Gauging interest in adding Meshtastic support for ESP32-S3 PowerFeather

[coral berry]

Hello everyone, I've been developing a board since last year. It's called ESP32-S3 PowerFeather, and it's a dev board with a focus on low power (specifically quiescent current during deep sleep) and extensive power management and monitoring.

I've designed it for solar-powered cellular applications in mind, but I was thinking this community might also be interested in it. From what I understand, there are generally two types of Meshtastic devices: portable/handheld devices and off-grid fixed-location nodes - the second one seems awfully similar to what I designed PowerFeather for.

Here are the features of PowerFeather which I think make it suitable for those applications (off-grid fixed deployments):

• up to 2 A charging
• thermistor input to reduce charge current/stop charging depending on battery temperature
• battery fuel gauge for charge estimation, voltage measurement, time-to-full/time-to-empty estimate, health&cycle count estimation, battery alarms
• I2C-controllable battery charger IC for getting supply/battery current, enable/disable charging, etc.
• firmware-settable MPP voltage to maximize power from solar panel, up to 16.8 V

(full features and other documentation at docs.powerfeather.dev)

There is no support for Meshtastic yet, and I was wondering if there is interest in me adding it.

[novel agate]

typical mesh nodes almost never enter the deep sleep state
Would your board also be advantageous for power usage during light sleep?

[coral berry]

The ESP32-S3 datasheet says that deep sleep is around 240 uA, and the board's quiescent current is maybe ~ 10 uA - so a little bit?
There are certainly ESP32-S3 dev boards that do a lot worse - like hundreds of microamps or even milliamps.
However, there are cheaper boards like the Firebeetle that also manages the same ~10 uA of quiescent current - albeit without
the power management and monitoring features the PowerFeather has.

[coral berry]

Since the release of ESP32-S3 PowerFeather last month I’ve been working on a demo web app that lets users explore some of the features of ESP32-S3 PowerFeather, which I recently got to a decent state:

The web app is served from the ESP32-S3 PowerFeather (acting as an AP) and is accessed from the tablet's web browser. The part encircled in yellow shows the battery being charged at 1.5 A from the solar panel at the set MPP voltage of around 12 V.

The web app also displays other supply & battery telemetry information as well as some power management controls which are all built-in into the board and accessed using the PowerFeather-SDK API.

For those interested in the demo web app, maybe to try it on their PowerFeather or just to see how this was created: https://github.com/PowerFeather/powerfeather-demo.

[limber laurel]

Meshtastic is designed as a chat application via Lora, whereby the routers and repeaters are as permanently accessible as possible. Typical receivers consume 10mA TX in continuous operation plus ~15mA RX plus MCU. This is why the nodes switch to light sleep as quickly as possible for reception.

[coral berry]

I actually looked over the Meshtastic code a few weeks ago , and from what I see light sleep is manually entered into - not using automatic light sleep features?

[limber laurel]

https://github.com/meshtastic/firmware/blob/2233507667c6030cc86d9e66a3746b2ed828d8ba/src/PowerFSM.cpp#L81

[coral berry]

I've made a showcase video for the ESP32-S3 PowerFeather: https://youtu.be/VF9AFk1Hf88

[coral berry]

Hi all, I've decided on trying out meshtastic on PowerFeather anyways, and it seems it is able to reach the theoretical light sleep current:

These are the configuration of this particular measurement:

• custom arduino-esp32 build enabling some PM stuff
• Router mode
• Bluetooth off
• No SX1262 attached (currently trying to isolate power usages one-by-one, made an SX1262 dummy interface to make the code happy) - from lurking in the channel, it seems RX mode is expected to be ~7 mA

I will be working on adding an SX1262 module next.

Hope this also answers your question @novel agate .