Heltec WiFi LoRa 32 V2

The Heltec WiFi LoRa32 is a development board based on an ESP32 microcontroller. It is designed for LoRa application.

../../../../../_images/wifi-lora-32-v2.png — Heltec WiFi LoRa32 V2

Features

ESP32 (240MHz Tensilica LX6 dual-core+1 ULP, 600 DMIPS)

LoRa Node Chip SX1276/SX1278

OLED Display

Battery Charger 3.7V lithium (SH1.25 x 2 socket)

LoRa ANT(IPEX1.0)

Pinout

Most of I/O pins are broken out to the header pins as displayed here:

Schematic

https://resource.heltec.cn/download/WiFi_LoRa_32/V2/WiFi_LoRa_32_V2(433%2C470-510).PDF

Serial Console

UART0 is, by default, the serial console. It connects to the on-board CP2102 converter.

Buttons and LEDs

Board Buttons

There are two buttons labeled BOOT and RST. The RST button is not available to software. It pulls the chip enable line that doubles as a reset line.

The BOOT button is connected to IO0. On reset it is used as a strapping pin to determine whether the chip boots normally or into the serial bootloader. After reset, however, the BOOT button can be used for software input.

Board LEDs

There is one LED available connected to IO25.

Configurations and Flashing

All of the configurations presented below can be tested by running the following commands:

$ ./tools/configure.sh heltec_wifi_lora32:<config_name>

Where <config_name> is the name of board configuration you want to use, i.e.: nsh, buttons, wifi…

Flashing is done in the default way for ESP32 boards using:

$ make flash ESPTOOL_PORT=/dev/ttyUSB0 -j

Then use a serial console terminal like minicom or picocom` configured to 115200 8N1.

nsh

Basic NuttShell configuration (console enabled in UART0, exposed via USB connection by means of CH340 converter, at 115200 bps).

sx1276

This board profile enables the SX1276 transceiver to RX and TX (half-duplex) communication using FSK protocol.

In order to test it you need to flash two boards with this same firmware.

Board 1 will be the transmitter, then execute:

nsh> sx127x -m 1 -t

Board 2 will be the receiver, then execute:

nsh> sx127x -m 1

Note: The default configuration is to 915MHz, you need to change the configuration if your boards are using other frequencies.