Did I burn my Core? (connecting Arduino to Core)

Getting Started
1

Hi

Could someone help me figure out how/if I have burned my core?

symptoms:
Spark Core is very hot to touch
On-Board LED is not lighting up
No devices detected via USB when using “particle setup” in CLI

My Setup

(a) Arduino Uno+Wave Shield, powered by laptop USB
(b) Spark Core on breadboard, powered by laptop USB

I have one digital pin on the Arduino (~5V) connected to D7 of the Core, and GND on the Arduino connected to the GND of the Core. I tried pull down the digital pin on the Arduino by setting D7 on the Core to LOW, triggering a sound playback. This works for a while, but now the on-board LED on my Core is no longer lighting up, the Core is extremely hot to touch, and no longer recognized when plugged in to USB. Can someone tell me how/if I burned my Core with this setup?

Thank you,

2

Was D7 of the Core set as an input? If not the core could have been trying to drive D7 high and the arduino could have been driving it low creating a short.

I have seen this on other designs if people are not paying attention and the chips get very hot and can burn out.

3

@dan6684, if you disconnect the Core entirely from the Arduino and have nothing connected to it except USB for power, what happens on the Core?

4

my D7 on the Core was set to Output and the pin on Arduino to input_pullup… I was trying to simulate a button press
on the Arduino pin by setting D7=LOW.

Arduino:
pinMode(buttons[0], INPUT_PULLUP);
core:
pinMode(D7, OUTPUT);

5

I disconnected the Arduino… the core still heats up within seconds after connecting to USB power and becomes too hot to touch :frowning:

6

@dan6684, if you have a voltmeter, I would ask that you (quickly) measure the voltage on the 3.3v pin with USB plugged in. There is a possibility that the 3.3v regulator is shot and that’s what is getting hot.

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7

I can still see 3.3V at the 3.3v pin

8

@dan6684 Can you tell which part of the core is getting so hot? Is it the small black IC on the back (the regulator) or the large silver box on top (the CC3000)? The CC3000 does get warm but shouldn’t get “hot”

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11

Hi Harrison, the CC3000 is really hot (my finger can endure about 5 seconds )… the regulator is even worse (can’t even hold for two seconds)…

12

@dan6684 do you have a bench-top power supply or an Arduino UNO which you can supply 3.3v? If so, go ahead and unplug your core, let it cool down, and then connect 3.3v to the Core’s 3.3v (from a external power supply for the Uno’s 3.3v) and ground. The core should power up and the voltage regulator on the bottom should be cool. Let it sit and see if the CC3000 gets hot. Note, do NOT connect USB during this.

What else do you have your Core connected to? What external components? (other than the Arduino)

1 Like