# Heltec HT-CT62 > Ultra-compact ESP32-C3 + SX1262 LoRa/LoRaWAN module with WiFi and BLE, designed for SMT integration into IoT devices. Features 10uA deep sleep, +21dBm TX power, and Meshtastic compatibility in a tiny 17.78mm stamp-hole package. ## Quick Facts - **Brand:** Heltec Automation - **Board Type:** module - **Price:** ~$6.9 - **CPU:** RISC-V RV32IMC single-core @ 160MHz, HW crypto (AES-128,256, SHA, RSA, HMAC, ECDSA) - **CPU Architecture:** RISC-V - **CPU Cores:** 1 - **RAM:** 400KB SRAM - **Flash:** 4MB SiP - **USB:** None (requires external USB-to-UART bridge) - **Power:** 3.3V - **Operating Voltage:** 3.3V - **Operating Temp:** -40°C to +85°C - **Dimensions:** 17.78 × 17.78 × 2.8mm - **Weight:** 2g - **Antenna:** IPEX 1.0 (U.FL) x2 (WiFi,LoRa) - **SD Card:** No ## Connectivity - **Wifi:** 802.11 b/g/n 2.4GHz - **Bluetooth:** BLE 5.0 - **Lora:** SX1262 433/868/915MHz ## Use Cases - lora-mesh-networking - off-grid-communication - lorawan-node - iot-sensor-node - wireless-sensor-node - smart-agriculture - remote-sensor-nodes - lora-telemetry ## Components - **ESP32-C3FN4** (mcu): Espressif ESP32-C3FN4 single-core RISC-V RV32IMC microcontroller at 160MHz with 400KB SRAM, 4MB SiP flash, WiFi 802.11 b/g/n, BLE 5.0, and hardware cryptographic acceleration (AES/SHA/RSA/HMAC/ECDSA). — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2Fesp32-c3_datasheet_en.pdf&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) - **SX1262** (radio): Semtech SX1262 LoRa transceiver supporting 150–960MHz frequency range with +22dBm maximum output power, -134dBm sensitivity, and TCXO for stable frequency reference. Supports LoRa and FSK modulation. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fcdn.sparkfun.com%2Fassets%2F6%2Fb%2F5%2F1%2F4%2FSX1262_datasheet.pdf&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) ## Protocols - **SPI** (SPI (LoRa)): SCK: GPIO10, MOSI: GPIO7, MISO: GPIO6, CS: GPIO8 - **UART** (UART0): TX: GPIO21, RX: GPIO20 - **I2C**: SDA: GPIO1, SCL: GPIO0 - **ADC** ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | GPIO0 | I2C SCL / ADC1_CH0 | I2C | digital-input, digital-output, adc, pwm, i2c | | GPIO1 | I2C SDA / ADC1_CH1 | I2C | digital-input, digital-output, adc, pwm, i2c | | GPIO2 | LED / ADC1_CH2 | — | digital-input, digital-output, adc, pwm | | GPIO3 | LoRa DIO1 / ADC1_CH3 | LoRa IRQ | digital-input, digital-output, adc, pwm | | GPIO4 | LoRa BUSY / ADC1_CH4 | LoRa | digital-input, digital-output, adc, pwm | | GPIO5 | LoRa RESET / ADC2_CH0 | LoRa | digital-input, digital-output, adc, pwm | | GPIO6 | SPI MISO (LoRa) | SPI | digital-input, digital-output, pwm | | GPIO7 | SPI MOSI (LoRa) | SPI | digital-input, digital-output, pwm | | GPIO8 | SPI CS (LoRa) | SPI | digital-input, digital-output, pwm | | GPIO9 | Boot Button | — | digital-input, digital-output, pwm, strapping | | GPIO10 | SPI SCK (LoRa) | SPI | digital-input, digital-output, pwm | | GPIO18 | USB D- | — | digital-input, digital-output | | GPIO19 | USB D+ | — | digital-input, digital-output | | GPIO20 | UART0 RX | UART | digital-input, digital-output, pwm | | GPIO21 | UART0 TX | UART | digital-input, digital-output, pwm | ## Description ## Overview The Heltec HT-CT62 is an ultra-compact LoRa/LoRaWAN node module combining the ESP32-C3FN4 RISC-V microcontroller with a Semtech SX1262 LoRa transceiver in a tiny 17.78 x 17.78mm stamp-hole package. Designed for SMT integration into custom PCBs, the module provides dual-mode wireless communication — 2.4GHz WiFi/BLE via the ESP32-C3 and long-range sub-GHz LoRa via the SX1262 — making it ideal for IoT sensor networks, Meshtastic mesh nodes, and LoRaWAN endpoints. The module achieves remarkable power efficiency with just 10uA deep sleep current, while delivering +21dBm LoRa transmit power and -134dBm receiver sensitivity for multi-kilometer range. Two IPEX 1.0 antenna connectors provide separate RF paths for WiFi and LoRa, ensuring optimal impedance matching and RF performance. The 1.27mm pitch stamp-hole edge design enables reliable automated soldering in production environments. At approximately $6.90 USD, the HT-CT62 is one of the most affordable ESP32+LoRa modules available, which has made it popular in the Meshtastic community for building low-cost mesh networking nodes. Community projects like CheapMesh and SolarMeshtasticNode demonstrate the module's versatility as a building block for off-grid communication devices, solar-powered remote sensor nodes, and compact LoRa repeaters. ## Where to Buy - [Heltec Official Store](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fht-ct62%2F&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) — 6.90 - [AliExpress](https://openhardware.directory/r?to=https%3A%2F%2Fwww.aliexpress.com%2Fitem%2F1005005442830223.html&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) — 6.60 - [Amazon](https://openhardware.directory/r?to=https%3A%2F%2Fwww.amazon.com%2FEC-Buying-HT-CT62-Wireless-ESP32C3%2Fdp%2FB0CB3X6JWS&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) — $6.90 ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fht-ct62%2F&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FHelTecAutomation%2FHeltecDocs&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) - [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fdocs.heltec.org%2Fen%2Fnode%2Fesp32%2Fht_ct62%2Findex.html&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) - [datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2FHT-CT62%2FHT-CT62%28Rev1.1%29.pdf&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) - [schematics](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2FHT-CT62%2FHT-CT62_Schematic_Diagram.pdf&ref=openhardware.directory&product=heltec-ht-ct62&source=md-export) ## Tags `esp32-c3`, `lora`, `lorawan`, `meshtastic`, `sx1262`, `iot`, `wifi`, `ble`, `risc-v`, `heltec` ## Images ![Heltec HT-CT62](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-ht-ct62/a83775f0f1a6.png) ![Heltec HT-CT62](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-ht-ct62/99f59aece2f7.png) ![Heltec HT-CT62](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-ht-ct62/8b6e903fa5d8.png) ![Heltec HT-CT62](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-ht-ct62/d48570a0f22f.png) --- [View full device page](https://openhardware.directory/devices/heltec-ht-ct62)