|
| 1 | +--- |
| 2 | +title: Heltec WiFi LoRa 32 V3 |
| 3 | +date-published: 2025-11-17 |
| 4 | +type: misc |
| 5 | +standard: Global |
| 6 | +board: esp32 |
| 7 | +--- |
| 8 | + |
| 9 | + |
| 10 | + |
| 11 | +Model reference: WiFi LoRa 32 V3 |
| 12 | + |
| 13 | +Manufacturer: [Heltec Automation](https://heltec.org/project/wifi-lora-32-v3/) |
| 14 | + |
| 15 | +## Product Description |
| 16 | + |
| 17 | +The Heltec WiFi LoRa 32 V3 is a development board featuring an ESP32-S3 microcontroller with integrated WiFi, |
| 18 | +Bluetooth, and a Semtech SX1262 LoRa radio transceiver. It includes a 0.96" OLED display and is designed for |
| 19 | +IoT applications requiring long-range wireless communication. |
| 20 | + |
| 21 | +### Key Features |
| 22 | + |
| 23 | +- ESP32-S3 dual-core processor @ 240MHz |
| 24 | +- 8MB Flash memory |
| 25 | +- SX1262 LoRa radio (433MHz or 868/915MHz variants) |
| 26 | +- 0.96" OLED display (128x64) |
| 27 | +- WiFi 802.11 b/g/n |
| 28 | +- Bluetooth 5 (LE) |
| 29 | +- USB-C connector |
| 30 | +- LiPo battery connector with charging circuit |
| 31 | +- Onboard CP2102 USB-to-UART bridge |
| 32 | + |
| 33 | +## GPIO Pinout |
| 34 | + |
| 35 | +### LoRa SX1262 Pins |
| 36 | + |
| 37 | +| Function | GPIO | |
| 38 | +|----------|------| |
| 39 | +| SPI CLK | GPIO9 | |
| 40 | +| SPI MOSI | GPIO10 | |
| 41 | +| SPI MISO | GPIO11 | |
| 42 | +| CS | GPIO8 | |
| 43 | +| RST | GPIO12 | |
| 44 | +| BUSY | GPIO13 | |
| 45 | +| DIO1 | GPIO14 | |
| 46 | + |
| 47 | +### Display (OLED) |
| 48 | + |
| 49 | +| Function | GPIO | |
| 50 | +|----------|------| |
| 51 | +| SDA | GPIO17 | |
| 52 | +| SCL | GPIO18 | |
| 53 | +| RST | GPIO21 | |
| 54 | + |
| 55 | +### Other Pins |
| 56 | + |
| 57 | +| Function | GPIO | |
| 58 | +|----------|------| |
| 59 | +| Button | GPIO0 | |
| 60 | +| LED | GPIO35 | |
| 61 | +| Battery ADC | GPIO1 | |
| 62 | +| Vext Control | GPIO36 | |
| 63 | + |
| 64 | +## Basic Configuration |
| 65 | + |
| 66 | +Minimum configuration required for the Heltec WiFi LoRa 32 V3: |
| 67 | + |
| 68 | +```yaml |
| 69 | +esphome: |
| 70 | + name: "heltec" |
| 71 | + |
| 72 | +esp32: |
| 73 | + variant: esp32s3 |
| 74 | + flash_size: 8MB |
| 75 | + cpu_frequency: 240MHZ |
| 76 | + framework: |
| 77 | + type: esp-idf |
| 78 | + |
| 79 | +logger: |
| 80 | + hardware_uart: UART0 |
| 81 | + |
| 82 | +api: |
| 83 | + |
| 84 | +ota: |
| 85 | + platform: esphome |
| 86 | + |
| 87 | +wifi: |
| 88 | + ssid: !secret wifi_ssid |
| 89 | + password: !secret wifi_password |
| 90 | + |
| 91 | +# SPI bus for LoRa radio |
| 92 | +spi: |
| 93 | + clk_pin: GPIO9 |
| 94 | + mosi_pin: GPIO10 |
| 95 | + miso_pin: GPIO11 |
| 96 | + |
| 97 | +# I2C for OLED display |
| 98 | +i2c: |
| 99 | + sda: GPIO17 |
| 100 | + scl: GPIO18 |
| 101 | + frequency: 400kHz |
| 102 | +``` |
| 103 | +
|
| 104 | +## LoRa Radio Configuration |
| 105 | +
|
| 106 | +```yaml |
| 107 | +# LoRa Radio Configuration (SX1262) |
| 108 | +sx126x: |
| 109 | + dio1_pin: GPIO14 |
| 110 | + cs_pin: GPIO8 |
| 111 | + busy_pin: GPIO13 |
| 112 | + rst_pin: GPIO12 |
| 113 | + pa_power: 3 |
| 114 | + bandwidth: 125_0kHz |
| 115 | + crc_enable: true |
| 116 | + frequency: 433920000 |
| 117 | + modulation: LORA |
| 118 | + rx_start: true |
| 119 | + hw_version: sx1262 |
| 120 | + rf_switch: true |
| 121 | + sync_value: [0x14, 0x24] |
| 122 | + preamble_size: 8 |
| 123 | + spreading_factor: 7 |
| 124 | + coding_rate: CR_4_6 |
| 125 | + tcxo_voltage: 1_8V |
| 126 | + tcxo_delay: 5ms |
| 127 | + on_packet: |
| 128 | + - lambda: |- |
| 129 | + ESP_LOGD("lora", "Received packet RSSI: %.2f dBm, SNR: %.2f dB, Data: %s", |
