Skip to content

Latest commit

 

History

History
70 lines (47 loc) · 2.63 KB

README.md

File metadata and controls

70 lines (47 loc) · 2.63 KB

Midi Accordion Project

Resources

Prototype Progress

Blink

Goal: Make sure Arduino functions

  • Open up the Arduino program
  • Select the right board, processor, and port
  • Upload it to the board

Success: make sure the light is flashing

Btn LED

Goal: Make sure we can connect to a sensor

  • Get a breadboard
  • Connect the Arduino to the power and ground rails
  • Connect power rail -> button, button -> 1K ohm resistor, 1K ohm resistor -> ground rail
  • Connect signal to arduino based on pin declared in config.h
  • Connect ground rail -> short end of LED, long end of LED -> 1k ohm resistor, 1k ohm resistor -> signal line, signal line -> arduino based on pin declared in config.h
  • Then program the arduino with the btn_led.ino

Success: Button press turns light on

Btn MIDI

Goal: Make sure we can play MIDI sounds by pushing a button

Success: Open garageband and press the button. You should now be able to hear a sound.

Opto

Goal: Make sure we can use opto interrupters as inputs. Success: Block space between opto-interrupters and hear different midi sounds.

Resistance Calculations

Here's the datasheet on the opto-interrupters: https://www.mouser.com/ProductDetail/Everlight/ITR-9608?qs=8cKuZ6Ok2lY35YbtvOHkMw%3D%3D

SO walkthrough: https://arduino.stackexchange.com/questions/76131/how-do-i-know-if-i-need-to-use-a-resistor-in-a-circuit

Important parts: Forward Voltage (Internal Voltage Drop): 1.2V typical 1.5V max Forward Current (Max Current) = 50mA = 0.05A

Ohm's Law is: V = IR Therefore R = V/I R = (input voltage - forward voltage)/(maxCurrent * limit%) The arduino will provide 5V. We want to downgrade the current by 25% so that it lasts longer. So the final formula is R = (5V - 1.5V)/(0.05A * 0.75) = 93.33 --> we need about 100ohm resistor 100ohm between the power and each side, then a 10K pull down resistor to GND between the emitter & the output wire