Originally published at: Bluetooth Gateways In The Field: The Ezurio Sentrius MG100 - The Golioth Developer Blog
As more deployments using Golioth’s Bluetooth-to-Cloud hit the field, we will be featuring Bluetooth gateways that are up to the task. Today we’re featuring the Ezurio Sentrius MG100, which is well targeted at industrial cellular needs.
Evaluated it, discarded it (a few years back, maybe they’ve updated it?).
I don’t know why, but for some reason the concept of an NB-IoT device being a gateway while also being truly low power has escaped every gateway maker on the market.
We did end up with the dreaded “custom hardware”. There’s nothing stopping the MG100 from doing what we did, it’s just decisions made in hardware design rendering it unsuitable for “years on battery power” for no good reason. As far as I remember, the HL7800 would have been a decent choice*, except the MG100 decided to use always-on UART between the BLE and LPWA modules, with no additional lines connected to implement a way for bidirectional wakeup between modules.
That meant that the onboard battery, instead of providing months of supply (too little for us, but enlarging the battery would have been trivial) provided days at best, rendering a capable battery-powered gateway into a wall-powered-with-UPS one.
IIRC, there were other pointlessly-high-quiescent-current situations on the board too. Single-microamp Iq voltage regulators are not even expensive anymore, yet I see so many designs where the power supply is the single largest idle load on the battery.
If Sentrius wants to prove me wrong, I’m open to be corrected. Again, my experience with them is a few years ago (read: positively ancient).
* IIRC, they have decent documentation available, if behind a login wall for no good reason. We went with nRF9160, simply because we could use the same SDK on both BLE and LPWA.
ST had a freshly released LPWA module also, but the actual SoC was only accessible through their middleware, with no AT command manual available to mere mortals, and of course the middleware was utter nonsense, and support non-existent.
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