Heltec WiFi LoRa 32 V3

⚠️ 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

Down to 1mA with extra 50% less power consumption for coming winters

• Developed by IoTThinks and tested by our supportive MeshCore friends.
• Contribution to MeshCore: By IoTThinks%20is%3Apr%20author%3A%40IoTThinks).
• Source code: https://github.com/IoTThinks/MeshCore/tree/PowerSaving-v16

Credits

Mr. Dom4n: More details at Added RX duty-cycle power saving support PowerSaving friends: For comprehensive testings.

Notices:

[BETA] You are invited to test the GPS for RAK3401 and RAK12500 (I2C) and RAK12501 (L76K) For Xiao NRF52, there is 1 report of reducing range at 100km distance. We are investigating the issue. You may use powersaving on and set radio.rxps off.

Support Us

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Instruction:

• Scroll down to bottom to download uf2 / upgrade.bin to upgrade or freshInstall-merged.bin for new devices.
• Heltec v4 bin files is for both Heltec v4.2 and v4.3. Heltec v4.3 bin files is for Heltec v4.3 only
• Heltec v4.3 and T096 have two options FEM RXgain on and FEM Rxgain off.
• Flash Custom Firmware as in INSTRUCTION.
• If your board is not at the bottom section, please request us at GITHUB
• Fast support: Discord

PowerSaving Features

• Based on MeshCore 1.16

[NEW] RX PowerSaving

[NEW] RX PowerSaving (LoRa RX sleep) to keep power consumption of repeater down to 1mA. All other features would work as normal. [NEW] Better resistance to interferences from cell towers due to RX Sleep. During LoRa RX Sleep, LoRa will be waken up by preambles which are much likely from LoRa not other interferences. You may not need to do AGC reset set radio.agc.reset 4 any more. TODO: To set set radio.rxps balanced automatically when powersaving on

Essential CLIs:

powersaving on gps off set radio.fem.rxgain off (for Heltec v4.3 and T096 only) powersaving on => set radio.rxps balanced (Recommended) OR set radio.rxps level 10 preamble 16 (Maximum sleep for best compability) set radio.rxps level 10 preamble 32 (Maximum sleep for MeshCore 1.16 devices only)

All CLIs

Adds RX power-saving configuration:

• set radio.rxps off
• set radio.rxps on
• set radio.rxps conservative: This is level 1 preamble 16
• set radio.rxps balanced: this is level 5 preamble 16
• set radio.rxps <1-10> or set radio.rxps level <1-10>: From least RX PowerSaving to maximum RX PowerSaving. Preamble is either 16 (SF >8) or 32 (SF<=8)
• set radio.rxps level <1-10> preamble <16|32>: Preamble 32 will only work with devices from MeshCore 1.16 / PowerSaving 16.
• set radio.rxps <rxus> <sleepus>

Adds status and diagnostic commands:

• get radio.rxps
• get rxps.wd: To know if any error / reset of LoRa radio due to RX PowerSaving.

PowerSaving and GPS PowerSaving

LoRa will sleep during RX, wake up on coming preambles and proccess LoRa packets: PowerSaving: [Repeater] CLI powersaving on/off and powersaving. [BLE Companion] Enabled by default. GPS PowerSaving: [Repeater] CLI powersaving on, gps on and gps. [BLE Companion] Enabled by default when enabling Position in MeshCore app.

<img width="935" height="443" alt="image" src="https://github.com/user-attachments/assets/4e39bf13-08e7-4ea4-bbed-7b0b6856cd2e" />

Test Results

Test results are measured by Uni-T 890C 6000 counts: Heltec T096, 4.2 and 4.3 have external TX amplifier and comsume more power. In RX PowerSaving, the power current will fluctuate in the range. Estimated to save 30-50% of the power consumption compared to PowerSaving 16.

