Hi
I have build an RFID project with Arduino Uno, Ethernet shield, RC522 and a buzzer. The device was powered with 12 V and 1 A input power. But after it running for about 5 days straight, the device stopped working today.
The input power jack is working no more. Now it can only be powered from USB. The device is screwed not working well with USB either.
Could anyone help me why this happened and how to avoid it? The device is inside a box (box has holes) and room is cooled with AC all the time.
I have build an RFID project with Arduino Uno, Ethernet shield, RC522 and a buzzer.
But you are not going to share the circuit.
Have you addressed the problem of the 5V signals from the Arduino connecting to the 3V3 input of the RFID reader?
Here are the photo of the circuits.
The RFID is powered with 3.3V correctly. As I mentioned the system works but powering the arduino with 12V 1A damaged the system after 5 days I guess. What is your external power voltage recommendation?
You have powered the RFID module with 3.3V OK but the Uno output signals are 5V whilst the RFID module input signals are 3.3V tolerant. You need to level shift the signals from 5V to 3.3V
I think you should say:-
whilst the RFID module input signals are only 3.3V tolerant.
Yes as I expected, nothing to do with the power supply but the 5V signals from the Arduino killed your reader. I know their are a lot of hookup circuits out on the net that show direct connections but these are done by idiots that don't understand electronics. They take the attitude "what does it matter if it works", which sadly you have found out is only part of the story. Yes it works but for how long?
Grumpy_Mike:
I think you should say:-
whilst the RFID module input signals are only 3.3V tolerant.Yes as I expected, nothing to do with the power supply but the 5V signals from the Arduino killed your reader. I know their are a lot of hookup circuits out on the net that show direct connections but these are done by idiots that don't understand electronics. They take the attitude "what does it matter if it works", which sadly you have found out is only part of the story. Yes it works but for how long?
I have tested each parts (uno, ethernet shield, rc522, buzzer) and arduino uno is the dead one, cant upload or read anything. rc522, ethernet shield and buzzer are working fine as tested with another arduino.
So whats the comment now?
Well I stand by what I said about the RC522 it needs level conversion, if only by using a potential divider on all Arduino outputs ( but not the one Arduino input ).
Otherwise my guess would be thermal damage to first the regulator, and then that caused the thermal fuse to kick in on the USB port. A 12V input is stressing the thermal capabilities of the regulator on the Arduino. Try a pre regulator down to 9V before passing it on the the Arduino. That will split the power dissipation over two regulators.
Alternately use a buck converter to provide 5V directly to the 5V pin.
Grumpy_Mike:
Well I stand by what I said about the RC522 it needs level conversion, if only by using a potential divider on all Arduino outputs ( but not the one Arduino input ).Otherwise my guess would be thermal damage to first the regulator, and then that caused the thermal fuse to kick in on the USB port. A 12V input is stressing the thermal capabilities of the regulator on the Arduino. Try a pre regulator down to 9V before passing it on the the Arduino. That will split the power dissipation over two regulators.
Alternately use a buck converter to provide 5V directly to the 5V pin.
Thanks for the advices and I will check for the level converters too.
I will check for the level converters too.
All you need is resistors.
Is there data going from Arduino to RFID reader? If not, I don't see what the fuss is over the 3v3 RFID. No level shifting is needed from RFID to Arduino.
The regulator got stressed with 12v, the end.
Is there data going from Arduino to RFID reader?
On a RC552 then yes, it is an SPI device so lots of data signals going to it from a 5V Arduino.
These are:-
Clock
Data out of Arduino
Enable
Reset
The only signal going the other way is the Data out of the reader, you can leave that alone.