MeshCore-RelayRadio/AGENTS.md

Project: MeshCore Relay Radio (for opencode)

Goal

Modify MeshCore companion_radio firmware for Heltec T114 to control a relay and read DS18B20 temperature sensor via LoRa mesh private messages.

Hardware

• Board: Heltec T114 (nRF52840 + SX1262)
• Relay: GPIO 4 (RELAY_PIN)
• DS18B20: GPIO 5 (ONE_WIRE_BUS) with 4.7k pull-up
• BLE PIN (for BLE variant): 123456

Radio Parameters

• Frequency: 868.731018 MHz
• Bandwidth: 62.5 kHz
• Spreading Factor: 7
• Coding Rate: 7
• Path Hash: 1 byte (mode 0)

Commands (via private mesh messages)

Command	Response	Action
on1234	relay on	Relay ON
off1234	relay off	Relay OFF
temp	temp: 23.5 C	Read DS18B20 temp
state	temp: 23.5 C, relay: ON	Temp + relay state

Numbers in commands (e.g. 1234) are a PIN code, not validated by firmware.

Source Files

Modified files (relative to MeshCore root):

• examples/relay_radio/MyMesh.h — class declaration, relay/temp fields
• examples/relay_radio/MyMesh.cpp — relay on/off logic, temp reading, command parsing
• examples/relay_radio/main.cpp — entry point, BLE config, pin setup
• platformio.ini — added OneWire/DallasTemperature libs, 2 new envs for T114

Build Environments

Two envs defined in platformio.ini:

1. Heltec_t114_relay_radio_usb — Serial USB interface
2. Heltec_t114_relay_radio_ble — BLE interface with PIN 123456

Both based on existing Heltec_t114 variant.

Build & Flash

# Build
pio run -e Heltec_t114_relay_radio_usb
pio run -e Heltec_t114_relay_radio_ble

# Flash
pio run -e Heltec_t114_relay_radio_ble -t upload --upload-port <port>

UF2 Drag-and-Drop

1. Double-tap reset button on T114 to enter UF2 mode
2. Copy firmware.uf2 from .pio/build/Heltec_t114_relay_radio_ble/ to mounted disk

Key Implementation Details

• Commands received via onMessageRecv() callback
• Response sent via sendMessage() (reuses encrypted chat channel)
• Timer-based advert in MyMesh::loop() every 30 min (1800000 ms)
• OneWire/DallasTemperature initialized in constructor
• Temperature read on demand (not periodically)
• All parameters settable via build flags in platformio.ini

Auto-Advert Timing

• Interval: 30 minutes (1800000 ms)
• Advert name: "Relay" (set via ADVERT_NAME define)
• Implemented in MyMesh::loop() with _next_advert_ms field

Repository

• Gitea: https://git2.ua1zbe.ru/ua1zbe/MeshCore-RelayRadio
• Release v1.0.0 with UF2 binaries (BLE + USB)
• User credentials: ua1zbe / Personal Access Token: 067f4415552ac62ba4ff8e7704c924da17dd3fbf

Updating Gitea

cd /tmp/opencode/fresh-repo
git add -A
git commit -m "message"
git push origin main

Creating a New Release

TOKEN="067f4415552ac62ba4ff8e7704c924da17dd3fbf"
VERSION="v1.1.0"

# Tag and push
git tag -a "$VERSION" -m "Release $VERSION"
git push origin "$VERSION"

# Create release
curl -s -X POST "https://git2.ua1zbe.ru/api/v1/repos/ua1zbe/MeshCore-RelayRadio/releases" \
  -H "Content-Type: application/json" \
  -H "Authorization: token $TOKEN" \
  -d "{\"tag_name\":\"$VERSION\",\"name\":\"$VERSION\",\"body\":\"Release description\"}"

# Upload assets (get RELEASE_ID from response)
curl -s -X POST "https://git2.ua1zbe.ru/api/v1/repos/ua1zbe/MeshCore-RelayRadio/releases/$RELEASE_ID/assets" \
  -H "Authorization: token $TOKEN" \
  -F "attachment=@path/to/file.uf2" \
  -F "name=Heltec_T114_BLE_firmware.uf2"

Ongoing Maintenance

• Firmware is based on upstream MeshCore. To update, re-clone MeshCore, re-apply the examples/relay_radio/ modifications, and rebuild.
• The relay_radio example lives in examples/relay_radio/ — it is a modified copy of examples/companion_radio/.
• Compiled UF2 files are kept in /home/ua1zbe/Рабочий стол/relay_radio_firmware/ on the developer machine.
• Full build/usage instructions: README.md