New Callibration has been saved
Restart in Measure

EC/TDS Monitor (Console Mode) Ver 0.6b
Defaults - Calibration @: 1.5EC - Temp Coefficient: 0.019 - TDS/ppm Conversion factor: 0.7
Cell Constant: 3.52427 Resistance R1/Ra: 470 / 36ohms - Cell Voltage: 3.28 Vdc
Temperature is in Degrees Celcius

Waiting for Keypress (C or M)

Measure

Volt drop:1.031 Temps: 23.25 / 23.25 Resistance: 195.847 Ohms EC:1.50 S Concentration: 1049 ppm/TDS '1.5EC standard
Volt drop:1.030 Temps: 23.25 / 23.25 Resistance: 195.671 Ohms EC:1.50 S Concentration: 1050 ppm/TDS 'as used for
Volt drop:1.031 Temps: 23.25 / 23.25 Resistance: 195.847 Ohms EC:1.50 S Concentration: 1049 ppm/TDS 'calibration
'
Volt drop:2.012 Temps: 23 / 23.25 Resistance: 766.718 Ohms EC:0.38 S Concentration: 269 ppm/TDS 'Filtered
Volt drop:2.034 Temps: 23 / 23.25 Resistance: 789.868 Ohms EC:0.37 S Concentration: 261 ppm/TDS 'tap water
Volt drop:2.060 Temps: 23 / 23.25 Resistance: 818.633 Ohms EC:0.36 S Concentration: 252 ppm/TDS
'
Volt drop:0.741 Temps: 23.25 / 23.25 Resistance: 111.777 Ohms EC:2.63 S Concentration: 1838 ppm/TDS '3.00EC standard
Volt drop:0.738 Temps: 23.25 / 23.25 Resistance: 110.809 Ohms EC:2.65 S Concentration: 1854 ppm/TDS
Volt drop:0.737 Temps: 23.25 / 23.25 Resistance: 110.533 Ohms EC:2.66 S Concentration: 1859 ppm/TDS
Volt drop:0.734 Temps: 23.25 / 23.25 Resistance: 109.982 Ohms EC:2.67 S Concentration: 1868 ppm/TDS
>

'EC Measurment for Micromite
'M Ogden April 2017
'http://www.codenquilts.com.au
'Based on Arduino code by Michael Ratcliffe

'Versions
'v0.5b Console ver Cal, Measure

'Options
option explicit
option default Integer

'Contants
const Sver$="Ver 0.6b"
'Global variables
dim float CalibrationEC
dim float TempCoef
Dim Float PPMconversion
dim R1 'resistance of EC Series resistor
dim Ra 'resistance of powering pins avg from Microchip data
dim float Vin
dim float K 'Cell Constant for Measurements, calculated in the Calibration routine
dim Float EC
dim float EC25
dim float Vdrop
dim float Rc


Dim ECPin=4 'EC input
dim ECGround=17 'EC Ground pin
dim ECpower=18 'EC Power pin
dim TrPin=16 'Temperature pin
Dim RV 'Reverse voltage period value to Cell for Depolarisation
Dim TempStart as float
dim TempFinish as float
Dim Keyin$
Dim ppm,backup,exittask,mode

'Define I/O
Setpin ECpin,ain
setpin ECGround,dout
setpin ECPower,dout

'intialise I/O
pin(ECGround)=0
pin(ECPower)=0


'init Modules
'Initialise Arrays



' Restore the settings. If this is the first time set the defaults
Var Restore
cls
Text MM.HRes/2, MM.VRes/2, "INITIALISE", CM, 1,2, RGB(white)
pause 1000

'****************************************************************************
'To restore defaults touch the centre of the LCD "INITIALISE" during startup.
'****************************************************************************
if Touch(x) <> -1 Then
cls
backup=0
Text MM.HRes/2, MM.VRes/2, "DEFAULTS RESTORED", CM, 1, 2, RGB(white)
end if
pause 1000

