Hobbyist hardware for sensors, automation, smart devices, secure computing

published Oct 02, 2016 02:20   by admin ( last modified Oct 14, 2016 03:00 )

As a hobbyist as you are thinking of little projects to make, you start thinking about what is the right tool for the job: A Raspberry Pi, an Arduino, a Teensy, some kind of dedicated module?

I am not that experienced a hobbyist yet, but below I have tried to break down into four categories what categories my project plans or occasional actual project, tend to to end up in:

  • Wireless sensor
  • Smart device
  • Home automation
  • Secure computing

Wireless sensor

Characteristics:

  • Should last on a battery for at least a year
  • Should communicate wirelessly

Solutions:

  • Arduino-compatible low power chip with lots of power saving features switched on, paired with Bluetooth LE
  • TI's SensorTag, can communicate via Bluetooth LE, 6LoWPAN or ZigBee

Examples:

  • A humidity sensor for keeping indoor air from being to dry
  • Sensor to control a fan in a bathroom

Smart device

Characteristics:

  • Can measure things, move things (actuators) and interact via a display with a user

Solutions:

  • Use an Android phone, it has built in Bluetooth, Wi-Fi, 3G, USB and a battery backup. Takes a whole lot of work to get that with discrete parts. Sometimes the headphone output can control a servo. otherwise put an amplifier there or use an USB OTG cable and firmata.

Examples:

  • A bitcoin triggered lock box

Home automation

Characteristics:

  • Can measure, control and communicate to the Internet

Solutions:

  • Use a laptop connected with an Arduino or similar connected to it via USB. The laptop has built in battery backup and Internet connectivity + keyboard and a display
  • Use an Android phone

Examples:

  • Automation of watering house plants

Secure computing

Characteristics:

  • Encrypt stuff, sign stuff, safeguard stuff

Solutions

  • Use something like a Teensy3.5/3.6 or similar that has a cryptographic co-processor. An Arduino might suffice if you're doing simple things such as just inputting or outputting characters

What about the Raspberry Pi?

Interestingly enough the Raspberry Pi never featured in this when I started thinking about it. Capricious shutdowns may corrupt it's SD card which could take the system out of commission. It takes a number of additional components to make it have a rechargeable battery and a display. There are attempts to run Pis on their bare metal but it's hard to get good documentation on how the hardware works on that level apparently. It seems to work well for home entertainment though.