# Heltec Capsule Sensor V3

> Ultra-compact IP65 waterproof LoRa sensor capsule with ESP32-S3, SX1262 LoRa, GNSS, temperature/humidity, barometric pressure, and 3-axis accelerometer. Meshtastic-compatible with 250mAh battery and over 1 year battery life.

## Quick Facts

- **Brand:** heltec
- **CPU:** Xtensa LX7 dual-core @ 240MHz, FPU, vector instructions
- **CPU Architecture:** xtensa-lx7
- **CPU Cores:** 2
- **RAM:** 512KB SRAM
- **PSRAM:** No
- **Flash:** 8MB (QSPI)
- **USB:** None (WirelessBoot OTA via WiFi)
- **Power:** 3.7V lithium battery, 5V magnetic charging
- **Operating Voltage:** 3.3V
- **Operating Temp:** -20°C to +60°C
- **Dimensions:** 26 × 26 × 47mm (cylindrical)
- **Weight:** 23g
- **Battery:** 250mAh
- **Charging Port:** Magnetic 2-pin 2.54mm
- **Antenna:** Built-in PCB antennas (LoRa,WiFi/BLE)
- **SD Card:** No

## Connectivity

- **Wifi:** 802.11 b/g/n 2.4GHz
- **Bluetooth:** BLE 5.0, Bluetooth Mesh
- **Lora:** SX1262 863-870MHz / 902-928MHz / 470-510MHz,, 21dBm TX, -135dBm sensitivity

## Use Cases

- lora-mesh-networking
- meshtastic-mesh
- asset-tracking
- environmental-monitoring
- outdoor-environmental-sensor
- pet-tracker

## Components

- **ESP32-S3FN8** (mcu): Espressif ESP32-S3FN8 dual-core Xtensa LX7 at 240MHz with 8MB flash, WiFi 802.11 b/g/n and BLE 5.0. Provides the main processing, wireless connectivity, and deep sleep power management. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2Fesp32-s3_datasheet_en.pdf&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)
- **SX1262** (radio): Semtech SX1262 LoRa transceiver supporting 150-960MHz frequency bands with +21dBm TX power and -135dBm receive sensitivity for long-range communication up to 6km+ line-of-sight. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.semtech.com%2Fproducts%2Fwireless-rf%2Flora-connect%2Fsx1262&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)
- **L76K** (gps): Quectel L76K compact GNSS module supporting GPS, BeiDou, GLONASS, and QZSS with <2m CEP accuracy, cold start under 30s, and 5Hz update rate. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Ffiles.waveshare.com%2Fupload%2Fd%2Fdb%2FQuectel_L76K_Hardware_Design_V1.0.pdf&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)
- **GXHTC3** (sensor): GXCAS GXHTC3 temperature and humidity sensor with ±0.3°C temperature accuracy, ±3% RH humidity accuracy, 16-bit digital output via I2C. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2Fsensor%2FGXHTC3_EN_V2.4.pdf&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)
- **BMP280** (pressure-sensor): Bosch BMP280 digital barometric pressure sensor with ±1 hPa absolute accuracy and ±1°C temperature accuracy, useful for altitude estimation and weather monitoring. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.bosch-sensortec.com%2Fproducts%2Fenvironmental-sensors%2Fpressure-sensors%2Fbmp280%2F&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)
- **DA217** (accelerometer): MiraMEMS DA217 3-axis MEMS accelerometer with 14-bit resolution, selectable ±2g/±4g/±8g/±16g range, I2C interface for motion detection, tilt sensing, and activity recognition. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fgaupen1186%2FDA217_Driver%2Fblob%2Fmain%2FMira_DA217.pdf&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)

## Protocols

- **SPI** (SPI0): SS: GPIO8, MOSI: GPIO10, MISO: GPIO11, SCK: GPIO9
- **I2C**: SDA: GPIO41, SCL: GPIO42
- **UART** (UART0): TX: GPIO43, RX: GPIO44
- **UART** (UART1): TX: GPIO4, RX: GPIO5

