On Board LED Library Description

Author	:	Paul Carpenter
		PC Services
		www.pcserviceselectronics.co.uk
Version	:	V1.0.4
Updated	:	March 2023
Date	:	July 2018

Infineon XMC-for-Arduino LED Library, to assist in making board agnostic examples that will work the same across all boards. This file will be available in the library folder.

Often it is useful to have an example and have LED change state when things happen or errors occur, so to make this easier it is better to use on board LEDs that will always be there. Unfortunately if you are writing an example to use across many boards the XMC boards do not all work the same way. This library enables examples or applications to use the on board LEDs in the same way across all boards that any example supports. This is encapsulating the LED drive primarily for easier use of on board LEDs in examples that work on all or many of the boards.

Table of Contents

This document consists of these sections

• Hardware Differences
  • LEDs on Different Boards
• Requirements for Adding New Boards
• Known Limitations
• LED Library
  • Functions/Methods
• Examples
  • Simple LED

Hardware Differences between the boards

Unfortunately the on-board LEDs on the XMC range of boards work differently between different models. There is no consistent, on board LED driven by the same state to be ON across all models of board so we end up with

Board	Normal LEDs ON state	LED_BUILTIN Separate	LED_BUILTIN ON state
XMC1100 Boot Kit	Low	Yes	High
XMC1100 XMC2GO	High	No	High
XMC1100 XMC H Bridge2GO	High	No	High
XMC1300 Boot Kit	Low	No	Low
XMC1300 Sense2GO	Low	No	Low
XMC1400 Arduino Kit	Low	Yes	High
XMC4200 Platform2Go	High	No	High
XMC4400 Platform2Go	High	No	High
XMC4700 Relax Kit	High	No	High
XMC4700 Relax Kit Lite	High	No	High

** NOTE ** After Version 2.0 of XMC-for-Arduino, some boards were dropped (e.g. XMC1300 Sense2GO) they are still shown here for those using old versions of XMC-for-Arduino, and for history.

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LEDs on Different Boards

Matrix of available on board LED names or LED they map to, known currently.

LED Macro	XMC1100 Boot Kit	XMC1100 XMC2GO	XMC1100 HBRIDGE2GO	XMC1300 Boot Kit	XMC1300 Sense2GO	XMC1400 Arduino Kit	XMC4200 Platform2Go	XMC4400 Platform2Go	XMC4700 Relax Kit	XMC4700 Relax Kit Lite
LED_BUILTIN	Y	LED1	LED1	LED1	LED1	Y	LED1	LED1	LED1	LED1
LED1	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y
LED2	Y	Y	Y	Y	Y	Y	-	Y	Y	Y
LED3	Y	-	-	Y	Y	-	-	-	-	-
LED4	Y	-	-	Y	-	-	-	-	-	-
LED5	Y	-	-	Y	-	-	-	-	-	-
LED6	Y	-	-	Y	-	-	-	-	-	-

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Requirements for Adding New Boards

Every board has to have its own pins_arduino.h, then so that this Library can distinguish the operation this file must include a #define macro based on XMC_LED_ON as below -

/* On board LED is ON when digital output is 1, HIGH, TRUE, ON */
#define  XMC_LED_ON 1

OR

/* On board LED is ON when digital output is 0, LOW, False, OFF */
#define  XMC_LED_ON 0

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Known Limitations

This is meant for controlling hardware on board LEDs on the XMC1 and XMC4 series, if your additional LEDs operate the same way as the on board you can use the same functions but this may not be portable when adding your hardware to other boards.

See LEDs on Different Boards

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LED Library

All functions have a Arduino Pin reference passed in or a macro that defines it e.g. LED1 or LED2.

Note at present all boards have 2 LEDs as a minimum some have 3 or 6 LEDs. Obviously only reference LEDs that actually exist for the boards are supported.

This library uses NO RAM storage it is mainly software encapsulation/wrappers to other functions.

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Functions/Methods

Function		Description
Add	-	Configure an On board LED as digital output
On	-	Turn on board LED ON
Off	-	Turn on board LED OFF
Toggle	-	Toggle on board LED (if was off now on, if was on now off)

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Class Instantiation and Initialisation

In user application include the LED.h file, instantiate the class, in setup() later add the LEDs to the class just initialises them to digital outputs.

/* For on board LEDs */
#include <LED.h>

/* Create an LED object */
LED Led;

Later in setup()

void setup( )
{
Led.Add( LED1 );               // Add LED (configure for output)
...

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Examples

This is here for completeness of Arduino IDE library structure.

Simple LED

This example works on all currently known boards simply

• In setup() sets up two LEDs
• In loop()
  • Waits one second
  • Toggles LED1
  • Turns Off LED2

If a board like XMC4200 Platform2Go with only ONE LED is in use only LED1 function is used

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