Sensor Nodes

Simple mount for TLPHnodeV2

Jan 16, 2017. | By: Jerry

The pressure sensor on the TLPHnodeV2 is light sensitive and needs a cover. I’m not ready to commit to a full enclosure, so I designed a simpler cover for board bring-up and evaluation. The cover was designed using FreeCAD and is being printed at Shapeways.

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PCB Fabrication

Jan 12, 2017. | By: Jerry

These are my notes on how to get a PCB designed in KiCAD fabricated by OSH Park. The process is easy- there isn’t anything complex or tricky. I just like to have a reference to follow.

These notes were developed while ordering the TLPHnodeV2

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74880 baud - Redux

Jan 24, 2016. | By: Jerry

My hubris is showing: In ESP-8266, Ubuntu, and 74880 baud I solved my problem with 74880 baud the hard way. Rather than looking at the alternatives (and with Linux/Ubuntu there is always an alternative, and usually more than one) I assumed that other terminal programs would have a fixed list of speeds like minicom. Well, I was wrong.

Brian Walton pointed out that miniterm.py will accept 74800 baud. Furthermore, I already had miniterm.py installed!

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ESP-8266, Ubuntu, and 74880 baud

Jan 19, 2016. | By: Jerry

The ESP-8266 boot loader prints messages at 74880 baud. That is a non-standard baud rate which is not available as a stty setting on Ubuntu, so the messages just look like garbage. But, it doesn’t have to be that way; there is a method to set arbitrary baud rates, at least for some serial adapters.

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MQTT Broker

Jan 16, 2016. | By: Jerry

I am using Mosquitto, an open-source, multi-platform, broker and client. I chose it because it is easy to use on my platform of choice (Ubuntu), is being actively developed, and has a wide range of security options including encrypted connections, access control lists, and isolation of clients by group. Of course, there are a number of choices for a MQTT broker and any of them will work with T&L Nodes

Installing Mosquitto is easy, but configuration can be quite complex. The most difficult task is not the configuration itself, rather it is coming up with a plan to mange access and security. Developing that plan, and setting up a configuration to implement it, is more than I can cover here. You should read the manual page for mosquitto-conf, the well commented example file (/usr/share/doc/mosquitto/examples/mosquitto.conf.gz on Debian based systems), and probably seek out help from other sources.

In this post I cut through the complexity and present a simple setup that will work for the T&L Node and its Console. Of course the MQTT settings in the T&L Node Firmware must match these settings, so a matching example of an include/mqtt_config.h is also presented.

WARNING: This MQTT configuration is a totally unsecured configuration. Do not use it except as a test and learning exercise. Under no circumstances should you deploy this configuration.

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Comments and Feedback

Nov 3, 2015. | By: Jerry

In the footsteps of Eric Jones and Ivan Zuzak, I am using GitHub issues for feedback and comments.

Comments associated with posts will be shown on the post page. Feedback entered through the contact page will not be shown on this site, though it will be publicly viewable on GitHub.

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Getting Started

Oct 21, 2015. | By: Jerry

Well, not really. I’ve been working on a sensor node design most of 2015 and it is based on a long term desire to have small, low cost, wireless sensor nodes for my house and yard. This is just the start of documenting and sharing my work.

There are a lot of moving pieces in this project, so rather than adding it to one of my existing sites (dunmire.org or the newer RockingDLabs site) I think it deserves its own home.

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