LilyGO T-Beam v1.1/v1.2 (SX1276 or SX1262)
18650 holder, AXP192/AXP2101 power management, u-blox GPS, 0.96" OLED, no SD card slot. The transceiver and the PMU revision are both detected at boot. Serial is a CH9102 bridge — hold the middle button while pressing RST if flashing does not start. The serial port also carries PPP: pppd on the host makes the node a network interface at 10.65.<n>.1 (docs/local-link.md).
01 Hardware
| Vendor | LilyGO |
| PlatformIO env | tbeam |
| Board header | src/boards/tbeam.h |
| MCU | ESP32: 4 MB flash, 4 MB PSRAM |
| Chip family | ESP32 |
| Radio | SX1276 (v1.1) or SX1262 (v1.2) — detected at boot |
| Display | 0.96" SSD1306 (I²C) |
| Extras | 18650 holder, AXP192/AXP2101 PMU, u-blox GPS, PPP over the CH9102 bridge; no SD slot |
| Host links | Wi-Fi access point + station · CH9102 serial bridge · PPP over that bridge |
| Flashing | esptool can reset the chip through this port |
02 Radio
| Transceiver | SX1276/78 or SX1262 — detected at boot |
| Radio family | SX126x / SX127x |
| As the registry states it | SX1276 (v1.1) or SX1262 (v1.2) — detected at boot |
| Default channel | 869.525 MHz · BW 125 kHz · SF8 · CR 4/5 · 7 dBm inherited from Config.h |
| SPI bus | VSPI |
Every node on a channel must agree on frequency, bandwidth, spreading factor,
coding rate and sync word. These are the defaults this build ships with; they are changed
live on the node's settings page, which prints the matching RNodeInterface block.
03 Pin map
Read straight out of src/boards/tbeam.h — every peripheral
the firmware drives on this board, and the GPIO it drives it on. A harness diagram, not a
picture of where the parts sit.
Every pin as a table, with the define it comes from
| Peripheral | Signal | GPIO | Define | Note |
|---|---|---|---|---|
| Radio | SCK | GPIO 5 | PIN_LORA_SCK | |
| MISO | GPIO 19 | PIN_LORA_MISO | ||
| MOSI | GPIO 27 | PIN_LORA_MOSI | ||
| CS | GPIO 18 | PIN_LORA_CS | ||
| RST | GPIO 23 | PIN_LORA_RST | ||
| BUSY | GPIO 32 | PIN_LORA_BUSY | ||
| DIO1 | GPIO 33 | PIN_LORA_DIO1 | ||
| DIO0 | GPIO 26 | PIN_LORA_DIO0 | ||
| OLED panel | SDA | GPIO 21 | PIN_OLED_SDA | |
| SCL | GPIO 22 | PIN_OLED_SCL | ||
| GNSS | RX | GPIO 34 | PIN_GPS_RX | |
| TX | GPIO 12 | PIN_GPS_TX | ||
| Power management | SDA | GPIO 21 | PIN_PMU_SDA | |
| SCL | GPIO 22 | PIN_PMU_SCL | ||
| IRQ | GPIO 35 | PIN_PMU_IRQ | ||
| Controls & indicators | BTN | GPIO 38 | PIN_BUTTON |
04 Firmware support
What this build actually drives on this board. Where a part is fitted but left alone, the firmware's own reason is quoted underneath rather than summarised.
| Capability | State | Detail |
|---|---|---|
| Reticulum transport | driven | Path table, announce propagation, hop-by-hop forwarding |
| Wi-Fi AP + captive portal | driven | Status page, neighbours, bulletin board, settings |
| TCP 4242 + AutoInterface | driven | Stock RNS clients, zero-config discovery |
| LoRa radio | driven | SX1276/78 or SX1262 — detected at boot Shared SPI bus; the transceiver-specific lines are both defined so the SX127x and SX1262 probes each find what they need |
| Radio self-test at boot | no | Proves the IRQ line on first boot |
| RF front end | no | Driven before the radio can hear anything |
| External PA | no | — |
| Display | driven | OLED · 128×64 |
| Backlight control | no | — |
| Touch layer | no | — |
| Keyboard | no | On its own microcontroller, over I²C |
| Trackball | no | — |
| microSD | no | Reticulum store moves onto the card when one is present |
| GNSS | driven | 9600 baud u-blox NEO-6M/NEO-8M on UART1. Present but left unpowered by default — nothing uses it yet and it costs tens of milliamps |
| Real-time clock | no | Seeds the system clock at boot |
| Power management IC | driven | — The PMU shares the OLED's I2C bus and reports battery voltage itself, so there is no ADC divider to read |
| Battery gauge | no | — |
| IMU | no | — |
| Magnetometer | no | — |
| Environment sensor | no | — |
| Sounder | no | — |
| USB networking (CDC-NCM) | no | The node is an Ethernet link with DHCP over the cable |
| PPP over the serial bridge | driven | Bridge: CH9102 |
05 Bench notes
verified on hardware — see the T-Beam notes below; PPP built, not yet run on this board.
06 Install
Browser
Pick LilyGO T-Beam v1.1/v1.2 (SX1276 or SX1262) in the web flasher and click Install. Desktop Chrome or Edge, over HTTPS.
Terminal
pipx run --spec "git+https://github.com/dobrevit/RetiMesh_Node#subdirectory=tools/retimesh-flash" \ retimesh-flash install --board tbeam
From source
pio run -e tbeam pio run -e tbeam -t upload pio run -e tbeam -t uploadfs