I pulled my Arduino set out of storage yesterday and was very upset to find that it is not working for some reason. Before I explain the problem, let me explain the situation.
Hardware (all DFRobot):
Arduino Mega 2560
Arduino Mega 2560 4x-platform breakout board
GPIO Expansion Shield V1.0
I/O Expansion Shield V7.1
8 Channel 5V Relay Board
4 LED/Resistor set up
1 digital speaker
1 digital humidity/temperature tester
7 analog chemical air chemical testers
In this 4th photo, the two analog pin sets in use right in front are the ones I remove in order to gain control again. if those are plugged in then it doesnt work. It has nothing to do with those pins specifically, If I remove any two it works again, those ones are just easiest to remove to get it to work:
Explanation of project:
This is basically a test station, where I can hook up what ever I want and see how it works and then move onto another peripheral piece of hardware and make them interact. I went with the 4x-platform breakout board as to maximize I/O space. Once a project is done, I Velcro band them together as to not get them confused and move on.
Explanation of problem:
When I plugged the Arduino into my PC the first time, the lights came on the Arduino and then after about 15 seconds it powered down and the lights went off. My PC did recognize it while it was powered up and the port option under tools in the Arduino IDE was available and I could select the port. After the power down and problems I realized something must be up.
I considered the fact that maybe the Velcro was constricting the wires and causing them to short circuit through the rubber insulation, but couldn't find any info on that online.
After this I decided to cut the PC out of the equation and try just plugging it into the wall, 1st, via USB to 5V1A wall charger, it stayed on for a few seconds and then turned off, 2nd with a 5V2A wall charger, same scenario, 3rd via the barrel jack with the same wall chargers, with no success.
I undid all of the wire bundles to rule out a short circuit, which it did. I then found out after much trial an error that if I removed any 2 of any analog or digital wires, the lights would stay on and it would work.
Now, with two cables removed so it did not lose power, I plugged it into my PC and am now able to program it again and see it in the port in the IDE, but as soon as I plug in another 2 analog or digital peripheral devices it will lose all power and stop working.
I also tried plugging my DFRobot Beetle micro-controller in with the same USB cable and it worked perfectly. I also tried resetting the micro-controller, to no avail.
Conclusions so far:
A short between rubber insulation at 5v is extremely unlikely
one would think that if a mega board was designed to have so many I/O pins you could actually connect to all of them with out any problem.
Since this happened on both the PC and wall charger scenarios, and the problem seems to be associated when disconnecting any 2 sensors, the problem is most likely at the micro-controller level.
Questions:
are all the peripheral devices draining the board so much that the USB port on the PC or wall chargers cant handle it?
How do I provide enough power to the board if this is the problem?
Or is this simply faulty board?
If it is a faulty board, what causes this and how do you avoid it?
Just to clarify, looming the wires together into bundles is OK right?
Finally, any help would be really appreciated, this is the first time this has happened and it sucks.