From 2967a3719fdcec430323c28e72098d333e6e299a Mon Sep 17 00:00:00 2001
From: Pieter du Preez <pdupreez@gmail.com>
Date: Sat, 17 Mar 2018 23:21:25 +0100
Subject: [PATCH] Added a Makefile that will produce ./lib/<MCU>/liblowpower.a
 files.

This patch attempts to achieve the following:

   * Supplies a Makefile for building a library per supported mcu.
   * Works around issue #14 in a single line inside the Makefile.
   * Fixes some warnings of unused variables for certain mcus
   * Removes the unnecessary inclusion of <Arduino.h>.
---
 .gitignore   |  1 +
 LowPower.cpp | 16 +++++++-------
 LowPower.h   |  2 --
 Makefile     | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 71 insertions(+), 10 deletions(-)
 create mode 100644 .gitignore
 create mode 100644 Makefile

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a65b417
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+lib
diff --git a/LowPower.cpp b/LowPower.cpp
index 5543bd6..bb1e88c 100644
--- a/LowPower.cpp
+++ b/LowPower.cpp
@@ -660,10 +660,10 @@ void	LowPowerClass::idle(period_t period, adc_t adc, timer5_t timer5,
 void	LowPowerClass::adcNoiseReduction(period_t period, adc_t adc, 
 										 timer2_t timer2)
 {
-	// Temporary clock source variable 
-	unsigned char clockSource = 0;
-	
 	#if !defined(__AVR_ATmega32U4__)
+	// Temporary clock source variable
+	unsigned char clockSource = 0;
+
 	if (timer2 == TIMER2_OFF)
 	{
 		if (TCCR2B & CS22) clockSource |= (1 << CS22);
@@ -804,10 +804,10 @@ void	LowPowerClass::powerDown(period_t period, adc_t adc, bod_t bod)
 void	LowPowerClass::powerSave(period_t period, adc_t adc, bod_t bod, 
 							     timer2_t timer2)
 {
-	// Temporary clock source variable 
+	#if !defined(__AVR_ATmega32U4__)
+	// Temporary clock source variable
 	unsigned char clockSource = 0;
 
-	#if !defined(__AVR_ATmega32U4__)
 	if (timer2 == TIMER2_OFF)
 	{
 		if (TCCR2B & CS22) clockSource |= (1 << CS22);
@@ -948,10 +948,10 @@ void	LowPowerClass::powerStandby(period_t period, adc_t adc, bod_t bod)
 void	LowPowerClass::powerExtStandby(period_t period, adc_t adc, bod_t bod, 
 									   timer2_t timer2)
 {
-	// Temporary clock source variable 
-	unsigned char clockSource = 0;
-	
 	#if !defined(__AVR_ATmega32U4__)
+	// Temporary clock source variable
+	unsigned char clockSource = 0;
+
 	if (timer2 == TIMER2_OFF)
 	{
 		if (TCCR2B & CS22) clockSource |= (1 << CS22);
diff --git a/LowPower.h b/LowPower.h
index 82f6f44..d52c0b8 100644
--- a/LowPower.h
+++ b/LowPower.h
@@ -1,8 +1,6 @@
 #ifndef LowPower_h
 #define LowPower_h
 
-#include "Arduino.h"
-
 enum period_t
 {
 	SLEEP_15MS,
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..4de724d
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,62 @@
+#   A Makefile that will produce a ./lib/<MCU>/liblowpower.a file per supported MCU.
+#   Copyright (C) 2018  Pieter du Preez <pdupreez@gmail.com>
+#
+#	This program is free software: you can redistribute it and/or modify
+#	it under the terms of the GNU General Public License as published by
+#	the Free Software Foundation, either version 3 of the License, or
+#	(at your option) any later version.
+#
+#	This program is distributed in the hope that it will be useful,
+#	but WITHOUT ANY WARRANTY; without even the implied warranty of
+#	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#	GNU General Public License for more details.
+#
+#	You should have received a copy of the GNU General Public License
+#	along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+# NOTE: All libs will be compiled with an 8MHz clock,
+#       unless CPU_FREQ is set at make-time.
+# eg. overriding all mcus to 16Mhz:
+#       CPU_FREQ=16000000L make clean all
+
+CPU_FREQ ?= 8000000L
+
+# NOTE: The atsamd21g18a is not supported by this Makefile.
+SUPPORTED_MCUS = \
+atmega168 \
+atmega328p \
+atmega32u4 \
+atmega2560 \
+atmega256rfr2
+
+# Default to the standard Linux tool paths.
+TOOLCHAIN_PATH ?= /usr/bin
+
+CC = $(abspath $(TOOLCHAIN_PATH))/avr-gcc
+CXX = $(abspath $(TOOLCHAIN_PATH))/avr-g++
+AR = $(abspath $(TOOLCHAIN_PATH))/avr-ar
+SIZE = $(abspath $(TOOLCHAIN_PATH))/avr-size
+
+TARGETS = $(addprefix lib/,$(addsuffix /liblowpower.a,$(SUPPORTED_MCUS)))
+SIZES = $(addsuffix _size,$(SUPPORTED_MCUS))
+
+# The following line is a work-around for issue #14:
+atmega168_DEFINES = -DSLEEP_MODE_EXT_STANDBY=SLEEP_MODE_STANDBY
+
+all: $(TARGETS)
+
+%_dir:
+	mkdir -p lib/$*
+
+lib/%/liblowpower.a: lib/%/LowPower.o
+	$(AR) -r $@ $<
+	$(MAKE) $*_size
+
+%_size: lib/%/liblowpower.a
+	$(SIZE) --format=avr --mcu=$* lib/$*/liblowpower.a
+
+lib/%/LowPower.o: LowPower.cpp LowPower.h %_dir
+	$(CXX) -c -std=c++11 -pedantic -fverbose-asm -Werror -Os -I$(AVR_INCLUDE) -DF_CPU=$(CPU_FREQ) $($*_DEFINES) -mmcu=$* -o $@ $<
+
+clean:
+	rm -rf lib