both pins to output (one as a digital output and the other in PWM mode). But writing 1 to 127 only causes the PWM capable pin to change.
From arduino's manpages:
Syntax
analogWrite(pin, value)
Parameters
pin: the pin to write to. Allowed data types: int.
value: the duty cycle: between 0 (always off) and 255 (always on). Allowed data types: int
Using an analogWrite with a value of 1 is essentially near-zero. 255 would be full voltage. You're attempting to use analogWrite() as if it was digitalWrite().
Consider using digital write instead in your code: https://www.arduino.cc/reference/en/language/functions/digital-io/digitalwrite/
As for your LED's behavior, it seems like your circuit needs to be debugged as well: Your circuit will only allow current to flow when pin 7 is on. Diodes (Light Emitting Diodes) only allow current in one direction. If you're intending to have the LED's alternate, they should all be oriented with the positives pointing toward their GPIO pin and where they meet they should be grounded with a pull-down resistor.
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);
}
I am trying to attach a servo on an Arduino (branded) Robot but not sure whhich pin to use for the bellow code.
Most people seem to recommend to use pin 9 and 10 to control the servo for arduino Unos.
However, I can't use Pin 9 because that is already used as the Slave Select pin for the LCD.
I have tried attaching it to pins TKD0-TKD3 by calling them pins 19-22 in myservo.attach(). The code runs but the servo doesn't rotate and only gets hot and/or twitches.
Could the problem be something other than incorrect pin connection?
Thanks,
-M
I have been referencing these for the Control board pin mapping:
http://arduino.cc/en/Main/Robot)
http://fabcirablog.weebly.com/blog/grappling-with-the-arduino-robot-control-board
#include <Servo.h>
Servo myservo; // create servo object to control a servo
int pos = 0;
void setup()
{
myservo.attach(19); // attaches the servo on pin 9 to the servo object
}
void loop()
{
for(pos = 0; pos < 60; pos += 1)
{
myservo.write(pos);
delay(15);
}
for(pos = 60; pos>=1; pos-=1)
{
myservo.write(pos);
delay(15);
}
}
You have this robot, right?
Arduino Robot
And you are using a classic servo (3 pins, yellow red and black cable)? If so.... Watch out. According to the schematic, the pinout of the connector on the board (e.g. TKD0) is
+5V
AD1
GND
While usually servos have
DATA
+5V
GND
So.. you have to make a short cable to invert the pins.
If that's not the problem.. Are you sure that 19 is the right number for the pin? I can't find references, but i suggest you to call it TKD0 (which is probably a macro defining the right pin), as arduino designers suggest you.