| Board | powersaving off<br/>set radio.rxps off | powersaving on<br/>set radio.rxps off | powersaving on <br/>set radio.rxps balanced | powersaving on <br/>set radio.rxps level 10 preamble 16 | Tested by |
| --- | --- | --- | --- | --- | --- |
| Heltec T096 repeater | 15.3mA | 9.1 mA | 4.6-8.8mA | 2.8-8.4mA | IoTThinks |
| Heltec T114 repeater | 14mA | 7.9mA | 3.4-7.5mA | 1.6-7.3mA | IoTThinks |
| Heltec v4.2 repeater<br/>(FEM always on) | 50mA | 14.5mA | 9.9-13.9mA | 8.0-13.4mA | IoTThinks |
| Heltec v4.3 repeater | - | - | - | - | IoTThinks |
| RAK4631 repeater | 8.8mA | 6.0mA | 2.4-5.8mA | 0.9-6.0mA | IoTThinks |
| ProMicro NRF52840 + SX1262 | 14mA | 7.9mA | 4.7-6.2mA | 2.6-4.7mA | user784213 |
| T-Echo Lite BLE companion | - | 9.6-13.4mA | 4.7-13.4mA | - | IoTThinks |
| T1000e BLE companion | - | 15-17mA via USB | 13-14mA via USB | - | IoTThinks |

RAK4631, T114, T096 repeaters
<img height="384" alt="image" src="https://github.com/user-attachments/assets/526ae136-79dc-44cd-ad0a-ea4a7baca805" />
<img height="384" alt="image" src="https://github.com/user-attachments/assets/834f39a7-b420-479f-ad19-14b93ebcdff0" />
<img height="384" alt="image" src="https://github.com/user-attachments/assets/a5a8246e-23a6-4a14-b251-e8631411b88b" />

Heltec v4.2 repeaters
<img height="384" alt="image" src="https://github.com/user-attachments/assets/15d12004-85db-4333-8e44-15746e6f1757" />

• Xiao NRF52 repeaters

<img width="2068" height="1166" alt="image" src="https://github.com/user-attachments/assets/6ffa3e5a-41b7-4642-a09c-b4fde64bcef7" /> <img width="2064" height="1166" alt="image" src="https://github.com/user-attachments/assets/c4733ef7-a940-403c-8955-34f48076c824" /> <img width="2064" height="1166" alt="image" src="https://github.com/user-attachments/assets/72887d5c-8e1c-4c8c-8911-4a96c0f979c3" />

Enjoy.

Keep making 1-2W solar repeaters and 5-day BLE companions possible:

• Developed by IoTThinks and tested by our supportive MeshCore friends.
• Contribution to MeshCore: By IoTThinks%20is%3Apr%20author%3A%40IoTThinks).
• Source code: https://github.com/IoTThinks/MeshCore/tree/PowerSaving-v16

IMPORTANT NOTICES

• For repeaters / room servers, after upgrade to PowerSaving 16, you need to check and set the default values again set flood.max 64 (default value) , set flood.max.unscoped 64 (default value) and set radio.fem.rxgain on/off (Heltec v4.3 and T096 only, if you set "off" before) https://github.com/meshcore-dev/MeshCore/pull/2140#issuecomment-4677295983

The power consumption of common boards is measured at battery cable. Ping us if your boards are not low power as expected. | Board | Repeaters / Room Servers | BLE Companions | Power Off for BLE Companions | | ------------- | ------------- | ------------- | ------------- | | Heltec v3 | 9mA | 19.6mA | ~16uA | | Heltec v4.2 and v4.3 (FEM ON) | 16mA | 28.6mA | ~16uA | | Heltec v4.3 (FEM Off) | 13mA | 24.9 mA | ~16uA | | Xiao S3, C3 | 7mA | 15 mA | ~16uA | | Xiao C6 | 7mA | C6 is not supported yet | ~16uA | | RAK 4631, Heltec T114, Xiao NRF52 | 5.8mA | 5.8mA | ~16uA | | Heltec T096 (FEM Off) | 8.7mA | 8.6 mA | ~16uA | | Heltec T096 (FEM On) | 16mA | 16 mA | ~16uA |

Support Us

Enjoying our work? Support us via  or .

