Smart Desk Lamp

Summary

For this project I:

  1. Designed the parts of the Lamp in Fusion 360.
  2. Designed the schematics for my main board and my sensor boards in Eagle.
  3. Created capacitive electrodes for Capacitive Buttons (touchless buttons)
  4. - If you are interested please learn the difference between a mutual capacitive sensor and a self-capacitive sensor
  5. Programmed in C both the main board and the sensor boards.
  6. Connected the sensors in a asyncronous network to control light intensity.
  7. Machined the wood in the Shopbot.

Design objective

Two main trends inspired me to design my final project proposal. 1. The open office trend which companies have adopted have created problems with privacy. 2. IoT is becoming more and more important but is not only about what we measure but what do we do with the things that we measure.

My ideal SmartLamp will let you control the light intensity, let you know the conditions of your work envieronment and give external signals when you do not want to be disturbed. This first version of my Smart Lamp will only implement the first and third function, a future iteration will cover the temperature sensor and the external network.

Design on Fusion 360

I have become very familiar with Fusion 360. I discovered the easy that is to simulate, test and even assemble your model, test it and make changes in one applicatio. Fusion 360 is easy when you get used to its platform, but is important to have some desing workflow, otherwise if you do not follow a structured workflow it can become almost imposible to later adjust your design for little things like the thick of your material and other things like that.

To design my lamp I followed a Top Down Strategy, you can find a nice tutorial in the link and also in Fusion 360 Official YouTube page there are a lot of good tutorials.

Finally, instead of having a sensor module, I decide to include the boards inside the lamp. My design will consist of:

Electronics

  1. Main Board: this board will control the light intensity of the lamp and will turn on and off the whole lamp. It will also control the "Do not distrub" LED.
  2. 40 Sensor boards: 40 sensors board whith a capacitive button that will control each of the LEDs of the lamp.

Body of the lamp

  1. Wood sheets: I am thinking that Oak will be the best wood to use because of its properties.
  2. Metal tube: the tube will help the lamp to have some movement, it will keep in position by friction only.

Capacitive Sensor

To get the correct capacitive sensor can be very tricky. Eagle does not offer a capacitive electrode library (Altium has one if you are willing to pay).

If you are in your path to build a capacitive sensor, I strongly recommend that you read this Sensor Tutorial. Basically there are two types of sensors:

  1. Self-capacitive sensor: based on Neil's Step Load Board you can build this type of sensor. The good thing is that is preety easy to build. The bad thing is that the sensor depends on the envieronment circunstances, could give you false positives.
  2. Mutual-capacitive sensor: based on Neil's Trasmit-Receive model. This model is more reliable. The bad thing is that the electrodes are very difficult to design correctly.

This week I did my first try to try to sense throug acrylic, I only manage to see a difference of 10% in the signal. I need to try with other designs.

First try

This week I tried three types of sensors, but non of them worked as expected. I am going to try to make them a little bit bigger.

Second Try