Advanced Arduino Relay Shield: the Bmini

The All-in-one BMini shield is an advanced expansion board designed specifically for Arduino. It lets you create independent and intelligent units that control motors, reads temperature probes, dims LEDs, manages 24VDC digital inputs.

Arduino Relay Shield Ethernet RS485 Bmini

Compatibility. Arduino Uno, Mini and Ethernet.

This expansion shield is compatible with the small sized Arduino Mini 05, Uno and Ethernet. If you already know how to program an Arduino, you have done. You don’t need to learn new things, the syntax is the same.This shield has been designed specifically for home and industrial applications and environments. It helps you to automate every day task and make life easier. Check our wiki for details, code examples and libraries and success stories.

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Power supply. 24V

  • 24V DC or AC
  • Separated power inputs for the Arduino board and for the digital inputs. No electrical noise and current peaks will alter the Arduino board
  • 2 fuses for the supply voltage
  • 5V power output for external sensors
  • 24V power supply with two different connector plug IN/OUT configuration. Connect the 24V to the first BMini (J3 connector) and use the J4 for powering the following BMini in the network
24V power supply

Bmini I/O

I/O. Analog Inputs

The Bmini can be easily extended by using the BmAna converter to read the following analog inputs:

  • 0-20ma (current)
  • 0-10V (tension)
  • PTC (thermocouples)
  • NTC (thermocouples)

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I/O. Digital and analog

  • 4 high quality relays (40.52): output 24VDC max 5A, 230V max 8A
  • 4 fuses for relays
  • 4 opto-iso­lated dig­i­tal inputs
  • 8 ana­log inputs (0-5V) (can act as digital inputs/outputs)
  • 2 PWM outputs
  • I2C bus
  • 4 LEDs for digital inputs status
Bmini I/O

Arduino Relay Network RS485

Interfaces. Ethernet, RS485 and Modbus

Feel free to connect as many BMini shields as you want in a network of intelligent devices (but not only BMini shields) that can easily communicate through RS485 bus (modbus protocol) or Ethernet (socket converter included).

  • Ethernet (using the socket converter included)
  • RS485 bus line (120-Ohm resistor included)
  • Maxim MAX 1487 transceiver
  • One LED for modbus status

Electrical noises. The most important rules

  • Maximization of PCB Ground area
  • Functional grouping of components for EMI control
  • Optoisolated digital inputs
  • Short tracks for limiting radiation and crosstalk issues
  • Analog inputs far from noise sources
  • Capacitors split for removing any high frequency noises

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Arduino Bmini electrical noise reduction

How-to: Connecting the microcontroller.

The Bmini shield supports many Arduino boards like for instance Mini 05, Uno and Ethernet. The video shows how simple is to connect those boards to the Bmini. In particular, we showed how to use the socket converter in order to use Uno and Ethernet.

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Let’s see it in action. Some Video Examples.

The video shows how to use the Bmini shield together with Arduino Ethernet Board in order to create a lightweight webserver to control remotely your devices.

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