diagnosing problems

I need to find out if I burned out part of my mega arduino. Is there a forum I can access? (using 7 segment display, 2 servo motors, 1 lED light, 1 push button), Thanks. (newbee)

can I summon Grumpy Mike?

As if by magic the shop keeper appered - quote from Mr Ben

Need schematics of what you did to say what was wrong. :)

I think (?) I want to find out "how" to find out what is wrong myself rather than have someone do it for me. That may be wishfull thinking. There must be a a way to run a diagnostic on the board, yes? Thanks very much.

AFAIK there aren't any specific diagnostic programs. You could start with uploading the blinking LED sketch. Can you do that and does the LED blink?


You, Grumpy_Mike or anyone else can only find out what went wrong if they know what they're working with. Being on an open forum sometimes has disadvantages. People might want to help you by telling a solution to your problem without explaining it well enough. That happens from time to time over here. For instance when someone hints to where to look for a solution, and next few people tell what exactly is wrong or offer a complete code that solves the problem. The hint is given to teach you to solve your problem yourself. The complete solution will be less helpful in teaching.

So in other words, your schematics are still needed. You made clear you're not looking for someone to solve your problem, but for someone to help you to find the problem.

Thanks so much. I do not have the schematics handy. So, I will "close out???" this thread for a while until I can get the schematic, thanks for your explanation and kindness!

You could also try to describe what you did, but it's easy to make mistakes that way. Meanwhile you could try el_supremo's tip: Take the blink sketch and have it blink different ports. You could connect 2 LED's at the same time to the port, one VCC - LED - resistor - pin, the other pin - resistor - LED - GND. Those LEDs would alternate, showing you you still can source as well as sink at that port.

If you connected 9 LEDs (a seven segment (makes 8 LEDs including the dot), a single LED and 2 servo's) and used them at the same time, then you might have drawn too much current. But 7 segment displays don't need to have all LEDs lit at the same time, not even if you want to display number 8 including the dot.

Edit: typed too fast too early in the morning. Changed the way 2 LEDs can be connected so it will work as described.

wow, there are lots of helpful people!! I will try the blinking light. Also, I may wire a second Arduino identically, except with one load at a time and watch the current/voltage/power some way. Is it fair to ask a prediction about which part of the Arduino would be damaged first if I exceeded the current limit in the circuit, or does is always come back to the schematic?

You always damage the bit you overload or exceed other parameters like voltage. What makes you think you have damaged anything?

jkane: I need to find out if I burned out part of my mega arduino. Is there a forum I can access? (using 7 segment display, 2 servo motors, 1 lED light, 1 push button), Thanks. (newbee)

You haven't mentioned whether you used any resistors or other parts (mainly for the LEDs, possibly the switch) for current limiting. If you didn't, there's a possibility that you burned out those pins/ports.

Again - a schematic and code for what you were trying to do is most helpful here in helping you to find out how to diagnose this.