Hi:
I wanna use mesh pub/sub to transmit JPEG from endpoint to gateway and then gateway transmit the JPEG to cloud. Is it possible?
The mesh publish just allows up to 255bytes. If publish function works once per seconds, and the JPEG image is 70Kbytes(1080x1301) (I can divide the image file into several data chunks), it will take 4.68 minutes to send this image.It’s just that this process takes so long, not to mention the gateway uploading images to the cloud. And transferring this image may consume a lot of computing speed of the board.
So, is there some possible way to implement my thoughts?
@sgjtian2, you can do direct UDP communications with somewhat lager payloads. I believe @rickkas7 has an example of this. Also, I don’t believe Mesh pub/sub are not limited to one-per second like Cloud pub/sub. However, being delivered via UDP, there is no guarantee that every message will get through. So you would need to implement a simple ACK mechanism on the gateway side.
On thing to note is that Mesh bandwidth is 20-25KBps at best. And delivery time will be impacted by Mesh and processing latencies. So in an ideal scenario using direct UDP (with ACK), your full payload could be delivered in under 10 secs assuming Mesh traffic is not loaded by other nodes. With Mesh pub/sub, assuming a publish/ACK round trip time of 100-200ms, the payload could be sent in 30-60 secs. However, this is a theoretical and would need to be proven out.
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