Assignment 15


Applications and Implications


Propose a final project that integrates a range of units covered. Projects can be separate or joint, but need to show individual mastery of the skills. Where possible, you should make rather than buy the parts of your project.

Learning outcomes:

Have you answered this questions:


The answers to the question above will become BOM, or Bill of Materials.



Answering the questions ...

What will it do?

The proposed final project is a set of dorm-room lamps (or whatever illuminated environment) that will network among them so you can modify all or each of the lamps in the set through any of the lamps on the set. Other desirable feature of the set is that all the user interactions with the lamp set will be through a touchpad interface.

Who has done what beforehand?

The project can be devided in the next modules that can be approached independently:

  • Output: A microcontroller handling the lamp's light intensity. Yet this part of the project is the one with the lower priority, I haven't defined yet if its going to be a bulb (I need to verify if I have some kind of AC dimmer at hand, time factor) or if its going to be a LED lamp (I need to find a nice LED(s) that's enough to illuminate properly), in the quest for efficiency and simplicity of development I think the logical is to aim for LEDs.
  • Input: A touch interface to control all the functions in the lamp. Regarding this area I've found to main reference projects: Matt Blackshaw's input devices assignment and Matt Keeter's multi-touch device, both appeared in our "Input Devices" class.
  • Networking: The lamps will communicate among them through a network. At first I thought of using some kind of mesh network over a Bluetooth interface, but looking for alternatives I found a couple of projects based on the ESP8266 module that might be suitable. Here's a link. Anyways, this part of the project needs more research.

    I friend recommended me to look at this Nrf24l01 module, which has a mesh networking library writen to Arduino, thus compatible with our AVR menu.

  • Structure: The idea is that the lamps will be laser cutted or CNC milled. This part is almost straight forward, so I'm not using project references to this part of the work. Maybe I'll include some servo moved parts on the lamps ... thinking of maybe move away the parts of the lamp close to the touch control panel to leave more room to manіpulate it.

What materials and components will be required?

So, I'll start checking each of the project's parts to define which microcontroller I need.

First, to communicate the lamps I'll use the Nrf24L01 module, whatever way needed, in the worst case escenario I'll still be able to communicate at least 2 lamps.. This module uses 6 pins: GND, VCC (3.3V), SCK (goes to Arduino pin 13), MOSI (goes to Arduino pin 11), MISO (goes to Arduino pin 12), CE (Chip Enable, goes to Arduino pin 7), CSN (SPI Chip Select, goes to Arduino pin 8) and IRQ. More details in this link.

To move some part of the lamp I'll need 1 servo motor, which needs only one PWM pin.

To handle the light intensity I'll need other PWM pin.

To read the touch control I need one pin per button (as described in Matt Blackshaw's input devices assignment). I plan to have one long column to set the light intensity and two(?) touch buttons to modify behaviour (controlling through the mesh network). Those would be at least 3 more pins (VERIFY IF SOME SPECIAL KIND IS REQUIRED). Finally I simplified the networking scheme, there will be only two lamps so the lamp's interface will consist of two touchpad buttons, one to control the light intensity and the second to transmit the commands to the other lamp.

Where will they come from?

Most of the electronics I'll use are part of the Fab Academy inventory, except for the nRF24l01 module (6USD on a local reseller). I'll also need wooden boards to mill the lamp and acrilic to cover the electronics, all of the available on neighbour stores.

How much will it cost?

The costs of the materials needed to be bought are:

  • nRF24l01 module: 6USD on a local reseller.
  • 5mm thick acrilic: about 60USD per board (60x90cm), but I'm recycling it from other project from the Fab Lab
  • Wooden board: 2"x6"x3mt board, 10USD
  • LED lamps: I'm building a LED arrange from 10cent highpower LEDs and a protoboard, the total expense of this part goes up to around 2USD.

What parts and systems will be made?

The lamp structure will be milled on wood and I'll laser cut a cover. On the electronics side, I'm building the light intensity control system and the touchpad system. The networking system works over a library for the nRF24l01 module.

What processes will be used?

The processes are: laser cutting, CNC milling, electronics design and embeded programming.

What tasks need to be completed?

As I started working on the project I realzed that most of the work depends on the electronics design, so I started by gathering references and testing the different parts to then integrate all the hardware on the electronics (I'm leaving the programming to the end, but being sure that I have all I need to make the board work). After the PCB design I need to manufacture it to verify it and then, with this confirmed, work on the lamps CAD model to mill.

What questions need to be answered?

Why I'm doing this? What is life about? How will I use all this to grow as a person? It is raining outѕide?

What is the schedule?

My original plan was:

  • Test the different electronic parts independently to verify factibility and requirements
  • Mockup the lamp (at this point we made the June 17th's
  • presentations)
  • Design the PCB
  • Buy all the materials
  • Build the PCB (got delayed because I chose a wrong 32pin mega328 board which was a lot tinier that the one we have, and spent many days on trying to mill that PCB to only after realizing that the microcontroller didn't fit)
  • Build the lamp
  • Mount and test the fitting
  • Redesign (today July 6th I'm at this point)
  • Build final version
  • Program
  • Hero shot

How will it be evaluated?

The project's goal is to have 2 lamps that can:

  • 1. Modify the light's intensity
  • 2. Transmit the light intensity instruction to a remote lamp.