Two new spark cores and both with different issues: one with no firmware and the other won't blink LED

The one spark core just sits with the solid blue LED (the little one) and the big LED never lights up. I’m assuming this means it wasn’t flashed at the factory. Can I just return this one for a new one? I don’t really want to mess around with it since I don’t have a JTAG.

The second spark core is connected and I’ve loaded the blink led sketch from the website onto it (this goes through the normal flow of blinking LEDs and seems to flash fine). However, I can’t get it to blink an external LED. I saw the other post on the forum about blinking an LED and it’s not my problem. No matter what pin I have it just never blinks an LED. I’ve tested the LED, I’ve used my own arduino UNO and everything works fine. What’s going on? The pin seems to be at GND and never goes high.

Here’s the latest rev of my blink program:

int led = D0;

void setup() {
    pinMode(led, OUTPUT);

void loop() {
    digitalWrite(led, HIGH);
    digitalWrite(led, LOW);

These things are really cool, but for a 1.0 it’s been a rough start considering I have two devices and both seems to have hardware/firmware issues. Hopefully both issues are easy to solve.

Hey @srcfoo , bummer about the shabby start. Let’s try two things.

For the first issue, can you see if a factory reset gets the core running again? I’ve seen this fix cores in the state you are describing. If not, yea, we can ship you new one.

For the second issue, when I first walked through this example, I was also not initially successful. For me, it turned out I had the LED wired wrong, I had wired the polarity wrong. After flipping it around, it lit right up. If a wiring/polarity change doesn’t fix the issue, you could try changing int led = D0 to int led = D7, and blink the on board LED as opposed to the externally wired LED. This would help confirm that the problem is a wiring issue as opposed to a firmware issue.

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