Heltec LoRa 32 V4 + Expansion Kit

⚠️ Check that radio.rxgain(on) and flood.advert.base (0.308) are set correctly after flashing! ⚠️

This build is based on official MeshCore 1.15.0 dev branch (as of 25-May-2026 and additionally includes the following unmerged upstream PRs/changes:

• PR2553: Limit flood advert packet forwarding --> set flood.advert.base 0...1 (0: no flood adv. forwarding, 0.308: default, 1: all flood adv. forwarding)
• PR1810: Allow direct message paths when denyf * is set
• :new: PR1727: Use hardware channel activity detection for checking interference --> Use set int.thresh 1 to activate hw based channel activity detection.
• :new: PR2377: Disable NRF52 undervoltage bootlock feature

Additional changes:

• Flood adverts are disabled (flood.advert.interval set to 0) by default
• :new: modified PR1810 to not block flood adverts but only PAYLOADTYPEGRPTXT and PAYLOADTYPEGRPDATA so that some limited flood advert distribution can be managed via PR2553 to support e.g. observer maps.

Changelog:

• Based on dev v1.15.0 as of 25-May-2026

Full Changelog: https://github.com/mattzzw/MeshCore-Evo/compare/v1.15.0-evo0.1.20...v1.15.0-evo0.1.21

Based on MeshCore v1.14.1 plus the below features:

16 April 2026 -v14.1.1: Disabled NRF52POWERMANAGEMENT for RAK4631, RAK3401, Heltec T114, Xiao NRF52, Senscap Solar and Ga56230s meshkit and Ga56230s mesh tracker pro. 10 Arpril 2026 - v14.1.1: [BETA] Added Power saving for Heltec v3, v4.2 and v4.3 companion BLE. Reduced from 120mA down to 32mA for Heltec v3 and 39mA for Heltec v4. LNA and FEM LNA use default settings (E.g On). 09 April 2026 - v14.1.1: Fixed reset issue in high traffic locations for ESP32-based repeaters and room servers.

NEW FEATURES:

Added Heltec v4.3 support: https://github.com/meshcore-dev/MeshCore/pull/1867. The PR will automatically detect Heltec v4.2 and v4.3. Added CLI control to LoRa's FEM LNA: https://github.com/meshcore-dev/MeshCore/pull/2140. Heltec T090 is not included. The details are below. Added CLI "powerlog" to list the last reset reason, last shutdown reason (NRF52 only) and last boot voltage (NRF52 only). This is to help debugging why the boards were reset due to software fault or low voltage (brownout).

FEM LNA vs. Chip LNA:
FEM LNA is external LNA from the 1W boards (such as Heltec v4.3). You can on / off this FEM LNA: set/get radio.fem.rxgain on/off. This will impact the RX gain and power consumption (up to 7.8mA). When this is off, Heltec v4.3 can reach 5.8mA. For Heltec v4.2, this CLI will return "Not supported" as it does not support FEM control.
Chip LNA inside SX1262: This is available to all boards including 1W boards. You can on/off this LNA : set/get radio.rxgain on/off. This will impact the RX gain and power consumption (up to 0.5mA)

Repeaters and Room Servers:

Included latest PowerSaving and PowerSaving CLI (powersaving, powersaving on and powersaving off): 5.0mA for NRF52, 10mA for Heltec v3, 13mA for Heltec v4.2 and 5.5 mA for Heltec v4.3 (with FEM off). https://github.com/meshcore-dev/MeshCore/pull/1687

#### Companions:
[NRF52] PowerSaving by default. Reduced from 9mA down to 5.8mA. https://github.com/meshcore-dev/MeshCore/pull/2286
[BETA] [ESP32] PowerSaving by default for Heltec v3 and v4. Reduced from 120mA down to 32mA for Heltec v3 and 39mA for Heltec v4.2 and 4.3.

Common features

Included sensor CLI to list I2C and UART GPIOs: sensor Kept date after crash/watchdog/brownout reset on ESP32: https://github.com/meshcore-dev/MeshCore/pull/1896 Automatically selected I2C address 0x76 and 0x77 for BME280/BME680/BMP280 Added i2c probe for sensors to start only in-use sensors: https://github.com/meshcore-dev/MeshCore/pull/1282 Added variant Xiao S3 (non-Wio) and Wio SX1262 (Initial support): SDA=D6, SCL=D7

Instruction:

Please upgrade your easy to access devices first. Download: Download upgrade.bin to upgrade existing devices or freshInstall-merged.bin for new devices. Instruction to Flash Custom Firmware. Please read the instruction in Add sensors to repeaters Source code for PowerSaving 14

Demo

Power Saving

Enter powersaving mode (CLI > powersaving on), 5.5mA for Heltec v4.3 with FEM and rxgain off, 5.8mA if FEM off and rxgain on. Thanks Wireless Rocks for your testing, . 13mA for Heltec v4.2 or Heltec V4.3 with FEM and rxgain on. 5.0mA for RAK4631

<img height="384" alt="image" src="https://github.com/user-attachments/assets/be6e298d-4931-4e83-8220-0d072f8aeefd" />
<img height="384" alt="image" src="https://github.com/user-attachments/assets/924aa3a5-64d0-4112-aa66-6ff72178d3ac" />
<img height="384" alt="image" src="https://github.com/user-attachments/assets/903d899d-66c4-4d88-bf61-e9601797009f" />

Default PowerSaving for Heltec v3, v4.2 and v4.3 companion BLE. Reduced from 120mA down to 32mA for Heltec v3 and 39mA for Heltec v4.
<img height="384" alt="image" src="https://github.com/user-attachments/assets/73689821-61cc-4c3e-833f-1511632b71df" />
<img height="384" alt="image" src="https://github.com/user-attachments/assets/f9161bf7-8a95-4e7d-b26a-7a6cbe88a615" />

PowerLog CLI

Enter CLI "powerlog" to see last reset/shutdown reason and the battery voltage during last boot. <img height="384" alt="image" src="https://github.com/user-attachments/assets/79a31bf6-a0c2-46d3-bf7e-d63ca27e3014" /> <img height="384" alt="image" src="https://github.com/user-attachments/assets/1870c4e7-5942-466e-af0c-66e7567c7aae" />

Sensor CLI

Enter CLI "sensor" to check I2C and GPS Serial pins <img height="384" alt="image" src="https://github.com/user-attachments/assets/060dd847-5984-4dc2-a5fe-cfe81180dc6c" /> <img height="384" alt="image" src="https://github.com/user-attachments/assets/49f25de7-a122-480f-a54a-a7176ec25f26" />

Support and Discussion

If you want us to compile for your boards or have question, please comment in GITHUB or DISCORD

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We can buy more test boards and test sensors for development. Enjoy MeshCore. 👯‍♂️

Full Changelog: https://github.com/MichTronics/MeshCoreNG/compare/bridge-tcp-v1.0.5...repeater-v1.0.1

Full Changelog: https://github.com/MichTronics/MeshCoreNG/compare/bridge-tcp-v1.0.5...companion-v1.0.1

Full Changelog: https://github.com/MichTronics/MeshCoreNG/compare/bridge-tcp-v1.0.5...companion-v1.0.1

Full Changelog: https://github.com/MichTronics/MeshCoreNG/compare/bridge-tcp-v1.0.5...room-server-v1.0.1