Hi there,

Has anyone out there worked with the Arduino and the APDS9002 miniature surface-mount light photosensor by Avago technologies? Or maybe something similar?

The APDS9002 detects ambient light to control display backlighting. I'd like to see how others have used these sensors, or similar ones, before I start my own project.

Thanks!

hmmm. I don't know how to determine what an appropriate resistor would be. What do you think would be an appropriate resistor?

OK. Looks like I'll need to do more research on transistors. Thanks for the tips and head start.

Moving forward it's crucial that I determine the specs of the LEDs I have. Earlier in this thread i was told this:

"In the absence of a data sheet the only way to get the forward voltage is to measure it at a set current."

I'm unsure of how to do this. Do I use a multimeter? I'm hoping that someone out there could tell me how to measure the forward voltage of these LEDS. I bought them a few years ago - can't recall from where.

Thank you!

Is this an appropriate transistor for an led arduino project with an additional 12 volt battery supply?

TRANSISTOR,2N3906,PNP

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=2094135

Thanks again!

Ha ha ha I hate it, too!
It never comes in handy. At one point, I had two of them and it was double the disappointment.

That said, can I use the one still have to determine what kind of LEDs I have?

Thanks for the clarification about the transistor symbol.

Cheers,
JLK

Hi again,
After reviewing the schematic for using an additional power supply here:
http://www.thebox.myzen.co.uk/Tutorial/Power_Supplies.html

I have two additional questions.

1. I have a 12 volt DC battery, so the relay I need is a 12volt DC relay. Correct? Like the one here http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=2094135

2. In all three schematics, I don't know how to read the thick black bar that is in between the resistor and the diode. Does it represent a component or is it just symbolic of part of the diode?  

Thanks so much everyone!

JLK  

"In the absence of a data sheet the only way to get the forward voltage is to measure it at a set current."

I'm sorry, I don't  know how to do this. Could you explain?

I have one a low-end voltage meter like this one: http://www.radioshack.com/product/index.jsp?productId=2103174

Thank you for "The Box" - it's a great resource so I tweeted about it.

JLK

Thanks MikMo,
Based on your post I have other questions.

These three packages of LEDs I have - I need to determine their forward voltage more accurately. Can you suggest a way to do this or an online resource that would help?

Is there an online resource that could help me determine how much power I need? There's likely a formula I should have memorized by now, right?

I've programmed the arduino to make the lights blink to a customized pattern. Because I want the arduino to turn the lights on and off on cue, I'm unclear about how to integrate an additional power source that likely will always be on/high. Any suggestions?

Thank you!

Hello Everyone,
Thanks in advance for any help you can offer. It's appreciated.

http://led.linear1.org/led.wiz

I found this LED series/parallel array wizard recently. According to it, I can power 70 LEDs with 9 volts. Is this legit?

If 9 volts can power 70 LEDs does this mean that an arduino board, powered by a nine volt battery, can power a series of 70 LEDs?

The wizard allows you to use the color of your LED to determine the diode forward current. Is this a safe bet? I have three packages of LEDS I purchased long ago-one red, one green and one yellow and I don't have the specs for them. The packages just say 3RD, 3GD and 3DY.  

Be well,

JLK

Hello,

I'm having some problems doing what should be a simple task. I'm just trying to hook up a Parallax pir sensor to the arduino - just three pins - GND, v+, and output. When I connect the two units, the sensor appears to drain the power out of the arduino - the arduino "on" led goes completely dark. I've tried connecting the sensor to the arduino when connected to a battery and when connected to my computer. Same results both times.

I have heard that these sensors sometimes don't work, but before I go an buy a new one I wanted to check in.


Here's a link to info about the sensor:
http://www.parallax.com/Store/Microcontrollers/BASICStampModules/tabid/134/txtSearch/555-28027/List/1/ProductID/83/Default.aspx?SortField=ProductName%2cProductName

Thanks for any help you can offer.  


jlk

Great. Thank you!

Thanks for the reply!

I just did an experiment based on your suggestion - and got it to work! There is only one obvious ground on the daisy mp3 and it is the same one that connects to the ground connection of its battery pack. My question is this: is it OK to have a wire from the arduino connected to the same pin that also connects to the Daisy battery pack?

Thanks,
JLK

Hello everyone. I'm working with the Arduino board and the Daisy MP3 Player (purchased through Make Mag - info avialable here:http://www.teuthis.com/html/daisy_mp3.html )

The code below is written for the Four-Four Mode and does play track 0001, however it only plays it for about one second.

According to the Daisy manual the B0 pin on the Daisy "is used to strobe in the track section." Later it says "momentarily bring B0/INTO low. I think this is where the problem lies in the code below. I couldn't get track 0001 to play at all when I just set B0 to LOW, that's why this code also sets the b0 to HIGH. When it is set to high it plays the correct track but only for a moment. I want it to play the track for the whole duration of the track.


Since I wrote the info above, I've tried a few other approaches. It seems that I am unable to get a "Low" or ground signal out of the arduino.


Thanks for any help you can offer. Cheers! JLK


                
 //* PLAY Composition 00001
//*code by Jenn Karson


int  Pin10 = 10;                //arduino pin 10 goes to Daisy MP3 pin 0
int  Pin9 = 9;                 //arduino pin 9 goes to Daisy MP3 pin 1
int  Pin8 = 8;                 //arduino pin 8 goes to Daisy MP3 pin 2
int  Pin7 = 7;                 //arduino pin 7 goes to Daisy MP3 pin 3
int Play11 = 11;              //arduino pin 11 goes to Daisy MP3 B0




void setup()                    //run once, when the sketch starts
{
    
  pinMode  (Pin10, OUTPUT);    
  pinMode  (Pin9, OUTPUT);
  pinMode  (Pin8, OUTPUT);
  pinMode  (Pin7, OUTPUT);
  pinMode  (Play11, OUTPUT);
  

}

void loop()                   //run over and over again
{                            // Play track 0001  
  digitalWrite(Pin10, HIGH); // Dailsy MP3 Binary Track Choices
  digitalWrite(Pin9, LOW);
  digitalWrite(Pin8, LOW);
  digitalWrite(Pin7, LOW);
  digitalWrite (Play11, LOW);
  digitalWrite (Play11, HIGH);    
    
  
}

Will do. Thank you!

 

Greetings:

Has anyone worked with the arduino and the Sensirion SHT11 humidity and temperature sensor? I have working code for basic stamp but not the arduino.

Thanks for any help you can offer,

JLK