Heltec Wireless Paper

⚠️ 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.

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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. 👯‍♂️ 👯‍♂️ 👯‍♂️

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