Class 5

Key : 🔹 discussion     🔸 lecture        demo/activity      🍕 lunch 

 Prototype building

🍕 lunch

 Soldering demo and safety

 RGB LED

  • review of digital and analog input/output

 Prototype building

  • write down 3 questions/theories your prototype is addressing and post on your student page along with pictures of prototype and process.

Three Circuits Demoed in Class

1) Flex Sensor Range to RGB LED

2) Capacitive Sensing with Mpr121 Breakout board

3) Capacitive Sensing with Arduino Library

 

H.W. finish 1st prototype per requirements 

 

1st Prototype Requirements

This prototype is addressing shape and size of device and interaction of working circuit. 

On your documentation page: 

  • write down 3 questions/theories your prototype is addressing and post on your student page along with pictures of prototype and process.

Circuit that includes input and output.

  • circuit is off of breadboard and soldered or sewn together
  • output is LED in place of final tech (sound, USB mouse, IR)
  • input is either a digital or analog input as discussed and demoed in class
  • wired circuit – you can omit conductive thread or fabric at this stage for traces if you choose. Any soft switches or sensors must use thread or fabric however.
  • strain relief: soldered and sewn points are weak and will break over time. Strain relief is a must for a circuit off the body so it is even more relevant when you put it on the body! 
  • strain relief: traces need to bend and stretch with fabric. Otherwise, the circuit will break at its weakest point to accommodate which is usually soldered points. Build slack into the traces to accommodate for movement.

Physical build of prototype(s). This can be one or two shapes and sizes you need to test with your user.

  • circuit is on fabric ready to be user tested
  • edges are unfinished
  • use markers and pens to take notes on prototype during user testing

When transferring a circuit to fabric there are some things to take into account. Follow this tutorial on how to successfully transfer from breadboard/alligator leads to fabric.

Bring your computer but do not rely on it to power your circuit to test. Use a battery to power your circuit with an LED as output in case you can not use your computer to look at sensor values. I also recommend bringing the longest USB cable you can find to connect the microcontroller to the computer. This will give you more space to work with if you can test your device on the participant while it’s connected to the computer.