2016-09-24 01:25:54 +00:00
Tutorial 5b - indicator LED on IOE
==================================
This tutorial will show you how to add LEDs to an I/O expander.
It is assumed the reader is familiar with LEDs from tutorial_5a_LED_on_uC.md
and familiar with I/O expanders from tutorial_4c_split_keyboard_with_IOE.md.
Adding LEDs to the basic breadboard keyboard
--------------------------------------------
2016-09-28 19:56:10 +00:00
The breadboard keyboard modifies the split breadboard keyboard described in [tutorial_4c_split_keyboard_with_IOE.md ](tutorial_4c_split_keyboard_with_IOE.md )
2016-09-24 01:25:54 +00:00
Add components to the breadboard as shown in the picture.
The two clear plastic cylinders are red and yellow LEDs.
Each LED is in series with a 4.7k Ohm current limiting resistor.
2016-09-28 19:56:10 +00:00
LED anodes (the longer lead) are powered by pins GPA5 and GPB4.
2016-09-24 01:25:54 +00:00
LED cathodes (the shorter lead) are connected to a grounded terminal strip.
2016-09-28 19:56:10 +00:00
!["front" ](keybrd_5b_LED_on_IOE/front.JPG "front" )
!["back" ](keybrd_5b_LED_on_IOE/back.JPG "back" )
!["LEDs" ](keybrd_5b_LED_on_IOE/LEDs.JPG "LEDs" )
2016-09-24 01:25:54 +00:00
keybrd sketch with LEDs on IOE
------------------------------
The [keybrd_5b_LED_on_IOE.ino ](keybrd_5b_LED_on_IOE/keybrd_5b_LED_on_IOE.ino ) sketch will run on the above breadboard keyboard.
2016-10-30 08:30:13 +00:00
The sketch demonstrates:
2016-09-24 01:25:54 +00:00
* multiple layers
* split keyboard
* LED on controller
* LED on IOE write port
* LED on IOE read port