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keybrd/tutorials/tutorial_5b_LED_on_IOE.md

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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
--------------------------------------------
The breadboard keyboard modifies the basic breadboard keyboard described in [tutorial_1_breadboard_keyboard.md](tutorial_1_breadboard_keyboard.md)
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.
LED anodes (the longer lead) are powered by pins GPA6 and GPB6.
LED cathodes (the shorter lead) are connected to a grounded terminal strip.
!["LEDs"](keybrd_5_LEDs/LEDs_back.JPG "LEDs")
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.
The sketch features:
* multiple layers
* split keyboard
* LED on controller
* LED on IOE write port
* LED on IOE read port