'PLOT-DIGOO/BME280    Greg Yaxley - "paceman" @ thebackshed.com forum.
 'May 2020 MMBasic Ver 5.05.02
 'See http://www.thebackshed.com/forum/forum_posts.asp?TID=10464&KW=digoo&PN=1&TPN=5
 '----------------------------------------------------------------------------------
 'Scrolling time-plot for oC & %RH data transmitted from two 433MHz Digoo R8S sensors
 'and a wired BME280 (I2C protocol) pressure sensor.
 'Plots 7hrs of data on a DDS1963 4.3" screen, then scrolls in hourly increments.
 'Data is noise-checked using rolling average of five valid readings, +/- a range.
 'Auto-scaling implemented on BME280 pressure, but not Digoo temperature & humidity.
 '
 'Acknowledgements:
 '1. TBS forum "TassieJim" (Jim Hiley) method to read the Digoo 433 MHz transmission at:
 '"http://www.thebackshed.com/forum/forum_posts.asp?TID=10317&KW=decoding+433&PN=1&TPN=2"
 '2. TBS forum "disco4now" (Gerry Alardice) method to decode it at:
 '"http://www.thebackshed.com/forum/forum_posts.asp?TID=10335&KW=digoo"
 '3. TBS forum "matherP" (Peter Mather) method to read BME280 wired I2C pressure sensor:
 '"http://www.thebackshed.com/forum/forum_posts.asp?TID=8362&KW=bme280"
 '4. TBS forum "MicroBlocks" ( ) for day-of-week code.
 '----------------------------------------------------------------------------------
 option autorun on
 Option Explicit
 Option Default NONE
'-----------------------------------------------------------------------------------
 const blue=rgb(blue),green=rgb(green),yellow=rgb(yellow),red=rgb(red),black=rgb(black)
 const cyan=rgb(cyan),magenta=rgb(magenta),BRGRAY=rgb(100,100,100),LTGRAY=rgb(60,60,60)
 
 Dim tick%,tock%,code$
 Dim channel$,relhumid$,temp$,curdate$,curtime$,dattime$,info$,oldresult$
 Dim integer gridtop,plotstart,BMEcalled,xposn,yposP,scrolling
 Dim float topP=30.4,botP=29.6,topT=40,topR=100
 Dim integer cn1,cn2,cnP,noise,Ch1TN,Ch1RN,Ch2TN,Ch2RN
 Dim float Tch1(7),Rch1(7),Tch2(7),Rch2(7),Press(7),pressure
 
 const highrestimer = 49, receiveblip = 31  'on MM+ pins 49&31.
 PWM 1,10000,50 'PWM1A pin 48 on MM+, & counting pin 49 for the high resol'n timer.
 SETPIN highrestimer, CIN  'input (counting) pin for the high resolution timer.
 SETPIN receiveblip, INTL, blip  'input (receive) pin for data out (DO) of the 433MHz
 'receiver module. It triggers on high to low transition. Pin used must be 5V tolerant.
 'Each Digoo unit transmits oC/%RH data pair at ~50 sec intervals.
 
'=======================================================================================  
'  BME280 Declarations  - Peter Mather
'=======================================================================================
 
