Octave Modbus Wrapper

What is this repository for?

• This repository was created to develop an Arduino wrapper for Modbus communication with Arad Octave ultrasonic water meters.

It is compatible with ESP32- and Arduino-based microcontrollers, using any TTL-to-RS485 converter that can be interfaced via UART, and Arad Octave meters versions 4.02 and up.

This project is based on the Modbus RTU library developed by Industrial Shields.

Arad Octave water meters info

• Documentation page
• See Octave Memory Map.md for explanatory notes about the Modbus memory map implemented in Octave water meters

How do I set up?

• Install Git
• Install Arduino IDE
• If using ESP32-based microcontrollers, follow these instructions for Arduino IDE support
• If using Arduino-based microcontrollers, install fp64lib via the library manager
• Clone this repo and upload main.ino to the ESP32
• Use an Octave NFC reader to configure the water meter's Modbus slave address, baud rate, parity, and other variables
• Modify the MODBUS_SLAVE_ADDRESS in OctaveModbusWrapper.h accordingly
• #import OctaveModbusWrapper/ESP32/OctaveModbusWrapper.h or #import OctaveModbusWrapper/Arduino/OctaveModbusWrapper.h in your Arduino code file
• Create a Serial-like object (either Hardware- or SoftwareSerial work) with the appropiate baud rate and parity that can interface via RS-485 with the Modbus module, most commonly using a TTL-to-RS485 module
• Create an OctaveModbusWrapper object with the Serial as a parameter, for example:

// Define the HardwareSerial used as an RS-485 port
HardwareSerial RS485(0);
// Define the OctaveModbusWrapper object, using the RS-485 port for Modbus
OctaveModbusWrapper octave(RS485);

• begin() the Serial and OctaveModbusWrapper objects, i.e.:

// Start the Modbus serial port
RS485.begin(MODBUS_BAUDRATE, SERIAL_8N1, RS485_RX_PIN, RS485_TX_PIN);
// Set RTS pin
RS485.setPins(RS485_RX_PIN, RS485_TX_PIN, -1, RS485_RTS_PIN);
// Disable hardware flow control, as required by the documentation,
// and set the TX buffer size threshold to 128 bytes (maximum value)
RS485.setHwFlowCtrlMode(UART_HW_FLOWCTRL_DISABLE, 128);
// Enable half-duplex flow control
RS485.setMode(UART_MODE_RS485_HALF_DUPLEX);

// Start the Octave Modbus object
octave.begin(MODBUS_BAUDRATE);

Contribution guidelines

• If you want to propose a change or need to modify the code for any reason first clone this repository to your PC and create a new branch for your changes. Once your changes are complete and fully tested ask the administrator permission to push this new branch into the source.
• If you just want to do local changes instead you can download a zip version of the repository and do all changes locally in your PC.

Who do I talk to?

• Juan J. Rojas
• Anthony Arguedas