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.

heltec_t114_v2/nrf52840 target

Type

Location

Description

Compatible

CPU

on-chip

ARM Cortex-M4F CPU1

arm,cortex-m4f

ADC

on-chip

Nordic Semiconductor nRF family SAADC node1

nordic,nrf-saadc

ARM architecture

on-chip

Nordic UICR (User Information Configuration Registers)1

nordic,nrf-uicr

on-chip

Nordic EGU (Event Generator Unit)6

nordic,nrf-egu

on-chip

Nordic nRF family ACL (Access Control List)1

nordic,nrf-acl

on-chip

Nordic nRF family MWU (Memory Watch Unit)1

nordic,nrf-mwu

Audio

on-chip

Nordic PDM (Pulse Density Modulation interface)1

nordic,nrf-pdm

Clock control

on-chip

Nordic nRF clock control node1

nordic,nrf-clock

on-chip

Nordic nRF high-frequency crystal oscillator (nRF52 series)1

nordic,nrf52-hfxo

Comparator

on-chip

Nordic nRF COMP (analog COMParator)1

nordic,nrf-comp

Counter

on-chip

Nordic nRF timer node5

nordic,nrf-timer

Cryptographic accelerator

on-chip

Nordic ECB (AES electronic codebook mode encryption)1

nordic,nrf-ecb

on-chip

Nordic nRF family CCM (AES CCM mode encryption)1

nordic,nrf-ccm

on-chip

ARM TrustZone CryptoCell 3101

arm,cryptocell-310

Debug

on-chip

ARMv7 instrumentation trace macrocell1

arm,armv7m-itm

Display

on-board

Sitronix ST7789V display controller1

sitronix,st7789v

Flash controller

on-chip

Nordic NVMC (Non-Volatile Memory Controller)1

nordic,nrf52-flash-controller

on-chip

Properties defining the interface for the Nordic QSPI peripheral1

nordic,nrf-qspi

GNSS

on-board

Generic GNSS NMEA receiver1

gnss-nmea-generic

GPIO & Headers

on-chip

NRF5 GPIOTE1

nordic,nrf-gpiote

on-chip

NRF5 GPIO2

nordic,nrf-gpio

I2C

on-chip

Nordic nRF family TWIM (TWI master with EasyDMA)2

nordic,nrf-twim

I2S

on-chip

Nordic I2S (Inter-IC sound interface)1

nordic,nrf-i2s

IEEE 802.15.4

on-chip

Nordic nRF IEEE 802.15.4 node1

nordic,nrf-ieee802154

Input

on-board

Group of GPIO-bound input keys1

gpio-keys

Interrupt controller

on-chip

ARMv7-M NVIC (Nested Vectored Interrupt Controller)1

arm,v7m-nvic

LED

on-board

Group of GPIO-controlled LEDs1

gpio-leds

LED strip

on-board

Worldsemi WS2812 LED strip, GPIO binding1

worldsemi,ws2812-gpio

LoRa

on-board

Semtech SX1262 LoRa Modem1

semtech,sx1262

Miscellaneous

on-chip

Nordic FICR (Factory Information Configuration Registers)1

nordic,nrf-ficr

on-chip

Nordic nRF family PPI (Programmable Peripheral Interconnect)1

nordic,nrf-ppi

MTD

on-chip

Flash node1

soc-nv-flash

Networking

on-chip

Nordic nRF family RADIO peripheral1

nordic,nrf-radio

on-chip

Nordic nRF family NFCT (Near Field Communication Tag)1

nordic,nrf-nfct

Pin control

on-chip

Nordic nRF family Pin Controller1

nordic,nrf-pinctrl

Power management

on-chip

Nordic nRF power control node1

nordic,nrf-power

PWM

on-chip

nRF PWM4

nordic,nrf-pwm

on-chip

nRFx S/W PWM1

nordic,nrf-sw-pwm

Regulator

on-chip

Nordic nRF5X regulator (fixed stage of the core supply)1

nordic,nrf5x-regulator

on-chip

Nordic nRF52X regulator (high voltage stage of the main supply)1

nordic,nrf52x-regulator-hv

Retained memory

on-chip

Nordic GPREGRET (General Purpose Register Retention) device2

nordic,nrf-gpregret

RNG

on-chip

Nordic nRF family RNG (Random Number Generator)1

nordic,nrf-rng

RTC

on-chip

Nordic nRF RTC (Real-Time Counter)3

nordic,nrf-rtc

Sensors

on-chip

Nordic nRF family TEMP node1

nordic,nrf-temp

on-chip

Nordic nRF quadrature decoder (QDEC) node1

nordic,nrf-qdec

Serial controller

on-chip

Nordic nRF family UARTE (UART with EasyDMA)11

nordic,nrf-uarte

SPI

on-chip

Nordic nRF family SPIM (SPI master with EasyDMA)12

nordic,nrf-spim

on-chip

Nordic nRF family SPI (SPI master)1

nordic,nrf-spi

SRAM

on-chip

Generic on-chip SRAM1

mmio-sram

Timer

on-chip

ARMv7-M System Tick1

arm,armv7m-systick

USB

on-chip

Nordic nRF52 USB device controller1

nordic,nrf-usbd

Watchdog

on-chip

Nordic nRF family WDT (Watchdog Timer)1

nordic,nrf-wdt

heltec_t114_v2/nrf52840/uf2 target

Type

Location

Description

Compatible

CPU

on-chip

ARM Cortex-M4F CPU1

