Communication between Spark Cores

can this device be used to create a wireless connection to send images from one device to another?

Thanks for the reply. Looks like this is another “stupid questions don’t get answered” forum.

Its also possible Zach is busy - if you check out the status page you will see he is working hard on some core design changes.

Being sarcastic is probably not going to get your question answered faster. Pretty sure they are busy :slight_smile: As the community grows, many people like myself will reach out and try to help. That is the Maker way!

I’ll try to give it a shot…

Since they have shown a demo project of WiFi security camera, it looks entirely plausible that you could send images from one Spark Core to a computer… and then bounce that image to another Spark Core that had an LCD let’s say. You may have to roll your own server for that though, which you are able to do.

I don’t believe these modules support Ad-Hoc mode so that they cannot talk directly to each other.

From the Spark FAQ: “Q: Can the Wi-Fi module in the Core be used as an access point (AP) or a wireless repeater? A: Sorry, but unfortunately no; the Core is intended to be used as a client in a standard Wi-Fi 802.11b/g network.”

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@mdwaller Sorry for the delay and @BDub thanks for stepping in! As @rockvole said, I’ve been a bit underwater with the Core re-design, just re-surfacing today and catching up on the community.

@BDub’s answer is correct, you could definitely send images from one Spark Core to another, or from one Spark Core to something else. @Zachary and I just had a long discussion yesterday on how to handle these kinds of things, and we’re making a bunch of improvements to the API. We’ll be documenting all of this in the next couple of weeks.

And also as @BDub pointed out, the Spark Cores can’t talk directly to each other - they need to be connected to an access point (i.e. a Wi-Fi router).

@zach @mdwaller I just wanted to add a bit of clarification.

  • Yes, You can send from spark to spark when connected to a standard wifi solution like a wifi router or access point.
  • You cannot however connect spark to spark without an access point inbetween them.
  • I would imagine you could even send spark to many spark or vice versa via the api.

Yes, you are correct on all points.

Changing the name of this thread to better reflect the contents of the discussion

@zach @mdwaller I can think of a lot of use cases where you might want to have a spark device as a relay, like having a device collect data at the end of the garden which is out of reach from your wifi and just throwing another spark core with a battery halfway between to relay.

Or a use case mentioned before was a row of nfc enabled parking meters where only a few have an internet connection.

Is there a hardware reason for not allowing the devices to relay or is it the complexity of writing the code ?

Unfortunately there’s a hardware constraint; the CC3000 (our Wi-Fi module) can’t act as an Access Point, nor can it join or create an ad hoc network.

However, there is another solution for use cases like these: antennas. We just added a uFL connector to the Spark Core in this latest revision (v0.2), so it’s possible to add an external antenna. This makes it possible to reach out to the end of your garden, most likely, although it may not work for the parking meters use case.

the addition of the uFL connector just made my day. thank you.

for further clarity on the CC3000 and ad-hoc mode, check out this wonderful thread at TI’s website (i lost count of the number of times they say “CC3000 does not support Ad-hoc”)

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The Ad-Hoc mode is not important for my shield. I think that the advantages the CC3000 offers in terms of easy Wi-Fi configuration are worthwhile to lose Ad-Hoc.

Just to follow up on this: based on my limited knowledge and googling ability, it seems like the wifi module on the new Photon model (BCM43362) does support creating networks/adhoc.

Is this correct?

According to the docs the Photon will support a “SoftAP Mode”. Last I checked it has yet to be determined if Spark will be exposing the Wifi AP mode for use outside of configuration but my fingers are crossed