Paraphraser

Tutorial: Enabling authentication in InfluxDB

Assumptions:

• you are running SensorsIot/IOTstack with InfluxDB as one of the containers
• you want to enable authentication for your InfluxDB databases.

Note: This tutorial is specific to SensorsIot/IOTstack.

Definition:

Paraphraser

Tutorial: Enabling UDP support in InfluxDB

Assumptions:

• you are running SensorsIot/IOTstack with InfluxDB as one of the containers
• you want to enable UDP support
• your goal is to log traffic arriving on UDP port 8086 into an InfluxDB database named "udp".

This tutorial is specific to SensorsIot/IOTstack. You're on your own if you "get creative" and choose different ports or database names.

Paraphraser

Tutorial: MQTT and the retain flag

Assumptions and setup

This tutorial assumes:

• a single computer (like a Raspberry Pi)
• MQTT broker (like Mosquitto) running
• the mosquitto_pub and mosquitto_sub commands are available.

Paraphraser

Calculating barometric pressure trend

This gist is a response to a Discord question. It explains my approach to deciding whether barometric pressure is rising, falling or remaining steady.

I do the trend calculation in Arduino (ESP8266) code. I tried to mimic the idea of setting the reference needle on a real barometer, waiting an hour, then seeing which way the pressure needle had moved with respect to the reference. The wrinkle is that "the last hour" is a moving window that updates every 10 minutes.

The BMP085 sensor is polled every 10 minutes. Until there are six observations (eg after a reboot) the code returns "training".

After that, the code does a least-squares regression on the last six observations (ie the last hour of data) to find the linear equation of best fit. In effect, the algorithm assumes that knowing the time (independent variable on the X axis) at some point in the past hour would permit the pressure at that time (dependent variable on the Y axis) to be estimated with some degree of

Paraphraser

IOTstack Recipe: Node-RED themes

This gist explains how to activate a theme for the Node-RED graphical user interface under IOTstack.

Reference

• Node-RED themes collection

Step 1: install the themes package

Paraphraser

Recipe: from MQTT to InfluxDB via Node-RED

• 2024-05-16 adds case study explaining how to extract values from topic strings, and how to specify the measurement name in the message payload provided to the "influxdb out" node.
• 2023-12-02 revise graphics to correspond with "influxdb out" node, and explain the pros and cons of InfluxDB 1.8 vs InfluxDB 2.

Introduction

Getting data produced by IoT sensors into a database is practically a mandatory step before effective visualisation (eg dashboards).

This recipe shows you how to get an MQTT payload into an InfluxDB database using three Node-RED nodes. It makes the following assumptions:

Paraphraser

Configuring Raspbian to use local time-servers

The case for using local time-servers

Out of the box, Raspbian gets its time from NTP servers in the debian.pool.ntp.org domain. You can confirm this via:

$ timedatectl show-timesync
...
ServerName=0.debian.pool.ntp.org

Paraphraser

Keybase proof

I hereby claim:

• I am paraphraser on github.
• I am paraphraser (https://keybase.io/paraphraser) on keybase.
• I have a public key ASAEuq9mHBtAWcvqsEvFAC-CtHGqjRDtQU3Ht7YY0MrSJQo

To claim this, I am signing this object: