Spark fails to upload - cyan breathing LED


Trying to get very simple code uploaded (blink LED example code). Tinker works perfectly fine and I can activate various digital pins. However, when I upload code - magenta LED flashes for a while and then returns to breathing cyan - but no blinking of LED’s or indications that code has been uploaded.

Please advise - I have searched for similar issues but none forthcoming. Code below:

int LED = D7;

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

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

Try to clear current code and wifi settings from core (hold down 2 buttons and release 1 of them, keep holding other one down until led will go white (smth like that). After that set up wifi SSID and try to upload code.

thanks for the advice - unfortunately it did not rectify the situation. I will try and contact someone directly at Spark for advice. Thought of trying CLI and perhaps that would give me more useful debugging information.

I had thought that perhaps an issue with wifi could cause such an issue but then I would imagine that tinker wouldn’t work - so this is quite curious to me.

I wonder if there is any way to retrieve the code that is loaded on the spark via reverse flash process - just to try and see whether any code is actually landing on the core ?

hey @gammaphreak, one quick test would be to restart the core and make sure it’s breathing cyan.

With that, look at the core tab in the Web IDE and be sure the corrected one is :star: for flashing.

The easier way would probably be for the core to print-out or publish a variable you set in a code that is unique each time you flash rather than reverse-engineer.

anyhow, let’s try to resolve the flashing issue.

Let me know how it goes :wink:

Hi, I flashed the code from CLI and that seems to have worked.

I will try and download the IDE instead of using online IDE - perhaps might make a difference? Would you expect there to be a difference between web IDE and local


They still use the online build farm to compile code so basically the same tool, just browser or desktop based.