arm,cortex-m4f

ADC

on-chip

Nordic Semiconductor nRF family SAADC node1

nordic,nrf-saadc

ARM architecture

on-chip

Nordic UICR (User Information Configuration Registers)1

nordic,nrf-uicr

on-chip

Nordic EGU (Event Generator Unit)6

nordic,nrf-egu

on-chip

Nordic nRF family ACL (Access Control List)1

nordic,nrf-acl

on-chip

Nordic nRF family MWU (Memory Watch Unit)1

nordic,nrf-mwu

Audio

on-chip

Nordic PDM (Pulse Density Modulation interface)1

nordic,nrf-pdm

Clock control

on-chip

Nordic nRF clock control node1

nordic,nrf-clock

on-chip

Nordic nRF high-frequency crystal oscillator (nRF52 series)1

nordic,nrf52-hfxo

Comparator

on-chip

Nordic nRF COMP (analog COMParator)1

nordic,nrf-comp

Counter

on-chip

Nordic nRF timer node5

nordic,nrf-timer

Cryptographic accelerator

on-chip

Nordic ECB (AES electronic codebook mode encryption)1

nordic,nrf-ecb

on-chip

Nordic nRF family CCM (AES CCM mode encryption)1

nordic,nrf-ccm

on-chip

ARM TrustZone CryptoCell 3101

arm,cryptocell-310

Debug

on-chip

ARMv7 instrumentation trace macrocell1

arm,armv7m-itm

Display

on-board

Sitronix ST7789V display controller1

sitronix,st7789v

Flash controller

on-chip

Nordic NVMC (Non-Volatile Memory Controller)1

nordic,nrf52-flash-controller

on-chip

Properties defining the interface for the Nordic QSPI peripheral1

nordic,nrf-qspi

GNSS

on-board

Generic GNSS NMEA receiver1

gnss-nmea-generic

GPIO & Headers

on-chip

NRF5 GPIOTE1

nordic,nrf-gpiote

on-chip

NRF5 GPIO2

nordic,nrf-gpio

I2C

on-chip

Nordic nRF family TWIM (TWI master with EasyDMA)2

nordic,nrf-twim

I2S

on-chip

Nordic I2S (Inter-IC sound interface)1

nordic,nrf-i2s

IEEE 802.15.4

on-chip

Nordic nRF IEEE 802.15.4 node1

nordic,nrf-ieee802154

Input

on-board

Group of GPIO-bound input keys1

gpio-keys

Interrupt controller

on-chip

ARMv7-M NVIC (Nested Vectored Interrupt Controller)1

arm,v7m-nvic

LED

on-board

Group of GPIO-controlled LEDs1

gpio-leds

LED strip

on-board

Worldsemi WS2812 LED strip, GPIO binding1

worldsemi,ws2812-gpio

LoRa

on-board

Semtech SX1262 LoRa Modem1

semtech,sx1262

Miscellaneous

on-chip

Nordic FICR (Factory Information Configuration Registers)1

nordic,nrf-ficr

on-chip

Nordic nRF family PPI (Programmable Peripheral Interconnect)1

nordic,nrf-ppi

MTD

on-chip

Flash node1

soc-nv-flash

on-chip

Fixed partitions of a flash (or other non-volatile storage) memory1

fixed-partitions

Networking

on-chip

Nordic nRF family RADIO peripheral1

nordic,nrf-radio

on-chip

Nordic nRF family NFCT (Near Field Communication Tag)1

nordic,nrf-nfct

Pin control

on-chip

Nordic nRF family Pin Controller1

nordic,nrf-pinctrl

Power management

on-chip

Nordic nRF power control node1

nordic,nrf-power

PWM

on-chip

nRF PWM4

nordic,nrf-pwm

on-chip

nRFx S/W PWM1

nordic,nrf-sw-pwm

Regulator

on-chip

Nordic nRF5X regulator (fixed stage of the core supply)1

nordic,nrf5x-regulator

on-chip

Nordic nRF52X regulator (high voltage stage of the main supply)1

nordic,nrf52x-regulator-hv

Retained memory

on-chip

Nordic GPREGRET (General Purpose Register Retention) device2

nordic,nrf-gpregret

RNG

on-chip

Nordic nRF family RNG (Random Number Generator)1

nordic,nrf-rng

RTC

on-chip

Nordic nRF RTC (Real-Time Counter)3

nordic,nrf-rtc

Sensors

on-chip

Nordic nRF family TEMP node1

nordic,nrf-temp

on-chip

Nordic nRF quadrature decoder (QDEC) node1

nordic,nrf-qdec

Serial controller

on-chip

Nordic nRF family UARTE (UART with EasyDMA)11

nordic,nrf-uarte

SPI

on-chip

Nordic nRF family SPIM (SPI master with EasyDMA)12

nordic,nrf-spim

on-chip

Nordic nRF family SPI (SPI master)1

nordic,nrf-spi

SRAM

on-chip

Generic on-chip SRAM1

mmio-sram

Timer

on-chip

ARMv7-M System Tick1

arm,armv7m-systick

USB

on-chip

Nordic nRF52 USB device controller1

nordic,nrf-usbd

Watchdog

on-chip

Nordic nRF family WDT (Watchdog Timer)1

nordic,nrf-wdt

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 rtt debugserver attach reset
jlink ✅ (default)
pyocd
uf2 ✅ (default)

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