'DATA08M.BAS = NTC temp.datalogger-Picaxe-08M version Ver 1.0  30/08/04   Stan. SWAN
'Program a "hi res" enhancement of lo res datalog8.bas shown Sept.'03 SiChip article 
'NB-this further enhances orig.08 version with 08M "SERTXD" cmd feeding serial data  
'out via normal 3 wire progr.lead @ 4800bps & displays via editor F8 inbuilt terminal
'===================================================================================
'When "08M" powered up,any prior stored EEPROM values sent SERTXD pin 0 serial data 
'-also suit 4800bps display via any term. program -LCD,F8,StampPlot- or.csv Excel too.
'NB-Gives you 30secs to turn unit OFF before fresh storage begins & thus progressively
'wiping existing values ! For security however this data can't easily be bulk erased
'***BUT CARE - BE PROMPT ! REPROGRAMMING/RELOADING  "08M" TOTALLY WIPES DATA TOO ****.
'As set up logs NTC temp every 60 secs for ~2 hrs.Alter WAIT value (or SLEEP)to suit?
'-------------------------------------------------------------------------------------
'PICAXE08M has hi-res data values 0-255(via "readadc" command),but also READTEMP for
'direct DS18B20 Celsius readings! Both 08 & 08M values stored in program space. Care !
'If power saving needed use SLEEP instead of WAIT ex. 26x2.3secs ~1min delay (+/- 1% )
'Alter to suit.Ex. Sleep 391 =128 x 1/4 hr =32 hrs.Some interpreter o'head/drift noted
'128 readings,so @ 1/min ~2 hrs, /5 min ~10 hrs, /30 min ~2.5 days,& /60 min ~5 days  
'NB- sensor thermal lag means there's little point sampling faster than every minute ! 
'Solderless "PICNIK" mini breadboard setup pix => www.picaxe.orcon.net.nz/pcxs08m.jpg 
'Program hosted=> www.picaxe.orcon.net.nz/data08m.bas.  ASCII art schematic below 
'-------------------------------------------------------------------------------------
' SERTXD					 Typical temp. readings/readadc values
' & piezo              - - - - - -ve rail	            0 Celsius    11	
'   Ch.0     _____   Ch. |     |			    4            21
'    - |    ___  |    2 LED   47k			    8            32
'    ------    | |_______|     |			   12            43
'   |Picaxe|   |_______________|                   	   16            53
'   | 08M  |     Ch.1 ADC      |			   20            64
'    ------                  100k                  	   24            75
'    +          	     NTC                  	   28            86 etc 
'|||	                                3-5 V
'Usual 3 wire         + + + + + +  +ve supply       NOTE - Temp values approximate
'prog.input                                         & may need calibration your NTC
'---------------------------------------------------------------------------------------
					'READ/PLAYBACK ROUTINE 
pause 100				'needed to wake up sertxd & avoid initial junk?
sertxd("   PICAXE-08M NTC Temp.Datalogger  ")		' Title header 
for b0=0 to 127				'stored data values readout to terminal or LCD
read b0,b1				'polls & reads out stored EEPROM values ( .csv)
sertxd (#b0,44,#b1,"  ")		'Values @ prog.pin,+ ASCII comma(44) for Excel .csv
high 2					'LED at output 2 on to confirm data readout 
next b0					'read next stored EEPROM value as SERTXD serial out 
wait 30					'30 secs "reading" delay -modify if too short etc
low 2					'LED off shows reading over, & new data run starting
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					'WRITE/DATA LOGGING ROUTINE
for b0= 0 to 127			'begin 128 data readings @ time set by SLEEP/WAIT
sound 0,(75,10)		    		'Beep to alert data logging commencing
pulsout 2,500				'brief flash from pin 2 LED indicates datalogging
readadc 1,b1				'Hi Res (8 bit) read NTC at Pin 1 Voltage divider 
sertxd ("  ")				'gap as usual 10=CR,12=FF(=cls),13=LF nogo with F8?
sertxd(#b0,44,#b1)			'Now allows data display (via F8 ?) as gathered too!
write b0,b1 				'sequentially write values to 08M EEPROM locations
wait 60 				'Checks every 60 secs -alter to suit or use SLEEP etc	
next b0					'Gathering automatically stops after 128 samples
high 4					'Ch.4 green LED on to show data run ended (optional)					
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