Power and energy measurement¶

PMU · INA · BATTERY · SOLAR

Six libraries deal with power: one for the power management chips on the T-Beam boards, four for current meters and one for a solar battery management system. They differ from the sensor group in that they do not only measure but also regulate.

[!NOTE] Source. This page was verified against the firmware itself: MeshCore v1.16.0, commit 03b6ef4, 28 July 2026 — files platformio.ini, src/helpers/esp32/TBeamBoard.h, src/helpers/esp32/TBeamBoard.cpp, src/helpers/sensors/EnvironmentSensorManager.cpp and variants/heltec_mesh_solar/platformio.ini.

How MeshCore calls this group¶

The four INA libraries follow the pattern from sensors.md: an ENV_INCLUDE_INA* flag, an init_ and a query_ function, a row in the sensor table. XPowersLib sits outside that: it belongs to the board layer, not the sensor layer, and is called when the board starts up.

src/helpers/esp32/TBeamBoard.cpp r.130

      PMU = new XPowersAXP2101(PMU_WIRE_PORT, PIN_BOARD_SDA1, PIN_BOARD_SCL1, I2C_PMU_ADD);

lewisxhe/XPowersLib¶

The T-Beam boards have a separate power management chip: the AXP192 on the older boards, the AXP2101 on the newer ones. Such a chip regulates the battery's charge current, switches the power rails to the radio and the GPS independently on and off, and measures the battery voltage. XPowersLib by Lewis He supports both chips behind one interface:

src/helpers/esp32/TBeamBoard.h r.87

#include "XPowersLib.h"

MeshCore keeps one XPowersLibInterface* and decides at start-up which chip sits behind it. Three variants use the library: lilygo_tbeam_SX1262, lilygo_tbeam_SX1276 and lilygo_tbeam_supreme_SX1262.

The four INA libraries¶

The INA chips from Texas Instruments measure current across a shunt resistor, and voltage alongside it. They differ in range, resolution and channel count.

adafruit/Adafruit INA219 — one channel, bus and shunt voltage readable separately, up to 26 V. In three variants. Its depends= asks for NeoPixel, GFX and SSD1306 for the example sketches; see ../dependencies.md.

robtillaart/INA226 — more accurate than the INA219, with configurable averaging over several measurements. In one variant, lilygo_tdeck.

adafruit/Adafruit INA260 Library — has the shunt resistor built in, so nothing needs calculating. In one variant, lilygo_tdeck.

adafruit/Adafruit INA3221 Library — three channels on one chip, with a sub_ch argument in the query_ function to say which channel is meant. In three variants.

meshsolar¶

For heltec_mesh_solar a zip of a full commit hash is fetched:

variants/heltec_mesh_solar/platformio.ini r.25

  https://github.com/NMIoT/meshsolar/archive/dfc5330dad443982e6cdd37a61d33fc7252f468b.zip

It provides the support for that board's battery management system, which balances a solar panel, a battery and the load against each other. Unlike a registry package, exactly which code you get is fixed here: the hash points at one commit.

Overview¶

Library	Version	Variants	Boards
`lewisxhe/XPowersLib`	`^0.2.7`	3	LilyGo T-Beam (AXP192, AXP2101)
`adafruit/Adafruit INA219`	`^1.2.3`	3	T-Deck, MinewSemi ME25LS01, ProMicro
`robtillaart/INA226`	`^0.6.4`	1	T-Deck
`adafruit/Adafruit INA260 Library`	`^1.5.3`	1	T-Deck
`adafruit/Adafruit INA3221 Library`	`^1.0.1`	3	T-Deck, MinewSemi ME25LS01, ProMicro
`NMIoT/meshsolar`	`dfc5330`	1	Heltec Mesh Solar

Sources¶

Translated from Dutch by Anthropic Claude