Final project proposal
In addition to our first week assignment (building a website and getting familiar with git), we had to start thinking of a possible final project. I'm not yet completely decided but I would like to build something for the internet of things (IoT), maybe a weather station that would send data to my smartphone using Bluetooth Low Energer (BLE) or wifi. I don't know if it is possible to use module such as the RFDuino that combine BLE and an arduino-like microcontroller. In case it's not, I will use the FabDuino and a wifi or BLE module. If those modules are not allowed, I may have to design my own but then it becomes complicated because of high frequencies, antenna, etc...
I may add some LCD display on the object itself and I want to design different cases that I will 3dprint.
Materials and components
- 220V-5V power supply.
- dc-dc converterr 5V - 3.3V
- RGB LEDs, because they are nice
- Fabduino
- Pressure sensor
- Temperature sensor
- ...
CAD, 3d printing and laser cutting
I will need to design a case for the weather station. I'm not yet decided on which CAD software I will use. For now, I like openSCAD but I invested some time in Autodesk Fusion 360 and I find the possibility to combine mechanical modeling tools with free form sculing tools quite appealing. I will probably make two versions of the case: the first one using 3d printing to create something curvy and nice and a second version more squared using laser cutting of acrylic sheet. The case in acrylic will be transparent which is good to me because I always want to know what's in the box.
Electronics design and production
I will make a FabDuino and probably adapt the design to integrate the bluetooth module (see below) on the board.
Networking and communication: Bluetooth Low Energy
I already have some experience with the RFDuino but I understand that it is too integrated for a FabAcademy final project. I recently bought an Adafruit Bluefruit LE SPI friend (SPI stands for Serial Peripheral Interface). I want to try it with first an Arduino Uno then the Fabduino, once I have made one (still waiting for electronic components). It uses four pins (SCK, MISO, MOSI, and CS/SSEL) plus a 5th GPIO pin for interrupts:
- SCK is the serial clock pin to be connected to SCK (to pin 13 on the Arduino Uno)
- MISO stands for Master In Slave Out for the communication from the device to the microcontroller (to pin 12 on the Arduino Uno)
- MOSI stands for Master Out Slave In for the communication from the microcontroller to the device (to pin 11 on the Arduino Uno
- CS stands for Chip Select and is used to indicate that the SPI device is in use (to pin 10 on the Arduino Uno)
It has a 3.3V on-board voltage regulation and can thus be powered safely with 5V. Te be continued...
Application programming
I will use a priori the Apache Cordova environment to develop an android/ios app using html/css and javascript. I already an apple developper account to deploy apps on my iphone and on the App Store. Cordova Plugins exist to enable serial communication over bluetooth between the app and the device.