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Topic: Re: cant even turn LED on (Read 848 times) previous topic - next topic


from what it seems you are not connecting your breadboard to ground!
you need to connect the blu stripe, right under the blu minus sign to arduino common ground!
if you look on the arduino board in the "POWER" section there is one pin that outputs 5V, 2 pins called "GND" which stands for GROUND, and a pin that outputs 9V.
You need to connect one of the two Gnd pins with the rightmost blue line in your breadboard (According to your diagram)...so that the 470 Ohm resistor connects to ground and closes the circuit

as for the ledPin = 5
it is probably speaking of the DIGITAL pin 5
the other "5" that you might be referring to
belong 1 to the POWER section and it just says that it has 5Volts coming to that pin

and the other belongs to the ANALOG IN section
which as the name says are mainly used to send Analog data to the microcontroller.

do you have clear the difference between digital and analog ? :) sorry for the question :)

hope it helps
look under the tutorials for reference image




You picture seems to be right, as long as you also connect the plus and minus line on the breadboard to the arduino (plus = 5v and minus = ground (gnd)) and you can not use digital pin 0 and 1, these pins are used as the Tx and Rx, it is something similar like the serial port, considered to communicate with a other boards or a mp3 player etc., I realy don't know what this is but what you should no is: it don't work as an normal input or output.

To the pins: if you use an pin as an output, then it is always an digital pin (on the one side of the board is written analog on the other side digital) so you have to plug it for example on the digital side to pin nr.5

Furthermore you have to mind: the led have a polarity, you know, it works just in one way. So you have to try out which leg have to be on the plus side and which one has to be one the minus side

Hopefully I did wrote something wrong here, good luke?.


Mar 09, 2006, 11:41 pm Last Edit: Mar 09, 2006, 11:45 pm by beltran Reason: 1
there is a very simple and immediately satisfying way to check if your board is working properly and that is:

put a led between pin 13 and its closest pin called GND
which stands for ground.
just put the led's longer leg (+) inside pin 13 and the led's shorter leg (-) inside GDN.
You don't even need a resistor because the board already integrates one that goes into pin 13. (achtung: this is the only pin that has this feauture)

once you've put the led like that you can press the reset button on the board to chek if it's working...it should blink 2-3 times to tell you that the bootloader is correctly installed in the microcontroller and that it is waiting for you to send him a program from the computer.

- open the simplest example...the "led blink" inside your arduino software IDE (check in tools > serial port if it's addressing the right COMport where your arduino is connected)
- if you read the program you should see that it is addressing pin13 for the led
- press the "verify" button to compile the program
- press the reset button on the board
- and right after press the upload button on the IDE
- wait untill it has been properly uploaded and enjoy :)



You are all so right. thankyou for all the help..

it is working fine, i didnt realise which ones are ground.

i have one question now.... i am using wiring board. and it is different to arduino slightly. on the left of the usb port, i have 4 pins similar to the power pins on arduino. except on wiring they are: VCC - GND - GND - 9-15V

what does VCC mean, does VCC mean 5V.

i need to use 5V pin for the photoresistor example, but cant find 5V on wiring board?



Mar 10, 2006, 07:25 pm Last Edit: Mar 10, 2006, 07:27 pm by beltran Reason: 1
test it with your brand new voltmeter and see it for yourself ;-)

(remember to connect it to ground)

VCC stands for Voltage Common Collector



Thanks - VCC is 5v i tested with voltmeter - thanks!

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