First Try: The hand soildered board

My two main goals with this part of the process were 

  1. Making the button a stand alone object
  2. Being able to release the model so other can use the basic structure of it, specially into the Sensor Library

With this in mind I started this project by transferring the code into an ATTINY85 and selecting the output to be a LED.

To install the code into the ATTINY85 I used an Arduino Uno as the loader. The process of doing this is pretty straight forward, both with regards to the code and the circuit setup. Since this code is very simple it doesn't need much tryout but if it needed to be revised (which I did only because I worked with a flawed ATTINY for about an hour) its better to have two boards, one that will test the sketch and another one that will load the code into the ATTINY.

Once the ATTINY85 was ready I set it up on a Breadboard for tryout with two 3V batteries.

At this point I realized there were two main components I needed to pay attention to in this prototype: the battery package and a switch.

As the enclosure I designed a holder to be laser cut and placed with standoffs above the board. This design includes a switch and the breadboard design considers a battery package for two 3V cell batteries. Due to time constrains and the battery packages I tried being horribly faulty I ended up creating my own "package" for the batteries, so this is something that still needs to be figured out so that it is included in the BOM.

Part of the idea of this board was that it could be placed into a ballon, closed in there and then just squish the ballon to get the signal. But this was not happening, because the sensor checks for pressure diference and by being withing the fluid it cannot register a change in the pressure since it is only displacing withing its atmosphere

So to hold the "guts" of the button I laser cutted a paper dodecahedron. This is not the best solution as the switch gets trapped inside of it. So if the button will be used in this application the board and the enclosure need to be design with the light diffuser.

Moving forward with this project this is the checklist:

  • Imagine other applications for this prototype other than a very weird flashlight
  • Create a board in which the output of the sensor can be changed
  • Also the communication of the sensor can be augmented, through giving the board a way of having a wifi/bluetooth integration, as well as communicating with another microcontroller or having a Serial communication port.
  • Have a 3D library of the components so new enclosures can be designed for different applications
  • Solving how power should be provided for the different communication solutions (wifi, serial, bluetooth)

In order to replicate this prototype the BOM would be:

  • Enema Bulb
  • MPX5010 case 867B-04
  • ATTINY85
  • 220 resistor
  • White LED
  • 2 3V cell batteries
  • Acrylic (or other material for enclosure) and standoffs

The schematics and code live here:

https://github.com/RSofiaC/pressureControl/tree/master/ATTINY85