Add comments

Add comments in makefile. I had to work a bit in order to remember how
things work; help future me by not having to redo this work again.

Clean a bit the .ino header. This was all based on jjrobots work, but it
has been all changed since.

arduino/Makefile

@@ -1,12 +1,24 @@
+# Board setup
 BOARD_TAG    = nano
 BOARD_SUB    = atmega328
 
+# Use 'do_upload' target to upload software to arduino's flash.
+# You need to set this variable correctly.
+MONITOR_PORT ?= /dev/ttyUSB0
+
+# LCD pins/pcb socket have been prepared, but software is lagging behind.
+# Disabling until the situation changes.
 #ARDUINO_LIBS = LiquidCrystal
+
+# Libs for handling the Nema motor and the trigger swtiches.
 ARDUINO_LIBS = StepperDriver Switch
 
+# Points to submodule
 ARDMK_DIR:=$(PWD)/Arduino-Makefile
 
-ARDUINO_DIR := $(HOME)/arduino/arduino-1.8.2
+# You may need to change this, depending on your local setup.
+ARDUINO_DIR := $(HOME)/arduino/arduino-1.8.5
+
 USER_LIB_PATH := $(PWD)
 
 include $(ARDMK_DIR)/Arduino.mk

arduino/startracker.ino

@@ -1,4 +1,15 @@
 // -*- mode: c++; -*-
+//
+// Startracker drives a NEMA17 for compensating the earth rotation
+// during long exposure photography.  Original code based on JjRobots
+// (see below), but everything has been rewritten since the begining
+// of this project.
+//
+// This was tested with an arduino nano.
+// Board wiring (and PCB) are available along with this code.
+// See https://framagit.org/marc/startracker
+//
+// Initial header :
 // STARTRACKER MOTOR CONTROL: STEPPER MOTOR CONTROL FOR JJROBOTS POV DISPLAY
 // This code is designed for JJROBOTS arDusplay Stepper Motor Control board
 // Author: JJROBOTS.COM (Jose Julio & Juan Pedro)