Hi
New to this forum and i hope i am in the right category
I have Megaboards which in conjunction with Ethernet Boards are being used to control LED lights. The board is activated by data that is fed from an application though the local network with fixed IP programmed to the board. The mega board is also programmed with the MAC address of the Ethernet board being used
When board is activated from the application it merely turns on a group of up to 10 LED lights in either a red or green colour for a few seconds. The colour, LED range, Length of time for lights are passed from the application.
The board is powered by a 12V power supply through the Barrel Connector. The LED lights are powered by their own 5V power supply and the board earth has been earthed to the LED light power supply.
This board would be activated maybe up to 100 times per day.
I implement new Mega board and new Ethernet board and they will work as expected for a couple of months and then out of the blue it will fail. Install new boards and all works again as expected.
I have replaced the board more than once just in case it was "Just one of those things", but it continues to be an issue.
The exact same system is in use in other locations and continues to work with no problems for the last 5 years.
The problem site is in New Zealand where as the older sites are Australia, if that could possibly be an issue!
Can anybody suggest what the issue could be
Many thanks in advance
Can you post an annotated schematic of your system, be sure to show all transient protection for both the mains and low voltage. What is it housed in and what are the ambient conditions? This should help us help you. Also post links to the power supplies you used.
Hi
The power supplies are housed in a PVC Electrical Junction Box as are the boards and network switch in another. The environment is not hot but can be dusty hence the PVC boxes.
The 12V power supply similar to
The 5V 40A Power Supply
Wiring Diagram supplied to electrician and you will note that it says that it needs to be as necessary. Electrician has not installed any cir4cuit protection except for what might be in the power supplies.
The board that continues to fail is marked as Arduino Mega 1
Thank you for having a look
Is it 60 days? Perhaps 50? In this case could it be related to a timing calculation with millis()?
Is it the Mega or the ethernet board that fails, or are both non-operational after the failure?
Upon a closer look into the dates
Second board lasted 22 / 23 days
third board lasted 48 /49 days
first fail, the Mega was replaced and the Ethernet was OK. Was able to test this as i was on site.
2nd and 3rd replacement both the Mega and ethernet boards where replaced due to the site location being away from home and i was no longer near site
Are you running the same type 12V supply in all installations? A slightly higher voltage may be overheating the onboard voltage regulator.
get one of the failed devices and take a close look what failed, otherwise you'd be chasing ghosts
Thank you for your input
I thought the input voltage limit is 20V?
That being the case do you still think a over voltage problem could exist
I have already asked the site to return the faulty boards back to me for investigation.
Problem is they are in New Zealand and i am in Australia, so it takes a while
I appreciate your suggestion
Thank you
Definitely is a problem if the voltage regulators are loaded all the time....The regulator has to burn of more power in heat the higher the voltage.
Are you using genuine Arduino Mega boards, or third-party clones?
Did you use the same source of boards in the Australian installations and the New Zealand installations?
That makes sense as a possibility. Would the use of a Buck Converter to reduce the input voltage to 7.5V be a possible remedy. The other sites i have are in fact wired in this manner.
Yes both the Mega board and the Ethernet boards are genuine Ardunio products.
Boards have all been sourced from the same Australian supplier for all sites.
How does the failure manifest?
Just in case, this simple circuit will tell you is there was a power failure, sort of an electromechanic flip-flop. With some electronics or Arduino control you can monitor if power went below a given level.
Although the regularity (vs randomness) of the failures makes me think of a software issue. But, if they all are using the very same sketch...
Sketch is basically the same for all sites. The only difference is the following
- Mac Address for the ethernet board
- Fixed IP Address being used
- Local Gateway address in use
- Local Subnet in use
Items 2, 3 & 4 are obtained form the site IT people and site specific
I believe the suggestion in #12, That is the way I generally build my stuff. I like the Analog regulator as it gives additional filtering on the power supply. I also monitor the incoming and outgoing voltage. A few years back I had a buck fail, it got damaged during a storm. That told me to replace it ASAP.
I read lots of guessing, have the failed boards all have the same failure and did you actually track down the failure point or component?
Waiting for boards to be returned from site in New Zealand for inspection
