My project consists of a 16x16 led matrix controlled by an arduino Uno
I have the arduino uno powered by a 9 Volt battery which is connected to the AC barrel port
Connected to the matrix through data pin 7, ground and 5.5v
The matrix is powered by 2 AA Batteries wired to the main ground and live lines
All wires are secured with heat shrink then electrical tape to keep the wire bundles together...
This setup workes flawlessly for several hours while programing the matrix itself, i unplugged evreything for a lunch break. When i plugged evreything back in... the live end from the batteries to the matrix started smoking... the coating on the live wire coating melted off within seconds.
I checked all wires non where touching or shorting out on each other, the matrix seems to still work when i quickly tested it with just the arduino 5.5 volt pin
What did i do wrong? Im scared to run the change out the live wire and plug batteries in again.
Should i trash it all and just buy a whole new matrix and battery holder... im paranoid as i had a house fire when i was very young
Looks like your wiring techniques leaves a lot to be desired.
Melted wires implies a direct short in the wires.
The Arduino 5v pin should not be used to power large loads, ~400ma might be okay (non inductive loads).
Always monitor the temperature of the on board voltage regulator.
The electronics might be still good.
Try a simple sketch then add components one at a time.
Equipment ruined varies directly as experience.
Edit:
Looks like 3.3v is connected to 5v on the display, why?
I assure you i did not look like that to begin with lol... i just put the wores together quickly to take a picture...
I removed the orginal melted wiring that was fully soldered and shrink wrapped i didnt ger a picture of it sadly before it melted.
It is plugged into 5.5v its just the labeling on the board is not really lined up with the sockets on the arduino itself.
I know heat and smoke mean a short... but with the wires fully protected from touching each other does that mean theres a short in the matrix itself? Should i try to re-wire evreything properly and try again?
Edit: it is plugged into the 3V in the photos my mistake... again i just placed the wires to show i didnt actually run it with exposed wires like that
“Don't forget, with 256 LEDs, you could use over 15A of current if you turn on all the LEDs on to white (which we really do not recommend because we don't think the flex PCB can handle that much current). Try to keep the current draw at undrer 5A, you can use our 5V 4A or 5V 10A power supply. For portable use, if you are drawing less than 3A, try out this 5V@3A UBEC.”
The AA's are connected to the middle live and ground wires
Turns out something is wrong with the battery holder itself! It will smoke connected to nothing, being the batteries are a super tight fit maybe i poped something out of place in the battery holder itself
Im going to solder the wires, and heat shrink them with a new battery holder tomorrow
First, take a paper towel and wipe off the lens of your phone's camera!
Then carefully draw (using a pencil, eraser and paper) a diagram of each connection and pin you have in your circuit.
I suspect the problem of "smoking batteries" is due to the 9 volt battery feeding voltage into the double-a's., essentially trying to recharge them up to 9 volts! This will result in overheating and eventually burst batteries. As long as they are alkaline batteries, you don't have to worry about fire (unless the hot batteries are sitting in a pool of accelerant!) Show us your connection diagram, and I'm sure the problem will reveal itself.
