Heltec T114 v2

Overview

Heltec Mesh Node T114 (Rev. 2.0) is an IoT development board designed and produced by Heltec Automation(TM). It combines an nRF52840 microcontroller with an SX1262 LoRa transceiver, optional 1.14” TFT display, and GNSS support. It is compatible with Meshtastic and LoRaWAN. See the Heltec Mesh Node T114 pages [1] for more details.

The features include the following:

  • Microprocessor: Nordic nRF52840 (ARM Cortex-M4F, 64 MHz, 256 KB RAM, 1 MB flash)

  • LoRa node chip: Semtech SX1262

  • Optional onboard 1.14” 135×240 TFT display (ST7789V, SPI)

  • GNSS module interface (NMEA over UART)

  • USB-C interface with USB device (CDC ACM) support

  • BLE 5.0, IEEE 802.15.4 (OpenThread)

  • One user button, one green LED, SK6812 RGB LED strip (2 LEDs)

  • Li-Po battery & solar panel 2*1.25mm connector

  • 2*13*2.54mm expansion pin headers

Supported Features

The heltec_t114_v2 board supports the hardware features listed below.

on-chip / on-board
Feature integrated in the SoC / present on the board.
2 / 2
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

See the Heltec Mesh Node T114 pages [1] for a complete list of board hardware features.

Connections and IOs

LED

  • LED4 (green) = P1.03

Push buttons

  • BUTTON0 = SW1 = P1.10

System Requirements

  • Host machine with USB port

  • USB-C cable for programming and serial console (CDC ACM)

  • Optional: J-Link or other SWD debugger for debugging

  • Optional: UF2 bootloader for drag-and-drop flashing; build with the heltec_t114_v2/nrf52840/uf2 board target

Programming and Debugging

The heltec_t114_v2 board supports the runners and associated west commands listed below.

flash debug

The default heltec_t114_v2/nrf52840 target uses the standard Nordic nRF52840 partition layout (full flash image, no Nordic nRF5 SDK bootloader / MBR link offset). Use the heltec_t114_v2/nrf52840/uf2 variant when building for the board’s UF2 bootloader and its application partition layout.

Applications for the heltec_t114_v2/nrf52840 board configuration can be built, flashed, and debugged in the usual way. See Building an Application and Run an Application for more details on building and running.

Flashing

First, run your favorite terminal program to listen for output (e.g. 115200 baud). Then build and flash. Example for the Blinky application:

west build -b heltec_t114_v2/nrf52840 samples/basic/blinky
west flash

For the UF2 bootloader variant (drag-and-drop firmware):

west build -b heltec_t114_v2/nrf52840/uf2 samples/basic/blinky
west flash

Debugging

Debugging is supported via SWD. Use an nRF52-compatible probe (e.g. nRF52840 DK, J-Link) and connect SWDIO, SWDCLK, GND, and VDD. Refer to the Nordic nRF5x Segger J-Link page to learn about debugging Nordic boards with a Segger IC. OpenOCD and Zephyr’s debug runner can also be used with the appropriate board configuration.

References