If backup = 0 Then
backup=1
rv=125 'Reverse voltage period value to Cell for Depolarisation
CalibrationEC=1.5 'standard calibration
TempCoef=0.019 'temp coefficient for Hydroponics solutions
PPMconversion=0.7 'Tranchen [Australia] PPM conversion value: 0.7
R1=470 'resistance of EC Series resistor
Ra=36 'resistance of powering pins avg from Microchip data
Vin=3.28 'Open circuit voltage reading of Cell
K=3.43 'Cell Constant for "RCA type plug" as Cell @ 1.5 EC
Var Save backup, CalibrationEC, PPMConversion,TempCoef,R1,Ra,Vin,K
EndIf

'interupts
'Settick 1000 ,T1,1 'establish seconds "Tick Timer"
' now draw the display
'init variables
R1=R1+Ra
mode=0 '0 for Console, 1 for LCD (not implemented)


cls
'*** start main program loop

do
consolemode
loop
'***** End main program loop
End If
end

'**************** sub routines *********************

'T1 - 1second Tick interrupt
'set up some time flags

sub ConsoleMode

Do
print ""
Print "EC/TDS Monitor (Console Mode) ";Sver$
Print "Defaults - Calibration @:";CalibrationEC;"EC - Temp Coefficient:";TempCoef;" - TDS/ppm Conversion factor:";ppmconversion
print "Cell Constant K:";k;" Resistance R1/Ra:";r1-Ra;" /";Ra;" ohms";" - Cell Voltage:";Vin;" Vdc"
Print "Temperature is in Degrees Celcius"
Print ""
Print "Waiting for Keypress (C or M)"
pause 500
DO
keyin$ = INKEY$
LOOP UNTIL keyin$ <> ""
'print "Keyin:";keyin$
If UCase$(keyin$)="C" Then
print
Print "Calibrate, press S (once) to save new Calibration"
Calibrate
elseif UCase$(keyin$)="M" then ' just measure
Print
Print "Measure"
Do
GetEC
printReadings
pause 10000
Loop
EndIf
Loop
end sub

sub PrintReadings 'Console
print "Volt drop:";str$(vdrop,1,3);
print " Temps:";tempstart;" / ";tempfinish;
print " Resistance:";str$(RC,4,3);" Ohms";
Print " EC:";str$(EC25,1,2);" S";
print " Concentration:";ppm;" ppm/TDS"
end Sub

sub GetEC 'Read the EC Cell
tempstart=tempr(TRpin) 'get start temperature
vdrop=EC_Cell() 'read EC cell
' Calculate R relating to Calibration fluid)
Rc=(Vdrop*R1)/(Vin-Vdrop)
Rc=Rc-Ra
EC=1000/(Rc*K)
'compensate for temperature
EC25=EC/(1+(tempcoef*(tempstart-25)))
ppm=(EC25)*(ppmconversion*1000)
end sub

function EC_Cell() as float
local raw as float
EC_Cell=9 'EC can't be 9 so this signals error
pin(ECpower)=1 'power on EC probe
raw=pin(ecpin)
pin(ECPower)=0 'power off EC probe
pin(ECGround)=1 'reverse voltage to minimise polarisation
pause RV 'pause at reverse polarity
pin(ECGround)=0
if raw<>0 then EC_Cell=raw
end function


Sub Calibrate
exittask=0
do
tempstart=tempr(TRpin) 'get start temperature
vdrop=EC_Cell() 'read EC cell
tempfinish=tempr(TRpin) 'get finish temperature
'compensate for temperature
EC=calibrationEC*(1+(tempcoef*(tempfinish-25)))
' Calculate R relating to Calibration fluid)
Rc=(Vdrop*R1)/(Vin-Vdrop)
Rc=Rc-Ra
K=1000/(Rc*EC)
print "Volt drop:";str$(vdrop,1,3);
print " Temps:";tempstart;" / ";tempfinish;
print " Resistance:";str$(RC,4,3);" Ohms";
Print " EC:";str$(CalibrationEC,1,2);" S";
print " Cell Constant K:";str$(K,1,2)
If tempstart=tempfinish then
'print "Safe to use the K value in main code"
else
print "Error - Wait for temperature to settle "
end if
pause 10000
keyin$ = INKEY$
If UCase$(keyin$)="S" Then
print "New Callibration has been saved"
print "Restart in Measure "
var save K
exittask=1
end if
Loop until exittask=1
End Sub