Updates:

• v16.0.3: Fixed T-Echo lite to hibernate at 1mA instead 6mA. We will cut power more in PowerSaving 17 to reduce to 10uA.
• v16.0.2: Fixed GPS time sync for Heltec T114. It will sync after boot and GPS lock. It will sync time every 30 minutes or by manual "gps sync"
• v16.0.1: Wio Tracker L1 BLE companion has high power consumption is at 35mA in PowerSaving 16 instead of 7.5mA as in PowerSaving 15. This issue might affect a few NRF52 boards with GPS modules attached.

Instruction:

• Scroll down to bottom to download uf2 / upgrade.bin to upgrade or freshInstall-merged.bin for new devices.
• Heltec v4 bin files is for both Heltec v4.2 and v4.3. Heltec v4.3 bin files is for Heltec v4.3 only
• Heltec v4.3 and T096 have two options FEM RXgain on and FEM Rxgain off.
• Flash Custom Firmware as in INSTRUCTION.
• If your board is not at the bottom section, please request us at GITHUB
• Fast support: Discord

Features:

Based on MeshCore 1.16, plus PowerSaving features and more:

• Repeaters and room servers for both ESP32 and NRF52: CLI powersaving on, powersaving off and powersaving
• BLE companions for both ESP32 and NRF52: Enabled by default
• [NEW] Hibernate mode for ESP32 BLE Companions now work properly and at 16uA
• [NEW] Optimize Heltec T096 from 12mA down to 8.7mA
• [NEW] Repeaters for both ESP32 and NRF52: CLI set reboot.interval <hours> and get reboot.interval. hours is 0-255. 0 is default and disabled. This helps to recover repeaters due to unknown hang.
• [NEW] Set return path for repeaters: https://github.com/meshcore-dev/MeshCore/pull/2586
• [NEW] Add time keeping for NRF52 across resets: https://github.com/meshcore-dev/MeshCore/pull/2704
• FEM LNA for Heltec v4.3, Heltec T096, Heltec TrackerV2: CLI set radio.fem.rxgain on/off and get radio.fem.rxgain. https://github.com/meshcore-dev/MeshCore/pull/2140
• Automatically select I2C address (0x76 or 0x77) for BME280, BME680 and BMP680.
• Fixed boot loop for Xiao C6: https://github.com/meshcore-dev/MeshCore/pull/2570
• Check reset reasons for repeaters: CLI powerlog
• Check I2C and GPS GPIOs: for repeaters: CLI sensor

Hot fixes:

• For BLE companions, possible hang after a while due to CMDSENDRAW_PACKET errors accumulate memory:

https://github.com/meshcore-dev/MeshCore/issues/2721. Fixed: https://github.com/meshcore-dev/MeshCore/pull/2722

Demo

Power Saving for Hibernate mode in BLE Companion

Heltec v4.2 Companion can enter Hibernate mode at 16.4uA <img height="512" alt="image" src="https://github.com/user-attachments/assets/08c5c0d6-9960-4cb4-bcaf-a1d2d1ba78a0" />

Power Saving for repeaters

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. 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" />

Power Saving for BLE companions

Default PowerSaving for ESP32 companion BLE. Reduced from 120mA down to 15-25mA. <img height="384" alt="image" src="https://github.com/user-attachments/assets/bcae8449-4646-4a98-852f-312582686ad6" /> <img height="384" alt="image" src="https://github.com/user-attachments/assets/2fc5bee1-fe89-4c8f-8097-2db181d89f4a" /> <img height="384" alt="image" src="https://github.com/user-attachments/assets/656fcd90-3211-4044-832b-a63f30c2fb4a" /> <img height="384" alt="image" src="https://github.com/user-attachments/assets/7611ebb5-d2d1-42b7-8845-6016e838b0cf" />

PowerLog and Sensor CLI

Enter CLI "powerlog" to see last reset/shutdown reason and the battery voltage during last boot. Enter CLI "sensor" to check I2C and GPS Serial pins <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" /> <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" />

