MECS

A python library for monitoring multiple sensor values on a MECS raspberry PI.

This is a draft tool at the moment, subject to change

Set up an sd-card

1. Flash raspberry pi OS lite to an sd-card (minimum 32GB).
2. Enable headless ssh access by adding a file named ssh into the boot partition

cd /path/to/boot/partition
touch ssh

3. Insert sd card into your raspberry pi

4. Log into the pi via ssh

HINT: If you have problems with this, try using putty to connect - this worked for us in the lab

Initialise the pi

1. Set the pi user password

passwd

1. Download the installation script

wget https://raw.githubusercontent.com/IESD/MECS/master/scripts/make_mecs.sh

1. Make the script executable

sudo chmod 777 make_mecs.sh

1. Execute the script

sudo ./make_mecs.sh

This will install a lot of stuff. You will see lots of output. Check for any errors.

Configuration

A configuration file is needed to use the system. A template is provided. By default, a copy of this will be placed in ~/.MECS/MECS.ini. For advanced usage, a configuration file can be specified as the first and only argument for all the following commands.

Usage

To get a readout of the current status

mecs-status

> *********************************************
> * MECS version: 0.1.0                       *
> *         conf: /home/graeme/.MECS/MECS.ini *
> *      UNIT_ID: unidentified                *
> *           DT: 2021-05-22 09:34:37 (UTC)   *
> *********************************************

To initialise the UNIT_ID to a user-specified value.

mecs-init
> Enter a new Unit ID (currently not set): MECS-0001

To begin a long-running monitoring process which saves data files every minute.

mecs-generate

mecs-generate is automatically enabled as a service (i.e. will always be running) To manage it, use systemctl

sudo systemctl stop mecs-generate
sudo systemctl start mecs-generate
sudo systemctl disable mecs-generate
sudo systemctl enable mecs-generate

To aggregate generated files into a single file for upload.

mecs-aggregate

This is automatically scheduled via cron so probably just leave it if you want to tweak it, edit the crontab for the pi user

crontab -e

To communicate with a server requires username, host and port to be set in configuration file.

these need to be set to a user and server that will receive the data via ssh

In order to register, you also need destination_root and archive_folder to be set in the configuration file.

the defaults are fine for this

Calling mecs-register will set up a public key on the server and create the necessary folders on the server and locally.

mecs-register

This won't work if you don't have a server configured and ready

To upload aggregated data to the server

mecs-upload

Again, this is already configured in cron

To work correctly, mecs-upload requires the same server parameters to be set as for mecs-register.