About

This little script serves my particular need to track a DECT 440's humidity and temperature in a room with a dehumidifier connected to a DECT 200, while also collecting power consumption.

Unfortunately, Fritz!DECT 440 does not yet offer (daily) push mails that would let me collect its data like I am used to with Fritz!DECT 200 devices sending temperature and Watt data.

Using FritzBox' HTTP-AHA-Interface, fritzdect-aha-nodejs, Nodemailer and a Raspberry PI with a cronjob set up, this simple script accumulates measured values from DECT 440 and DECT 200 in a CSV file and sends it out via email every evening.

Prerequisites

• Raspi (or any other Linux based machine running 24/7
• Node.js v20.6.0+ due to its native support for loading .env files
• regular SMTP email account

To install Node.js on Raspi, this line did the job for me (source).

curl -fsSL https://deb.nodesource.com/setup_lts.x | sudo -E bash - && sudo apt-get install -y nodejs

Setup

1. git clone this repo and npm i
2. Create .env from example.env template and fill in the correct values where AID_[DECT200|DECT440] are your DECT's Actuator IDs
3. Modify path in run.sh

Test-run directly

node --env-file=.env index.js

Test-run via shell script

./run.sh

The shell script should have the executable bit checked out. If not, chmod u+x run.sh to add it.

Setup crontab

$ crontab -e, add and modify this line

15,30,45,0 * * * * /home/USER/PATH/fritz-dect-statistics/run.sh >> /home/USER/PATH/fritz-dect-statistics/run.log 2>&1`

This runs the script every hour at 15, 30, 45 and 0 minutes (just like Fritz!Box' daily push mail CSVs).

This crontab setup should survive reboots.

Good to know

• The script accumulates data within statistics.csv, adding a line every 15 minutes.
• statistics.csv is checked in empty (with header only), then added to .gitignore, then removed from Git tracking via git update-index --assume-unchanged statistics.csv. To temporarily track it again to commit changes use git update-index --no-assume-unchanged statistics.csv
• Email is sent between 23:31 and 23:59, which means the crontab must be configured to run within this time of the day, if you want to receive a daily email. Furthermore it simply attaches the current CSV file, which is growing constantly. Maybe improve this later.