13. Applications and Implications

This week we have to define the scope of our final project and develop a project plan.

What will it do?


The fishsitter will manage an aquarium. For this, for the first version fishsitter will be able to monitor the food cycle and send an alert if the aquarium temperature is not correct.

Who's done what beforehand?

Many projects was done about food feeding for cats, dogs, birds and fishs. I select my biggest inspirations. One thingiverse project, one research article and some projects of the previous fabacademies.

Fish feeder (thingiverse)

Research article

Previous fabacademies

What will you design?

I take much inspirations from other projects, but I redesign every thing to progress.

I will redesign the screw of my initial design, I will take the same mechanism then the AQUAFEED, he has the advantadge to be smaller than the infinite screw.

What materials and components will be used?


  • PLA for 3D printing parts (most of them)
  • PMMA for laser cutting



I didn't made the choice for know, but I want to use the bluetooth and http protocole to communicate with my fish sitter.

So I will try, to use the nrf52 to communicate with a local broadcaster (ESP32 or Raspberry pi). I don't know if the nrf52 will be able to manage all my inputs and outputs. If it's not, I will combine it with an attiny/atmega. Because he had 32 General purpose I/O and 4 channel PWM.

The nrf52 is quiet hard to find and the model that we have in the lab is quiet hard to use. So for the first version, I will use the Attiny84, because I'm familiar with it and I have enought pins for my needs.

Moreover, to have the network communication, I will add the BC-04 module.


For my final project, I will make an application to set the time period to give food for a fish.

If I have time, I will add this sensors:

  • Level food sensor : Proximity sensor, or ultrasonic sensor
  • Water temperature sensor


  • DC motor: Give food with the batcher
  • Led to have local alert

Where will it come from?

All components comes from the fablab, the DC motor comes from chinese vendor.

How much will they cost?

Less then 25€ to produce in the fablab.

What parts and systems will be made?

  • Food end alert mechanism
  • Food batcher mechanism
  • Communication and alerting

What processes will be used?

  • CNC milling : PCBs
  • Laser cutting: Box for electronics, global package
  • 3D printing

What questions need to be answered?

  • Can I use the BMD-300 chip for what I want ?
  • Can I be cheap less then 25€ ?
  • If it coast 25€, how much it will coast in production ?

How will it be evaluated?

For my final project, it could be evaluated, by this following terms:

  • Usabillity: Could it give food to a fish.
  • Bluetooth communication: Could It be actioned from a device.

Project planning

This is the planning that I maid for my final sprint of the fabacademy. I maid it by using Trello and Elegantt.