Hardware Overview¶
Espilon supports a wide range of ESP32-based development boards. Choose the right board for your deployment scenario.
Recommended Boards¶
LilyGO T-Call (GPRS Mode)¶
Official Espilon board for cellular deployments
- Integrated SIM800 2G modem
- No external wiring required
- Built-in power management
- Battery support via JST connector
Best For: Remote deployments, mobile operations, areas without WiFi
ESP32-DevKit (WiFi Mode)¶
Budget-friendly option for WiFi deployments
- Standard ESP32-WROOM-32
- Available from many vendors
- USB-C or Micro-USB variants
- Easy to source worldwide
Best For: Labs, buildings with WiFi, development/testing
Quick Comparison¶
| Feature | LilyGO T-Call | ESP32-DevKit |
|---|---|---|
| Price | ~$18 USD | ~$5-8 USD |
| Network | WiFi + GPRS (2G) | WiFi only |
| Range | Nationwide cellular | 50-100m WiFi |
| Wiring | None (integrated) | None (USB) |
| Battery | JST connector | External required |
| Setup | Moderate | Simple |
| Best For | Remote/mobile | Labs/buildings |
Minimum Requirements¶
All ESP32 boards for Espilon must have:
- ESP32 chip (ESP32-WROOM, ESP32-WROVER, or variant)
- 4MB Flash minimum (8MB recommended)
- USB-to-UART converter (for flashing)
- WiFi support (built-in to all ESP32)
Optional Features¶
Enhance functionality with:
- PSRAM: 4MB+ for camera or large buffers
- Camera: ESP32-CAM for reconnaissance
- External Antenna: Better WiFi/cellular range
- Battery Connector: Portable operation
- GPIOs: Exposed pins for custom sensors
Connectivity Options¶
WiFi Mode¶
Standard 802.11 b/g/n connectivity:
- Frequency: 2.4 GHz
- Range: 50-100m (indoor), 300m+ (outdoor)
- Speed: Up to 150 Mbps
- Security: WPA/WPA2/WPA3
- Cost: Free (existing infrastructure)
Required: ESP32 with WiFi (all models)
GPRS Mode¶
2G cellular connectivity via SIM800:
- Frequency: 850/900/1800/1900 MHz (quad-band)
- Range: Nationwide (cell tower coverage)
- Speed: ~50 Kbps (GPRS Class 10)
- Cost: SIM card + data plan ($5-15/month)
Required: LilyGO T-Call or external SIM800 module
Power Requirements¶
USB-Powered¶
- Voltage: 5V
- Current: 500mA - 1A
- Connector: USB-C or Micro-USB
- Best For: Development, testing, fixed installations
Battery-Powered¶
- Type: Li-Po 3.7V
- Capacity: 1000-2000mAh recommended
- Runtime: 5-14 hours (depending on activity)
- Best For: Mobile deployments, covert operations
GPIO Availability¶
Most ESP32 boards expose 20-30 GPIOs for custom use:
- Digital I/O: 34 pins
- ADC: 18 channels
- DAC: 2 channels
- PWM: All pins
- UART: 3 ports
- SPI: 4 ports
- I2C: 2 ports
Reserved pins (varies by board): - Flash: GPIOs 6-11 - UART0 (USB): GPIOs 1, 3 - Strapping: GPIOs 0, 2, 5, 12, 15
Antenna Considerations¶
Built-in PCB Antenna¶
Most ESP32 boards include a PCB trace antenna:
- Range: Adequate for labs and buildings
- Cost: Free (included)
- Limitation: Fixed position, limited gain
External Antenna¶
For better range and performance:
- WiFi: 2.4 GHz antenna with U.FL/IPEX connector
- GPRS: GSM quad-band antenna (included with T-Call)
- Gain: 2-9 dBi depending on model
- Range: 2-5x improvement
Antenna Requirement
LilyGO T-Call requires external GSM antenna. Never power on without antenna connected.
Purchasing Guide¶
Official Sources¶
- Espressif: espressif.com
- LilyGO: lilygo.cc
Distributors¶
- Mouser: Global, reliable shipping
- DigiKey: Large stock, fast shipping
- AliExpress: Budget option, slower shipping
- Amazon: Fast shipping, higher prices
Verification¶
Always buy from: - Official stores - Authorized distributors - Verified sellers with reviews
Avoid: - Suspiciously cheap "clones" - Unknown sellers - Boards without documentation
Next Steps¶
- LilyGO T-Call Setup - For GPRS deployments
- Supported Boards - Full compatibility list
- Configuration Guide - Configure your board
Previous: Installation | Next: LilyGO T-Call