Enjoy the long battery life. 👯‍♂️ 👯‍♂️ 👯‍♂️

v1.16_0607

• Companion UI: Native multilingual display on Heltec T096 (ST7735S)

Node names and messages now render natively on the T096 color TFT — characters are displayed as-is instead of being converted to ASCII equivalents. Supported languages include all 31 from v1.14 plus additional scripts:

Latin-based: Catalan, Croatian, Czech, Danish, Dutch, Estonian, Finnish, French, German, Hungarian, Icelandic, Italian, Latvian, Lithuanian, Maltese, Norwegian, Polish, Portuguese, Romanian, Slovak, Slovenian, Spanish, Swedish, Turkish, Vietnamese, Welsh

Cyrillic: Belarusian, Bulgarian, Macedonian, Russian, Serbian, Ukrainian

Greek: Greek

• Companion UI: Contacts screen now includes room servers; request telemetry from any contact.

Room servers appear in the contact list tagged [R]. Selecting any contact — chat node or room server — and long pressing opens an action menu: Send message or Request telemetry. Requesting telemetry displays the node's battery voltage and GPS coordinates (if present); long press to open the GPS Trace screen for that location.

GPS coordinates follow the Pos. Format selected in Settings (DD, UTM, or MGRS).

The message inbox group list now tags group/channel entries with [G] and room server entries with [R] for consistent visual distinction. Each room message shows the original author's name. When viewing a room message, long press to open the popup and select Reply to post back to the room (visible to all subscribers).

> Private room servers: messaging requires a prior login. Public rooms (no password) work without any login. For private rooms, log in once via the MeshCore app — if your account has admin rights on that room server, the session persists across reboots. Regular user sessions are not saved to flash and will require re-login after the room server reboots.

• Companion: switch the app connection between BLE and USB serial without reflashing.

In USB mode the node behaves like a standard usb build — the PC app connects over the USB serial port directly. Toggle via Settings → Connection Mode on the display, or via TerminalCLI: set conn.mode usb / set conn.mode ble. The setting persists across reboots. BLE toggle is hidden in the Settings menu while USB mode is active.

• Repeater, Room Sever: hold user button 5 seconds to power off.

Hold the user button for 5 seconds to power off the node — faster than reaching for the CLI when you're standing next to it. The LED blinks 5 times as a warning before shutdown.

• Repeater, Room Server: advert.hops.max default changed to 8; room server support added; flood.max.advert alias.

advert.hops.max now defaults to 8 instead of flood.max — advert relay limiting is active out of the box without any configuration. Room servers now also enforce this limit (previously repeater-only). The command flood.max.advert is accepted as an alias for compatibility with upstream firmware.

v1.160802

• New: standby mode and GNSS mode selection for a confirmed ATGM336H-6N quick-link GPS module. (Companion, Repeater, Room Server — E213, V3, E290)

Both take effect only once the attached module is confirmed to be an ATGM336H-6N — detected from the module's own hardware-info reply (tested via M5Stack's Unit GPS v1.1); other modules are left alone.

• Standby mode: the quick-link GPS module is externally, continuously powered — the board has no wire to cut its power directly. Turning GPS off (or between fixes, while duty-cycling) now sends the module into its own low-power standby mode instead of leaving it running at full power the whole time.
• GNSS mode selection: the same GNSS Mode setting already available on V4 and T096 (CLI get/set gps.mode, Companion Portal dropdown, shown read-only on the on-device GPS page) is now available on E213, V3, and E290 too: GPS / GPS+BDS / GPS+BDS+GLONASS+Galileo / GPS+BDS+GLONASS+Galileo+QZSS.

• New: GPS-on reminder icon in the header. (Companion — all platforms with GPS)

GPS is easy to turn on and forget about, quietly draining the battery in the background. A small circle-with-center-dot icon now appears in the header whenever GPS is active, positioned just left of the battery icon. Shown on the Home page only on OLED (limited header space); shown on every page on T096 and e-ink, which have more header room.

