uMesh – A self-contained, battery operated ESP32 module

Jarrett published a new build:

I’ve been working on an ESP32 module. Part of the problem I’ve been seeing with inexpensive IoT dev boards, is that the design around the power system hasn’t been very good. Here’s my attempt to fix that. This is a battery-ready module with a proper lithium battery charge circuit, lithium battery protection circuit, power supply, and antenna, all in a 1 inch by 1 inch package.
The goal is to have a tiny, inexpensive module that can immediately accept a battery and be deployed in the field, along with 30 of its mates.

See the full post on his blog.

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  1. The most important piece of information is not there — what is the power consumption in different modes? He showed the board with a small battery — how long will a sensor node last? No numbers, nuthin’. He showed off the board with a _small_ Lipo and no performance data? Strange, don’t you think, especially when he talks of deploying nodes in fieldwork?

    A look at an old ESP8266EX oh-so-brief DS shows 60uA for DEEP_SLEEP+RTC (probably true, some site measured a board at 77uA). I don’t trust the 10uA figure, it may be with the pin-wakeup option, but the data is presented ambiguously the usual way all these clowns write things when they don’t want to spell it out clearly. Also, as a sensor node, it will use 15mA in modem sleep mode (CPU on). So if you have a sensor widget that needs the CPU to be often on, it will eat into your power budget.

    But why bother, some of us would not entertain using ESP8266 as the primary MCU in the first place when one really needed low average power consumption. Even for real IoT projects (with high security reqs), you can get an Atmel SAM with AES etc and have it run under 2uA with RTC sleep.

    A thingy will run for 6 months _doing_nothing_ at 70uA with say a 300mAh Lipo. But if your average goes up to 1mA, you can run it for 12.5 days only. Jump in without power consumption data, and you will be at the mercy of battery sizing and hence, weight and dimensions.

    1. My bad, it’s ESP32, 5uA on RTC. I stand corrected, my apologies to Jarrett. It has AES etc too, nice. Their naming scheme sucks, ha ha.

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