| 130 | + rssi, snr, format_hex(x).c_str()); |
| 131 | +
|
| 132 | +# Example button to send LoRa packet |
| 133 | +button: |
| 134 | + - platform: template |
| 135 | + name: "Send LoRa Packet" |
| 136 | + on_press: |
| 137 | + then: |
| 138 | + - sx126x.send_packet: |
| 139 | + data: [0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE, 0xBA, 0xBE] |
| 140 | +``` |
| 141 | +
|
| 142 | +## FSK Modulation Configuration |
| 143 | +
|
| 144 | +```yaml |
| 145 | +# FSK Radio Configuration (SX1262) |
| 146 | +sx126x: |
| 147 | + dio1_pin: GPIO14 |
| 148 | + cs_pin: GPIO8 |
| 149 | + busy_pin: GPIO13 |
| 150 | + rst_pin: GPIO12 |
| 151 | + pa_power: 3 |
| 152 | + bandwidth: 78_2kHz |
| 153 | + crc_enable: true |
| 154 | + frequency: 433920000 |
| 155 | + modulation: FSK |
| 156 | + rx_start: true |
| 157 | + payload_length: 0 |
| 158 | + hw_version: sx1262 |
| 159 | + bitrate: 4800 |
| 160 | + rf_switch: true |
| 161 | + sync_value: [0x33, 0x33] |
| 162 | + preamble_size: 4 |
| 163 | + preamble_detect: 2 |
| 164 | + tcxo_voltage: 1_8V |
| 165 | + tcxo_delay: 5ms |
| 166 | + on_packet: |
| 167 | + then: |
| 168 | + - lambda: |- |
| 169 | + ESP_LOGD("fsk", "Packet RSSI: %.2f dBm, SNR: %.2f dB, Data: %s", |
| 170 | + rssi, snr, format_hex(x).c_str()); |
| 171 | +
|
| 172 | +button: |
| 173 | + - platform: template |
| 174 | + name: "Send FSK Packet" |
| 175 | + on_press: |
| 176 | + then: |
| 177 | + - sx126x.send_packet: |
| 178 | + data: [0xC5, 0x51, 0x78, 0x82, 0xB7, 0xF9, 0x9C, 0x5C] |
| 179 | +``` |
| 180 | +
|
| 181 | +## OLED Display Configuration |
| 182 | +
|
| 183 | +Configuration to use the onboard 0.96" OLED display: |
| 184 | +
|
| 185 | +```yaml |
| 186 | +# OLED Display |
| 187 | +display: |
| 188 | + - platform: ssd1306_i2c |
| 189 | + model: "SSD1306 128x64" |
| 190 | + reset_pin: GPIO21 |
| 191 | + address: 0x3C |
| 192 | + lambda: |- |
| 193 | + it.printf(0, 0, id(font), "Heltec V3"); |
| 194 | + it.printf(0, 16, id(font), "WiFi LoRa 32"); |
| 195 | + it.printf(0, 32, id(font), "%.1f dBm", id(wifi_signal_db).state); |
| 196 | +
|
| 197 | +font: |
| 198 | + - file: "gfonts://Roboto" |
| 199 | + id: font |
| 200 | + size: 14 |
| 201 | + |
| 202 | +sensor: |
| 203 | + - platform: wifi_signal |
| 204 | + id: wifi_signal_db |
| 205 | + name: "WiFi Signal" |
| 206 | + update_interval: 60s |
| 207 | +``` |
| 208 | +
|
| 209 | +## Battery Monitoring |
| 210 | +
|
| 211 | +Configuration to monitor LiPo battery voltage: |
| 212 | +
|
| 213 | +```yaml |
| 214 | +sensor: |
| 215 | + - platform: adc |
| 216 | + pin: GPIO1 |
| 217 | + name: "Battery Voltage" |
| 218 | + attenuation: 12db |
| 219 | + filters: |
| 220 | + - multiply: 2.0 # Voltage divider correction |
| 221 | + update_interval: 60s |
| 222 | +``` |
| 223 | +
|
| 224 | +## Power Management |
| 225 | +
|
| 226 | +The Vext pin (GPIO36) controls power to external peripherals. Set it LOW to enable power: |
| 227 | +
|
| 228 | +```yaml |
| 229 | +switch: |
| 230 | + - platform: gpio |
| 231 | + pin: GPIO36 |
| 232 | + id: vext |
| 233 | + name: "Vext Control" |
| 234 | + inverted: true |
| 235 | + restore_mode: ALWAYS_ON |
| 236 | +``` |
| 237 | +
|
| 238 | +## Links |
| 239 | +
|
| 240 | +- [Product Page](https://heltec.org/project/wifi-lora-32-v3/) |
| 241 | +- [Pinout Diagram](https://resource.heltec.cn/download/WiFi_LoRa_32_V3/HTIT-WB32LA(F)_V3.png) |
| 242 | +- [Schematic](https://resource.heltec.cn/download/WiFi_LoRa_32_V3/HTIT-WB32LA(F)_V3_Schematic_Diagram.pdf) |
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