T-Beam V1.1 - Minimum current Draw

So I am trying to get the yaml file set up (BTW - is there an example of EVERY command that can be included in the yaml file???) for minimum current draw on the T-Beam V1.1 board. I have managed (with the enclosed yaml file) to reduce the current draw to an average of 51-53mA. I cannot seem to get some of the labels in power, position to be accepted. For example, I upload

meshtastic --port com7 --set power.lsSecs 444

and then do an export on the yaml file and it doesn’t “take”. I’ve tried ls_Secs as well…the manual doesn’t seem to match what is expected inside the unit.

I am still seeing the GPS LED flash every one second (the unit has been on for about 12 hours now). Shouldn’t the GPS be shut down except to get a daily fix on the satellites, record that then shut back down?

Any holes that you see in my yaml file please let me know. I have removed the appropriate info pertinent to our mesh network.

It is my belief that some of these commands within the yaml file are not being recognized by the T-Beam unit when I export the yaml file back out.



start of Meshtastic configure yaml

channel_url: REDACTED
enabled: true
fixedPin: 111111
serialEnabled: true
screenOnSecs: 60
region: US
hopLimit: 3
txEnabled: true
txPower: 30
ntpServer: 0.pool.ntp.org
gpsEnabled: true
fixed_position: true
gpsAttemptTime: 60
gpsUpdateInterval: 86400
positionBroadcastSmartEnabled: true
positionBroadcastSecs: 86400
positionFlags: 3
is_power_saving: true
lsSecs: 60
meshSdsTimeoutSecs: 7200
minWakeSecs: 10
sdsSecs: 2592000
waitBluetoothSecs: 60
deviceUpdateInterval: 900
environmentUpdateInterval: 900
owner: ABCDEFG
owner_short: ABCD

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The defaults are your best power choices for a tbeam, should last about 36 hours on a 3400mah battery.

But what are the defaults - how do i set it up (via the yaml) for repeater and such that the GPS turns off?

Is there a yaml that exists for each type of usage? If so, where are they located?

You can run meshtastic --export-config to see the defaults

You can read about all of the settings here Device Configuration | Meshtastic

There should be no need to update any of the power settings for a tbeam, the GPS does not turn off.

The problem with --export-config is that is doesn’t print out the default values only the values that I have changed, hence I cannot see what the ID names are (some don’t seem to match the online docs).

Using the docs or an app with an explanation of the settings is the way to go

So even if gps is “disabled” in the settings, that doesn’t actually shut it off?

Goes to sleep firmware/GPS.cpp at 20ee6a509dfb2c72693f49d1e0180a0bb9cc6b29 · meshtastic/firmware · GitHub

I am seeing no effect on the current draw with ANY command with the exception of the RF power output.

Also some Command(s) are not even changing values when sent a change via the command window or the yaml file.

When I set power.lsSecs to ANY value it always reverts back to 86400

Correct, there is no point trying to squeeze extra power saving by fiddling with those settings. The default for lsSecs is 300 so you have something weird going on there. I think I would do a factory reset and not change all those settings.

So are there any settings that will give me better current draw at all?

If you want lower power consumption get a nrf device, tbeam is already optimized.


I just wanted to chime in as someone who has tons of tbeams and wants to use them as solar nodes in some applications.

I do have to echo Garth that the tbeam is setup pretty much exactly how you want right out of the box. This doesn’t mean that there aren’t things you can do to keep your power usage at a minimum:

I would absolutely start with ensuring you only have the beam transmit when absolutely needed. Sending position updates every 15 probably isn’t needed. Turn off GPS and set fixed position. Maybe only sending a telemetry packet every hour is enough. Screen off is good too, it’s only using a few mA but every one counts. You can absolutely get more than 2 day of time out of a tbeam like this. This gets down low enough for me that some cheap oversized batteries and a good solar panel is enough. I certainly couldn’t handle Wi-Fi.

You should really look into RAK or other nrf based boards for your low power needs. They are literal orders of magnitude lower power.

Do you mind posting yr yaml file? My understanding is you cannot turn the GPS unit off.

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I can when I am back home; I don’t think the GPS can be turned off either.

I am mainly referring to reducing your overall position updates and how often you have the firmware do a GPS update. Not sure how much impact the latter has but for transmitting, you can see how that is the most power hungry action. – setting your unit as client_mute can also help as you will not be transmitting to rebroadcast to the mesh.

At the end of the day you certainly don’t want to be messing with things like sleep times and other power settings. The defaults are very well optimized for these boards. If you want more runtime, just grab some cheap 10,000mah lipos and replace the battery holder.

nRF is the way for low power. Fullstop.