' LEDFLASH.BAS   program for Feb. 2003 "Silicon Chip" PICAXE-08 article
' Author - Stan. SWAN  => s.t.swan@massey.ac.nz  Ver 1.0  Jan. 2003
' Further comments/ASCII art  17th & 27th Sept 2003, but code unchanged
'
' It's traditional to test ones new microcontroller by easy LED flashing,
' -but this is such a trivial Picaxe task that hardly worth sweating !
' Further LEDs can be added at Pins 0,1 & 4 -extend code to suit. Light 
' chasers etc easily rolled up via small PAUSE delays between each LED
' NOTE - although initially added, dropping R's NOT NEEDED now since 
' Picaxe-08 has current limit of 25mA per pin ( rather bright for red)
' NB-white LEDs (due to phosphor coating on blue) may show "warm up' &
' afterglow lag & not true instant on/off. ~1ms interpreter overhead too
'
' Aside from "traffic light" simulations( c/w even a "cross now" buzzer ?)
' espec. useful extensions to explore relate to human flicker perception
' or battery life enhancement via tweaked mark/space ratios. Suit white LED
' front bike light or "lost in the bush" beacon, since-GRR!-classic LM3909 
' IC (used 1970s-mid '90s) LED flasher now discontinued. Winner (on TV too)
' Mikaela (7 yrs old!) did this for Aug.'03 "Science Fair"-New Plymouth, NZ 
' Such trials can be a REAL CHORE now LM3909 gone, needing 555 & parts box
' since 2 interelated formula need tweaking for 2 R's & large C involved.
' The parts count,size & maybe even cost is also  better with Picaxe-08s ! 
' Care- flash rates ~ 10Hz are annoying & may even cause epileptic fits
'--------------------------------------------------------------------------
'    	     - - - - - - - - - - -  -ve rail    		  
'   Piezo  	         L     L              NB-useful to include such 
'   and/or		 E     E	      "ASCII Art Schematic " 
'    LED		 D     D	      layouts for more complex
'  Pin|     _____    	 +     +	      designs, since it allows a	    
'   0 |     ___  | Pin 	 |     | Pin	      single file to contain all 
'    -+----    | |__2 ___|     |  1	      circuit info. Comments etc	    
'   |Picaxe|   |____________ __| -if          are NOT ported to the PICAXE           
'   |  08  |          		 used	      but ARE conveniently saved 
'    ------                            	      on your editing PC hard disk      
'	 |__ __4__|    (NB- pin 3 input only)                       
' |||		                        
'Usual 3 wire           + + + + + +  +ve supply        
'prog.input                           3 - 5V dc                 
'---------------------------------------------------------------------------
' Copy/paste program from web site => www.picaxe.orcon.net.nz/ledflash.bas 
' Lines preceeded by ', are documentation only & may be left out if typing
'---------------------------------------------------------------------------
ledflash:	' LED flash rate & mark/space experiment
high 2		' turn on output pin 2- LED lights up
 pause 5	' keep it on for 5 milliseconds
  low 2		' turn off pin 2 - LED goes out
 pause 50	' keep it off for 50 ms
goto ledflash	' repeat routine