i connected id20 as in the diagram here http://wulfden.org/TheShoppe/freeduino/ID12_schem.jpg and used the code in this link Arduino Playground - ID12
but i am getting no output. using multimeter i found that two ant pins from id 20 are shorted internally . is that the problem? please help
note: now i am finding that vcc gnd and data pins to are short ! please help
using multimeter i found that two ant pins from id 20 are shorted internally . is that the problem?
No .... the antenna of an RFID reader is a simple coil with a few turns on it. A simple multimeter will think this is a short.
You can't just measure the DC conductivity of an active device like this with a multimeter and it make any sense.
please reply. things are getting worse. when powered on multimeter shows that vcc gnd and data pins are shorted.....................
i am gettin tensed i spent 35$ for this please help
when powered on multimeter shows that vcc gnd and data pins are shorted.
You can't make measurements with a multimeter when it is powered. In order to test for a short the multimeter puts power out and measures it coming back. If you put a multimeter set to measure resistance onto a source of power it will show up as a short because it is measuring the power in the circuit and thinks it is it's own power being returned.
Now how have you wired it up? Those links did not show how to wire it up. What tags have you used? Try connecting an LED and 1K resistor to the output does it flicker when you present a tag?
yeah i soldered everthing as shown including led and 1k res.
the short shows up only when the chip is connected to power.
if not there is no short circuit .
Can you please tell me any method of testing whether it still works ?
and tags i used 16mm tags http://www.sparkfun.com/products/9417
yeah i soldered everthing as shown including led and 1k res.
So how do you know what way round to solder the LED, the schematic doesn't show this.
So go round with the multimeter and measure the voltage on each pin, is it what it should be? If you measure 5V on the power input then you have not got a short.
Are you receiving anything? After the :-
if(Serial.available() > 0) {
put a
Serial.println("got something");
to see if any data is being received.
Then post a clear photo of what you have go so we can check you haven't miss wired anything.
Thanks a lot for all your help. you had made my day.
Some mis soldering ruined everything . i got output once. so i am going to get my brother solder it again tomorrow.
happy that my money didn't go to waste.
I will post the picture of my soldered components tomorrow.
thanks a lot again.
one more addon: the circuit works like a charm if i connect a resistor between (3 &4 terminals) antenna is it okay to continue like this or will it damage the circuit?
the circuit works like a charm if i connect a resistor between (3 &4 terminals)
What value?
two corrections : the pin number was 4 and 5 . and the valueof resistor i used is 1kohm.
sorry.
And atlast after resoldering everything neatly in a bigger pcb. it works fine. but the 1k resistor is still there betwen pins 4 & 5. taking it the circuit fails.
