Spark does not receive Flash from SparkIDE

I am working with Spark now for around 48 working hours. During this time I often had the problem that the Spark would not receive a flash from the Webinterface (SparkIDE). The LED shows breathing cyan but does not do anything. Sometimes it shows a blinking green for one or two minutes, then goes back to breathing cyan. I can torture the Flash button, but nothing happens. The only solution is a factory reset which I did like 30 times in the past 24 hours.

Is this normal behaviour? Or is it my fault? Any ideas or suggestions? It is a pain in the ass if I cant flash the Spark reliably from the SparkIDE.

@zach @mohit

u.Fl or chip antenna?

blinking green sounds like your wifi connection got dropped. How’s the distance between the core and router?

Correct me if im wrong :slight_smile:

Chip antenna. The distance is like 50cm to the router :wink:

But even if it has breathing cyan, it often wont receive a flash.

What’s the antenna you are using? :smile:

Something in between the core and router? wall maybe

Chip antenna. Nothing in between. Just good fresh air :wink:

Maybe you can use this : and test if you core is actually connected to the Spark cloud.

If you are unable to read anything from it even though it’s breathing cyan… You probably face the same CFOD issue :slight_smile:

This might be better!

Using this code and flash it:

int LED = D7;
int temperature;

void setup() {
    pinMode(LED, OUTPUT);
    Spark.variable("temperature", &temperature, INT);

void loop() {
    digitalWrite(LED, HIGH);
    temperature = 188;
    digitalWrite(LED, LOW);
     temperature = 0;

You can tell what value you should be getting depending by looking at the led. :slight_smile:

That way you know if the core is really give a true value

I will try that in a second. The crazy thing though is, that the Spark does send data to my mySQL database even when the led is flashing green (which should mean that it is establishing wifi atm).

But to Flash it, I have to do a factory reset everytime before flashing.

Your Mysql is local?

No its online. I push the values over through an online php script using GET and params.

Hm. What would happen if the flash is sent while the Spark Core does a “Delay(xxx)”? This could be the solution, right? Does the Spark freeze while Delaying?

Might be explained here, right?

Hi @kaul,

That could be an issue, very long delays can knock the core offline entirely and make it difficult to flash the core over the air. We’re working on a fix for this however, so it won’t always be the case.

If stock Tinker is staying online and is responsive on your network, but your custom firmware is having problems, it might be something like a Delay, or code that’s causing a crash. These guys are really good at spotting those! :slight_smile:

If stock Tinker is having problems on your network, we’re investigating a problem that’s caused by high ARP traffic on large networks that the CC3000 doesn’t handle well.