Finalised Break-out board

A project log for LR1110 module - Tiny LoRa & WiFi/GNSS positioning

Leveraging the LR1110 to create the smallest geolocation+LoRaWAN combined module for use in tracking.

SensorsSensors 07/01/2020 at 13:540 Comments

As I previously mentioned I had a concern about the existing break-out board design, especially if it were to be made available as a self-soldered kit since the u.Fl connectors and 0402 passives of the tuning networks can be difficult to solder. 

I'm pleased with the solution I settled upon which has two main updates:

  1. Removed the antenna tuning networks:  Without these the RF performance might not be ideal, but there are far too many variables involved at the prototyping stage to properly tune 3 antennae anyway, especially for LoRaWAN with various regional frequencies.
  2. Supports u.Fl and SMA connectors: This should give people the option to avoid soldering the fiddly u.FL connectors if they want to.

I've done my best to ensure the feed lines for the antennae are 50 ohm matched, but they're so short anyway the losses if unmatched will be negligible. I would have liked to support the two connector types simultaneously, but I can't think of how to achieve that without creating a stubthat would degrade RF performance.

The SMA connectors are pretty bulky, so if this is used on a breadboard it'd have to be placed at one end to give enough clearance below.

With u.FL connectors populated:

With SMA connectors populated:

And of course, all connections are labelled on the bottom: