Looking for faster 2-way communication with device



I am trying to get faster 2 way communication between my device and my android phone.

I have an Arduino with a SIM800L that is running a CIPSERVER on port 4010.
I can send commands by sending cloud to device messages using Hologram’s API and I can read the device responses through the API. Everything works fine but I would like to improve the response time for sending commands and receiving replies.
This process is quite slow. It takes about 10-20 seconds to send a message and obtain a reply from the device.

My question: How can I connect directly to my device so that I can have instantaneous 2-way communication instead of going through the API?
The IP obtained by issuing the command CIFSR is a private IP 10.x.x.x behind hologram’s cloud.
Is there a way to get a public IP to my device, so that I can communicate directly to my device?

Is a WebHook a direct path to my device? But it seems to me like another path going through the API, I haven’t tried that yet.

Thanks for any help


Cellular allows connectivity in a wide range of areas, but does not really provide “real time” control or interfacing. The power and data required to maintain an “always connected” option would be quite costly, so each time you are interfacing to your device you must go back through the various levels of infrastructure. Your phone is doing the same.

Could you tell us more about your application? If you’re trying to go from a phone to a device, is there a reason you chose cellular over wifi/bluetooth? Also why you chose a 2G device like the SIM800L over a newer modem? Happy to help getting your connection a bit more snappy, but curious about your overall context.


My application is to control the remote starter in my car (lock, unlock, start, stop). Mainly to remote start my car from miles away while I am on the public transit on the way to where I parked my car (ahhh those harsh winters here in Canada). Later I am adding a temperature sensor and possibly a Can-bus interface (once I figure out how that works).

Newer modem? Well I got it for dirt cheap, about 5-10$ but I don’t see how just a few bits of information may be significantly faster with 3G or 4G … although I am interested in testing out the newer Dash on LTE Cat-M1.

The 10-20 seconds delay is not a deal breaker at all, it only means that I am looking at my phone for a while to see if the command was accepted and that my car has actually started. I just taught maybe it could be better somehow.
When I send a message via Cloud Data from the Hologram Dashboard, it takes 2-3 seconds and the command is executed on my device, it would be great if all commands and responses would be quick like this.
Even tough the device immediately responds, it takes another 10-15 seconds to appear in the hologram console and to be able to read it via the API. If I send the command via the API, it seems to add another 5 seconds.

Power consumption is really low, I measured the continuous usage at about 60 mA 12V (maybe I measured that at 5V, I forgot). That’s with the CIPSERVER command executed and always listening. It shouldn’t drain the car’s battery unless I leave it parked for 2-3 months without using it.

I was wondering if I could setup the modem to obtain a public IP address and have it listen there?



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