/HomeMonNode-Shield-Arduino-Nano

Primary LanguagePLSQL

HomeMon Node Shield for Arduino Nano

This Eagle layout can be used to etch a single HomeMon node, in the form of a shield for the Arduino Nano prototyping platform.

The Arduino Nano sketch for this shield is available here.

Schematics
Top
Bottom

Features

  • Eleven pins can be used as general I/O (e.g. for reading data from sensors)
  • Two actuators can be driven by relays
  • A power supply bus (5V, 3.3V and ground lines) with fifteen pins is added for convenience
  • An NRF24L01+ 2.4 GHz transceiver is used for inter-node communication, and serial communication (either via the USB converter of the Arduino or, optionally, via an HC-05 based Bluetooth adapter allows the node to be connected to a desktop sink running the HomeMon Viewer Application
  • A trimmer can be used to set the analog voltage reference
  • Both the 2.4 GHz transceiver and the optional Bluetooth adapter can be turned on/off by switches (the Bluetooth adapter can additionally be put into AT mode for configuration purposes).

Pinout

  • Serial pins (D0 and D1): Bluetooth adapter
  • SPI pins (D11 to D13), D2, D8 and D9 pins: radio transceiver
  • Analog pins (A0 to A7): directly connected to the SENSORS connector
  • Digital pins D2 to D5: directly connected to the SENSORS connector. (Important note: pin D2 is also connected to the IRQ pin of the transceiver)
  • Digital pins D6 and D7: connected to the actuator connectors (ACT1 and ACT2 respectively) through two relays
  • AREF: connected to the analog reference trimmer
  • GND, 3V3 and 5V: connected to the power supply connectors
  • RST, VIN and D10: unconnected.

Bill of materials

  • 1x 10k linear trimmer
  • 1x Arduino Nano
  • 2x Diodes with DO-41 package (e.g. 1N4004)
  • 1x DIP switch SPST 1 position (RS-Components code: 877-2100)
  • 2x Monostable 5V DC G5LE relays (RS-Components code: 808-8465)
  • 2x NPN transistors with TO-92 package (e.g. 2N3904)
  • 1x NRF24L01+ module (8 pins breakout board)
  • 2x Two-ways PCB terminal blocks with 5.08mm pitch (RS-Components code: 425-8720)

Optionally, for Bluetooth support:

  • 1x DIP switch SPST 2 positions (RS-Components code: 877-2113)
  • 1x HC-05 Bluetooth module (6 pins breakout board)

Remarks

  • The shield relies on the Arduino for power supply (i.e. it doesn't have batteries nor a DC connector, energy must be supplied from the USB connector or the VIN pin)
  • Arduino pin D10 (SS) is left unconnected because the SPI library may malfunction if the pin is set to high when the Arduino is acting as SPI master
  • The additional components are defined in the freely available DIYmodules.org component library.