IFD Project: "The Wor Machine"

This repository contains the necessary bits of code and schematics to reproduce our group's project for the "IFD" (Practical Informatics) class. Our group's subject is a counter for the number of people present in a store or place. It uses Little's Law to determine the average time spent by people in the shop; the necessary data is sent through MQTT to do the calculations and have a means of permanent memory. The device also measures the temperature and buzzes if it is abnormally high.

The materials needed for it is:

• 1 ATMega2560, equipped with an esp01_1m-like chip (we used a WeMOS card for that matter)
• 2 light sensors
• 2 laser emitters
• 1 temperature sensor
• 1 buzzer
• 1 button

Installation

First, download this repository and set initially set up the credentials:

git clone https://github.com/adri326/ifd-project
cd ifd-project
cp esp/src/credentials.cpp.sample esp/src/credentials.cpp
# You will need to edit esp/src/credentials.cpp with the correct settings

Building and flashing

You will either need PIO installed as a VSCode extension or as a standalone extension.

With the PIO VSCode extension

If you use the former, then you will need to add both ifd-project and ifd-project/esp as PIO projects. Run "build" on both of them.

To flash the ESP build, set the bridges on the WeMos to 00001110 (5, 6 and 7 high). Connect the card via usb to your computer, hope that it connected well and run "Upload".

To flash the ATMega build, set the bridges on the WeMos to 00110000 (1, 2, 3 and 4 high). Connect the card via usb to your computer, hope that it connected well (it usually doesn't, try different cables) and run "Upload".

With a standalone installation of PIO

Go to the ifd-project/esp (cd esp/) directory and run pio run. Set the bridges to 00001100, connect the card via usb to your computer and run pio run -t upload.

Go to the ifd-project (cd ..) directory and run pio run. Set the bridges to 11110000, connect the card via usb to your computer and run pio run -t upload.

Node-Red

This project includes a Node-Red flow, located at flows_anarchy.json. You should copy that file into your node-red storage folder.

You can then run Node-Red using npm:

npm i
npm run start

The GUI should then be available at http://localhost:1880/ui/.

API

The card communicates via MQTT to a broker; its messages are in the following format:

(* This is EBNF. Check out https://fr.wikipedia.org/wiki/Extended_Backus-Naur_Form for more information! *)
msg = "[", command, [{":", value}], "]";
any_character = ? any character, bar ":" and "]" ?;
uppercase = ? uppercase letters ?;
command = {uppercase};
value = {any_character};

The commands used are the following:

• The card sends the [QUERY] message to the TOPIC_OUT channel; you may answer to such a message by sending it back the number of people using the SET message (see below)
• The card periodically sends the UPDATE command, with as parameters:
  • The current number of people in the room
  • The current arrival rate in humans per minute
  • The average number of people in the room
  • The average time spent in the room in seconds (eg. [UPDATE:3:2.0:2.5:47] for 3 people in the room, 2.0 people coming in per minute, 2.5 people in the room in average and 47 seconds spent in average in the room)
• The cards may receive a SET command, with as parameter the number of people that the card should think are in the room (eg. [SET:3] to set the counter to 3)