NeonPocketMC ULP Solar Repeaters

Experimental, low-power MeshCore repeaters for solar and battery deployments.

This firmware is built from IoTThinks' PowerSaving-v17 MeshCore fork, with the power-saving work fully attributed in docs/EASYSKYMESH_ATTRIBUTION.md. It tracks MeshCore 1.17.1 and adds NeonPocketMC hardware profiles, default-on setup, a simpler ulp command, TFT support for RCC6/RC52, packaging, and a guided USB configurator.

Experimental. RX duty cycling saves power by intentionally spending part of each interval asleep. A ULP repeater can miss packets that a continuously listening repeater would receive. Test coverage and current draw at the actual deployment site before relying on it.

Builds

Release build	Hardware	Display
Heltec V3	WiFi LoRa 32 V3 / SX1262	Built-in OLED
Heltec V4	WiFi LoRa 32 V4 / SX1262	Built-in OLED
RAK4631	WisBlock Core RAK4631 / SX1262	Optional SSD1306
RAK3401 1W	RAK3401 + RAK13302/SKY66122	Optional SSD1306
Xiao ESP32-S3	Seeed Xiao ESP32-S3 + supported SX1262 wiring	Headless
Xiao nRF52840	Seeed Xiao nRF52840 + supported SX1262 wiring	Headless / null display
RCC6 Headless	Heltec RadioCore RCC6-L62	TFT held off
RCC6 TFT	RCC6-L62 + NV3001B 220×128	Indexed framebuffer; auto-off
RC52 Headless	Heltec RadioCore RC52-L62	TFT held off
RC52 TFT	RC52-L62 + NV3001B 220×128	Indexed framebuffer; auto-off

Hardware warning: these boards do not all accept an unregulated solar panel. Use a protected battery and an external MPPT/solar charge controller matched to the panel and cell. Never connect a raw panel directly to VBAT or USB.

Default power behavior

For a new installation, power saving is ON by default:

• MCU light sleep is enabled after the existing two-minute startup window on ESP32 and whenever idle on nRF52.
• SX1262 radio RX duty cycling starts in the balanced profile: level 5, preamble 16.
• GPS duty scheduling is automatic when a supported GPS is explicitly enabled; this firmware does not turn GPS on by default.
• TFT/OLED builds turn the display off after inactivity; LoRa continues operating.
• If radio duty-cycle arming fails, the IoTThinks implementation falls back to continuous receive and limits retries rather than leaving the radio deaf.

Saved preferences always win after an upgrade. A previously configured device is not silently forced back to balanced mode.

Easy setup

1. Flash the build matching the exact board.
2. Keep USB and the antenna connected.
3. Download the release's NeonPocketMC-ULP-Configurator.zip.
4. Windows: double-click configure-ulp-windows.bat.
5. Linux: run sh configure-ulp-linux.sh.
6. Pick the serial device, region, name, transmit power, map-location policy, admin password, and ULP profile.

The wizard verifies that it is talking to NeonPocket ULP firmware before changing anything.

ULP builds configure over USB and do not create a Wi-Fi access point or WebUI. Keep USB connected until the wizard reports success. If location sharing is enabled, the wizard explicitly sets gps advert prefs; choosing no sets gps advert none. A TFT may show BAT: -- on USB when RCC6 cannot produce a physically valid single-cell reading rather than displaying a false voltage.

Simple manual CLI

Open the USB serial port at 115200 baud and end each command with Enter/CR:

ulp
ulp on
ulp conservative
ulp max
ulp off

• ulp or ulp status: show MCU and radio state.
• ulp on / ulp balanced: recommended balanced profile.
• ulp conservative: more receive time, smaller savings.
• ulp max: highest duty cycling; may not hear older pre-1.16 transmitters.
• ulp off: continuous radio RX and no MCU sleep.

Advanced EasySkyMesh-compatible controls remain available through get radio.rxps, set radio.rxps ..., and powersaving ....

Installation

ESP32 boards: V3, V4, Xiao ESP32-S3, RCC6

• Normal update: flash the *-app.bin at address 0x10000.
• Recovery only: flash *-full-recovery.bin at 0x0.
• The full image includes the bootloader, partition table, and app. It does not deliberately erase the separate MeshCore filesystem, but normal app-only flashing is the identity-preserving path.
• Never flash an image for another board.

nRF52 boards: RAK4631, RAK3401 1W, Xiao nRF52840, RC52

• Enter the board's UF2 bootloader and copy the exact .uf2 for that board.
• This is an application image; do not erase or replace the SoftDevice/bootloader.
• .hex is provided for advanced recovery tools.

See docs/INSTALL.md for board-specific notes and docs/POWER_SAVING.md for the tradeoffs.

Source and reproducibility

• NeonPocket ULP base: IoTThinks/MeshCore PowerSaving-v17 commit a3b9ad91a5bf04e7e00713595469dc868de53628.
• MeshCore upstream base: 1.17.1 commit d92964352441e53b93e8667b802e04f6e072b39e.
• EasySkyMesh reference release: PowerSaving17.1.
• All ten release environments are built by GitHub Actions and shipped with SHA-256 manifests.

This community project is not an official Heltec, RAKwireless, Seeed Studio, MeshCore, or EasySkyMesh release.

License

MIT, retaining all upstream notices. See license.txt and docs/EASYSKYMESH_ATTRIBUTION.md.