LoRaWAN Connectivity
Built-in support for LoRaWAN OTAA with the RFM95 868MHz radio module, enabling long-range wireless communication.
Multiflexmeter 3.7.0 Documentation
Open-source IoT sensor platform for flexible, low-cost, and frequent environmental measurements using LoRaWAN.
What is Multiflexmeter?
Section titled “What is Multiflexmeter?”Multiflexmeter 3.7.0 (MFM) is an open-source sensor platform designed for frequent, low-cost, and flexible environmental measurements. Built on the ATmega1284P microcontroller, it provides a robust foundation for IoT deployments using LoRaWAN connectivity.
Key Features
Section titled “Key Features”Flexible Sensor Integration
SMBus/I2C interface for connecting external sensor modules. Firmware acts as a passthrough, transmitting raw sensor data for application-level processing.
Low Power Design
Optimized for battery-powered deployments with efficient power management and configurable measurement intervals.
Open Source Hardware & Firmware
Complete hardware designs (KiCad) and C++ firmware source code (PlatformIO) available under MIT license.
Firmware Technology Stack
Section titled “Firmware Technology Stack”The Multiflexmeter 3.7.0 firmware is built using modern C++ development tools:
- Language: C++ with Arduino Framework
- Build System: PlatformIO - Professional build tool for embedded systems
- IDE: VS Code with PlatformIO extension (recommended)
- LoRaWAN Library: MCCI Arduino-LMIC
- Toolchain: AVR-GCC cross-compiler
- Programming: AVRDude with ISP programmer
Technical Specifications
Section titled “Technical Specifications”- Microcontroller: ATmega1284P (128KB Flash, 16KB SRAM, 4KB EEPROM)
- Radio: RFM95 LoRa transceiver (868MHz)
- Connectivity: LoRaWAN 1.0.x with OTAA
- Sensor Interface: SMBus/I2C for external modules
- Programming: AVRISP-compatible ISP interface
- Debug: FTDI-compatible UART header
- Framework: Arduino with LMIC library
Quick Links
Section titled “Quick Links”🚀 Quick Start
Get your first Multiflexmeter device operational in minutes.
🔧 Hardware
Detailed hardware specifications, pin mappings, and schematics.
💻 Firmware Development
Build, modify, and extend the C++ firmware with PlatformIO.
📡 Communication Protocol
Understand LoRaWAN messages, payload formats, and commands.
Use Cases
Section titled “Use Cases”The Multiflexmeter platform is ideal for:
- Environmental Monitoring: Water level monitoring, distance measurements
- Infrastructure Monitoring: Structural health, asset tracking
- Research Projects: IoT experimentation and prototyping
- Custom Sensor Integration: Any I2C/SMBus compatible sensor module
Getting Help
Section titled “Getting Help”- GitHub Repository: MFM Documentation
- Issues & Discussion: Use GitHub discussions for questions
- Documentation: This site contains comprehensive guides and references
Version Information
Section titled “Version Information”Current Release: 3.7.0 & Planned Release: 3.8.0
- Architecture: Sensor Passthrough (unchanged between versions)
- Transmits raw sensor data without firmware-level interpretation
- Data format defined by sensor module at I2C address 0x36
- Application layer (TTN decoder + backend) handles data decoding
- Maximum 32-byte payload via SMBus Block Read
Design Philosophy: Keeping firmware simple as a passthrough minimizes complexity and allows flexible sensor integration. The sensor module encodes data, and the application layer decodes it.
Poldermill Sensor Format (Module Type 0x01):
- Byte 0: Module Address (0x36)
- Byte 1: Module Type (0x01 = Poldermill)
- Byte 2: Flags (bit 0: spinning, bit 1: pumping)
- Bytes 3-6: Revolutions (uint32 big-endian, period count)
Learn more about data formats →
Multiflexmeter 3.7.0 is licensed under the MIT License.