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jossiTech edited this page Aug 10, 2019 · 26 revisions

(#LoRaWAN #The Things Network # TTN Universal Node #ATmega 328p #RFM95W #Arduino #1 Wire Busses #I2C #DHT11)

Universal Node for The Things Network TTN, providing plenty different ports, programmable with Arduino IDE

Universal TTN Node

Introduction

I wanted a universal Node for The Things Network that provides different ports for different Purposes and I want it to be easily programmable with Arduino IDE, like a standard Arduino Board (eg. Arduino Uno). Furthermore I want that it fits in a suitable enclosure without the need to do Milling-Work on that enclosure.

The PCB provides the following Ports:

  • 1-Wire-Bus
  • I2C
  • Relais Port
  • DHT11 / DHT22 Socket for temperature and humidity
  • USB-B-Port for Input voltage
  • Socket to connect an FTDI-Module for uploading new sketches
  • SMA-Connector for Antenna

Universal TTN Node PCB Universal TTN Node PCB

The node consists of an ATmega328p Microcontroller and a RFM95W Radio to communicate with „The Things Network.“ The RFM95W-Radio-Model use 3.3 Volt, fortunately the 328p Microcontroller can also operate with 3.3V, so no level shifting is necessary.

I provide the EAGLE-Files, you can use and modify them as you wish. You find the files here.

But you can also purchase the PCB (or a Kit with all necessary components, 328p with burned bootloader and the enclosure) here on Tindie.

If you only need the enclosure you can find it easily by searching for "strabubox 524"

Assembling and Soldering the PCB

You find the necessary components in the Eagle-Files. Solder the components on the right position of the board, the positions are labeled. I have used no SMD-Devices, so you need no special devices to build the board, soldering the used components is not very difficult. :-)

Uploading a sketch to the PCB

Be aware that you need to burn a bootloader onto the ATmega328p. A suitable tutorial how to do this can be found on the Arduino-Webpage (Link). If you purchased the Kit from me on Tindie, the bootloader is already on the Microcontroller.

Connecting FTDI-Module

To upload sketches to the board simple connect a FTDI-Module to the FTDI-Connector-Port on the PCB, the FTDI-Module can be connected to an USB-Port on your computer so you can upload Arduino-Sketches from the Arduino IDE. Be aware to choose "Arduino Nano 328p" in the Arduino IDE and to configure the FTDI to use 3.3 Volt.

Select the right board in the Arduino IDE

Here you can find the sketch that works fine for the board, feel free to use and modify it for your needs.