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| GPIO1 | GPS PPS | Digital | digital-input, digital-output, adc, touch |
| GPIO3 | GPS Reset | Digital | digital-input, digital-output, adc, touch |
| GPIO4 | GPS TX | UART | digital-input, digital-output, adc, touch, pwm |
| GPIO5 | GPS RX | UART | digital-input, digital-output, adc, touch, pwm |
| GPIO7 | Battery ADC | ADC | digital-input, digital-output, adc, touch, pwm |
| GPIO8 | LoRa NSS (SPI CS) | SPI | digital-input, digital-output, touch, pwm |
| GPIO9 | LoRa SCK | SPI | digital-input, digital-output, touch, pwm |
| GPIO10 | LoRa MOSI | SPI | digital-input, digital-output, touch, pwm |
| GPIO11 | LoRa MISO | SPI | digital-input, digital-output, touch, pwm |
| GPIO12 | LoRa Reset | Digital | digital-input, digital-output, touch, pwm |
| GPIO13 | LoRa BUSY | Digital | digital-input, digital-output, touch, pwm |
| GPIO14 | LoRa DIO1 (IRQ) | Digital | digital-input, digital-output, touch, pwm |
| GPIO18 | User Button | Digital | digital-input, digital-output, pwm |
| GPIO21 | Vext Power Control | Digital | digital-input, digital-output, pwm |
| GPIO36 | Battery ADC Control | Digital | digital-input, digital-output, pwm |
| GPIO41 | I2C SDA (Sensors) | I2C | digital-input, digital-output, pwm |
| GPIO42 | I2C SCL (Sensors) | I2C | digital-input, digital-output, pwm |
| GPIO43 | UART TX (Debug) | UART | digital-input, digital-output, pwm |
| GPIO44 | UART RX (Debug) | UART | digital-input, digital-output, pwm |

## Description

## Overview

The Heltec Capsule Sensor V3 is a tiny, self-contained IoT sensor node built around the ESP32-S3 and Semtech SX1262 LoRa transceiver. Weighing just 23 grams and sealed to IP65, it is designed to be deployed outdoors in harsh conditions — hung from a lanyard, attached magnetically, or tucked into tight spaces where traditional dev boards cannot go. It ships with Meshtastic firmware pre-installed, enabling out-of-the-box mesh communication with no configuration required.

What sets the Capsule Sensor V3 apart is its modular sensor architecture. The main board connects to interchangeable sensor daughterboards via a BTB (board-to-board) connector, allowing users to swap between GNSS (Quectel L76K), temperature/humidity (GXHTC3), barometric pressure (BMP280), and 3-axis accelerometer (DA217) modules. This modularity means you can tailor the device to your specific use case — from asset tracking to weather monitoring to Meshtastic mesh networking — without soldering or redesigning hardware.

The device features Heltec's WirelessBoot technology, which enables firmware updates entirely over WiFi — no USB port or UART adapter needed. Combined with deep sleep current of approximately 15 uA and a 250 mAh rechargeable lithium battery, the Capsule Sensor V3 can operate for over a year on a single charge when transmitting sensor data via LoRa at typical intervals. The magnetic charging connector maintains the IP65 seal while making recharging effortless.

For developers, the Capsule Sensor V3 supports Arduino IDE and PlatformIO, with the full Heltec ESP32 library providing access to LoRa, WiFi, BLE, and all onboard sensors. The device is also compatible with Meshtastic, Paxcounter, and Disaster Radio firmware projects, making it a versatile platform for long-range IoT and mesh networking applications.

## Where to Buy

- [Heltec Official Store](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fheltec-capsule-sensor-v3%2F&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export) — $25.90
- [AliExpress (Heltec Official)](https://openhardware.directory/r?to=https%3A%2F%2Fwww.aliexpress.com%2Fitem%2F1005007033187034.html&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export) — $25.90

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fheltec-capsule-sensor-v3%2F&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FHelTecAutomation%2FHeltec_ESP32&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)
- [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fwiki.heltec.org%2Fdocs%2Fdevices%2Fopen-source-hardware%2Fesp32-series%2Flora-32%2Fcapsule-sensor-v3%2F&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)
- [datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2FHeltec%2520Capsule%2520Sensor%2520V3%2FCapSule%2520Sensor%2520V3.pdf&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)
- [schematics](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2FHeltec%2520Capsule%2520Sensor%2520V3%2FCapsule_Main_Esp32_Schematic_Diagram.pdf&ref=openhardware.directory&product=heltec-capsule-sensor-v3&source=md-export)

## Tags

`lorawan`, `meshtastic`, `esp32-s3`, `sx1262`, `gps`, `sensor`, `ip65`, `portable`, `iot`

## Images

![Heltec Capsule Sensor V3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-capsule-sensor-v3/4266529a4dfa.png)
![Heltec Capsule Sensor V3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-capsule-sensor-v3/92a96fcd2ff5.jpg)
![Heltec Capsule Sensor V3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-capsule-sensor-v3/891d0fe30a21.jpg)
![Heltec Capsule Sensor V3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-capsule-sensor-v3/ac14824eb719.jpg)
![Heltec Capsule Sensor V3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-capsule-sensor-v3/c31f0177b6aa.png)
![Heltec Capsule Sensor V3](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-capsule-sensor-v3/571b90fb2b56.jpg)

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