• New: gps.minsat / gps.hdop — tune how many satellites and how accurate a fix needs to be before GPS reports it as valid. (Companion, Repeater, Room Server — all platforms with GPS)

Previously fixed in firmware (minimum 6 satellites, HDOP ≤ 2.0). Now configurable via CLI (get/set gps.minsat, get/set gps.hdop) and the Companion/Repeater/Room Server portal, so it can be tuned for different sky conditions without a rebuild. Companion's GPS page also now shows current HDOP next to satellite count (sat / hdop).

> Heltec V3 GPS wiring: module RX → GPIO47, module TX → GPIO48.
> Heltec E213 GPS wiring: module RX → GPIO43, module TX → GPIO44.
> Heltec E290 GPS wiring: module RX → GPIO43, module TX → GPIO44.

• New: configurable default channel for Quick Send. (Companion — all platforms)

Quick Send previously always sent to the Public channel. It now targets a configurable channel instead, settable via Qk.Ch. in on-device Settings, CLI (get/set quick.channel), or a new Default Channel dropdown in the Companion Portal's Quick Send Presets section — and included in portal backup/restore.

Heltec T096 antennas wear out easily with just light usage.
<img width="3024" height="2268" alt="IMG7070" src="https://github.com/user-attachments/assets/91f685f3-98af-4bcd-b60a-7136c545ca1a" />

v1.160802

• New: standby mode and GNSS mode selection for a confirmed ATGM336H-6N quick-link GPS module. (Companion, Repeater, Room Server — E213, V3, E290)

Both take effect only once the attached module is confirmed to be an ATGM336H-6N — detected from the module's own hardware-info reply (tested via M5Stack's Unit GPS v1.1); other modules are left alone.

• Standby mode: the quick-link GPS module is externally, continuously powered — the board has no wire to cut its power directly. Turning GPS off (or between fixes, while duty-cycling) now sends the module into its own low-power standby mode instead of leaving it running at full power the whole time.
• GNSS mode selection: the same GNSS Mode setting already available on V4 and T096 (CLI get/set gps.mode, Companion Portal dropdown, shown read-only on the on-device GPS page) is now available on E213, V3, and E290 too: GPS / GPS+BDS / GPS+BDS+GLONASS+Galileo / GPS+BDS+GLONASS+Galileo+QZSS.

• New: GPS-on reminder icon in the header. (Companion — all platforms with GPS)

GPS is easy to turn on and forget about, quietly draining the battery in the background. A small circle-with-center-dot icon now appears in the header whenever GPS is active, positioned just left of the battery icon. Shown on the Home page only on OLED (limited header space); shown on every page on T096 and e-ink, which have more header room.

• New: gps.minsat / gps.hdop — tune how many satellites and how accurate a fix needs to be before GPS reports it as valid. (Companion, Repeater, Room Server — all platforms with GPS)

Previously fixed in firmware (minimum 6 satellites, HDOP ≤ 2.0). Now configurable via CLI (get/set gps.minsat, get/set gps.hdop) and the Companion/Repeater/Room Server portal, so it can be tuned for different sky conditions without a rebuild. Companion's GPS page also now shows current HDOP next to satellite count (sat / hdop).

> Heltec V3 GPS wiring: module RX → GPIO47, module TX → GPIO48.
> Heltec E213 GPS wiring: module RX → GPIO43, module TX → GPIO44.
> Heltec E290 GPS wiring: module RX → GPIO43, module TX → GPIO44.

• New: configurable default channel for Quick Send. (Companion — all platforms)

Quick Send previously always sent to the Public channel. It now targets a configurable channel instead, settable via Qk.Ch. in on-device Settings, CLI (get/set quick.channel), or a new Default Channel dropdown in the Companion Portal's Quick Send Presets section — and included in portal backup/restore.

Heltec T096 antennas wear out easily with just light usage.
<img width="3024" height="2268" alt="IMG7070" src="https://github.com/user-attachments/assets/91f685f3-98af-4bcd-b60a-7136c545ca1a" />

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