Show Posts
Pages: [1] 2 3 ... 5
1  Using Arduino / General Electronics / Re: Using 750ma leds with arduino on: December 03, 2013, 05:04:02 am
Actually its 750ma per led, and because they are blinking it will not reach the 19A.
I do understand the use of a transistor to drive the led, but what is really confusing me is that on the project both the positive and ground lines are connected to arduino ports.
Meaning that to turn on a led I will need to drive the positive port high and the ground port low.

I do I deal wiht driving the ground port low using a transistor or a IC ?

Thans for the replies.

José
2  Using Arduino / General Electronics / Using 750ma leds with arduino on: December 02, 2013, 03:52:30 pm
Hello
I am trying to do this instructable, a simple 5x5 led project using timerone library.
http://www.instructables.com/id/Yet-Another-Daft-Punk-Coffee-TableDisplay/.
Actually I am using this principle to do a led piramide for my garding during x-mas.
The leds I am using are rated with 750ma mutch more than arduino ports can use.
I know I can use transistors or the uln2003a IC do drive the leds from an external suply.
But I dont know how to connect it.
Can some one point me to the right direction on how to adapt the circuit ?
Or any other project that uses the same principles I want to use.
Any help would be apreciated.

José
From Portugal
3  Using Arduino / Programming Questions / Re: Relay turns on but not off (SOLVED) on: September 25, 2013, 02:39:07 pm
Yes I had both grounds toguether, but the system only works if I have both the ground and the + wires connected to the power suply of the relay.
But its working now so I am happy with it


Later I might try to understand what was wrong.

José
4  Using Arduino / Programming Questions / Re: Relay turns on but not off (SOLVED) on: September 25, 2013, 01:47:32 pm
I was powering the relay and the arduino with separated power suplies.
The relay is connected to a pc Power suply and the arduino to the USB port fropm the pc.
Connecting the arduino to the same power suply as the relay the system turns on and off as supposted.

Thanks for the help

José
5  Using Arduino / Programming Questions / Re: Relay turns on but not off on: September 25, 2013, 01:12:11 pm
Hello
Thank you to you all.

I have solved my problem, it was an energy problem.
Problem solved.

Thanks

José
6  Using Arduino / Programming Questions / Re: Relay turns on but not off on: September 25, 2013, 03:59:56 am
Hello
I did some testing with the blinking example and the relay was turning on and off.
I did not increase the loop delay higher, this could solve the problem.
Regarding the on state with the digitalwrite High, at this point this is not an isue since it should turn on and off as the sensor detects motion.
Now I am at work, later I will do the blinking example and check if all is connected right.
Later I will post further test results.

Thanks for all the help.

José
7  Using Arduino / Programming Questions / Re: Relay turns on but not off on: September 24, 2013, 05:32:06 pm
Yes, exactly.
So the sensor is sending the right signal when it doesn't detect motin, the arduino is changing the stat of the relay, but this one is not changing.
The led onboard gets less brighter, but I don ear the click on the relay and the output ( leds) stay on.

José
8  Using Arduino / Programming Questions / Re: Relay turns on but not off on: September 24, 2013, 05:19:00 pm
Sorry I copied the code form the example,
I have the sensor connected to analog 3, I am sure

José

Ps. I already changed the comment in my program
9  Using Arduino / Programming Questions / Relay turns on but not off (SOLVED) on: September 24, 2013, 05:12:07 pm
Hello to you all
Not sure if this is the righ place to place the question

I have a circuit with one RC-SR501 sensor

controling  one channel relay



My code is

Code:
/*
  AnalogReadSerial
  Reads an analog input on pin 0, prints the result to the serial monitor.
  Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.
 
 This example code is in the public domain.
 */
#define rele 2
// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  pinMode(rele, OUTPUT);
  digitalWrite(rele,HIGH);
  Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A3);
  // print out the value you read:
  Serial.println(sensorValue);
 if(sensorValue>500){

  digitalWrite(rele, LOW);
  Serial.println("O rele ta on");}
else
{  digitalWrite(rele, HIGH);
  Serial.println("O rele ta off");}
  
  delay(300);
}       // delay in between reads for stability

I now the output of the sensor is digital but due to the long wire and the output of the sensor being 3.3v I decided to use it in an analog input.
The readings are ok, and the sensor changes state as it detects motion.
When the program starts the relay is off, as it detects motion it turns on, but it doesn't turn off, even if no motion is detected.
Should I place a pulldown resistor on the digital out chanel nº2 ?
I tought the relay shield already had this pulldown resistor.

Hope I was clear enough.

Any help is apreciated.

Thanks in Advance

José

10  Using Arduino / Motors, Mechanics, and Power / Re: Setp motor and L298N getting very very very hot on: August 27, 2013, 04:13:07 pm
I was just reading about this and this is great. All my needs are fullfiled now.
But this is only for bipolar motors right ?

José
11  Using Arduino / Motors, Mechanics, and Power / Re: Setp motor and L298N getting very very very hot on: August 27, 2013, 03:34:18 pm
Hello
thank you for your quick reply. That as hat I thinking but I eeeeeee2yhasanted confirmation.
Can you please tell me if this is hat you have sugested ?

http://www.ebay.com/itm/200941266821?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Thanks again
José
12  Using Arduino / Motors, Mechanics, and Power / Setp motor and L298N getting very very very hot on: August 27, 2013, 02:36:03 pm
Hello
I have search the forum but I asn't able to find a clear solution for my problem.
I am trying to use this motor:

Motor Specs here: http://www.mitsumi.co.jp/latest/Catalog/pdf/motor_m49sp_2k_e.pdf
ith this controler L298N:

Connected as indicated here


I am using the one revolution from the stepper library.
I have tryed to difrent poer suplies: 12v and 20v

In all situations both the motor and the controler are getting really very hot.

Is it possible to control this motor ith the L298N ? If yes hat am I doing rong ?
If not hat controler should I get in order to use this motor ?

Thanks in advance for all the help.

José from Portugal
13  Using Arduino / Networking, Protocols, and Devices / Re: i2c over LONG distance. or other interface? on: March 14, 2013, 11:11:34 am
Hello orionsbelt0
Did you find a solution for connecting two arduinos over a long distance ?
I would be interested in such solution too.

José
14  Using Arduino / Sensors / Re: Max31855 Internal temp strange value on: January 28, 2013, 04:30:19 pm
Thanks for the reply
Today I figure out that something is wrong, maybe with the max31855.
I will check and get back with news.

Jose
15  Using Arduino / Sensors / Max31855 Internal temp strange value on: January 27, 2013, 01:57:13 pm
I am using a shield with the MAX31855 with the library from adafruit with my arduino duemilanove.
Using the library example "serialthermocouple" I have measurments of the internal temp of the max31855 about 15 degrees higher than it is supost to be
Using a mixure of water and ice that has a temp o 0º I get measurments of the temp os the thermocouple about 15 ºc.
Does this means my shield is broken ? Or am I doing something wrong ?

Thanks in advance

José

Pages: [1] 2 3 ... 5