 const BME280_ADDRESS                    = &H76  'was 77 - changed to 76 for GY module
 const BME280_REGISTER_T1                = &H88
 const BME280_REGISTER_P1                = &H8E
 const BME280_REGISTER_H1                = &HA1
 const BME280_REGISTER_H2                = &HE1
 const BME280_REGISTER_CHIPID            = &HD0
 const BME280_REGISTER_CONTROLHUMID      = &HF2
 const BME280_REGISTER_CONTROL           = &HF4
 const BME280_REGISTER_PRESSUREDATA      = &HF7
 const BME280_REGISTER_TEMPDATA          = &HFA
 const BME280_REGISTER_HUMIDDATA         = &HFD
'  
 dim integer s16=&HFFFFFFFFFFFF0000 , s16b=&H8000
 dim integer s12=&HFFFFFFFFFFFFF000 , s12b=&H800
 dim integer s8= &HFFFFFFFFFFFFFF00 , s8b=&H80
'        
 DIM INTEGER T1,T2,T3     'uint16_t, int16_t, int16_t
 DIM INTEGER P1,P2,P3,P4,P5,P6,P7,P8,P9    'uint16_t, 8 x int16_t
 DIM INTEGER H1,H2,H3,H4,H5,H6     'uint8_t, int16_t , uint8_t, int16_t, int16_t, int8_t
'
 dim INTEGER t_fine  'stores accurate temp reading from temp conversion for use in
'pressure and humidity conversions

'=======================================================================================
' Main
'=======================================================================================
 
 cls
 rtc gettime
 drawgrids
 blit read #1,mm.hres-90,60,60,200   'store the blank scrolling area of the screen.
 bme280_init           'must be run before pressure or humidity
 settick 30000,BME     'read presuure every 30 secs.
 DO
 loop
'=======================================================================================
'BME280 Functions & Subroutines  -  Peter Mather
'=======================================================================================

Sub BME
 BMEcalled = 1      'flag used in plotdata sub to ignore any first bad pressure reading.
 print str$(bme280_read_temp(),2,2),"  ";     'DEBUG print BME temperature to console
 print str$(bme280_read_humidity(),2,2);      'DEBUG print BME %RH to console
 pressure = bme280_read_pressure()*0.029531   'convert mbar to "Hg
 Print "   ",str$(pressure,2,2)               'DEBUG print BME pressure to console
 text 312,30,str$(pressure,2,2),,2,,BLUE      'display pressure in screen box area
 gui beep 20            '20msec buzzer beep (on pin 21) to announce new pressure data.
END sub
 
'=======================================================================================
function  bme280_read_temp() as float
 local integer var1,var2,adc_T
 local adc%(2)
 i2c write BME280_ADDRESS,1,1,BME280_REGISTER_TEMPDATA
 i2c read BME280_ADDRESS,0,3,adc%()
 adc_T=((adc%(0)<<16) OR (adc%(1)<<8) or adc%(2))>>4
 var1  = ((((adc_T>>3) - (T1 <<1))) * T2) \ q(11)
 var2  = (((((adc_T>>4) - (T1)) * ((adc_T\ q(4)) - (T1))) \ q(12)) * (T3)) \ q(14)
 t_fine = var1 + var2
 bme280_read_temp = ((t_fine * 5 + 128) \ q(8))/100.0
end function
'
function  bme280_read_pressure() as float
 local integer var1, var2, adc_P, p
 local adc%(2)
 i2c write BME280_ADDRESS,1,1,BME280_REGISTER_PRESSUREDATA
 i2c read BME280_ADDRESS,0,3,adc%()
 adc_P=((adc%(0)<<16) OR (adc%(1)<<8) or adc%(2))>>4
 var1 = t_fine - 128000
 var2 = var1*var1*P6
 var2 = var2 + ((var1*P5)<<17)
 var2 = var2 + (P4<<35)
 var1 = ((var1*var1*P3)\q(8))+((var1*P2)<<12)
 var1 = ((1<<47)+var1)*P1\q(33)
 if var1 = 0 THEN
   bme280_read_pressure = 0  ' avoid exception caused by division by zero
   exit function
 endif
 p = 1048576 - adc_P
 p = (((p<<31) - var2)*3125) \ var1
 var1 = (P9 * (p\ q(13)) * (p\ q(13))) \ q(25)
 var2 = (P8 * p) \ q(19)
 p = ((p + var1 + var2) \ q(8)) + (P7<<4)
 bme280_read_pressure = p/25600.0
end function
'  
function  bme280_read_humidity() as float
 local integer v_x1,adc_H
 local adc%(1)
 i2c write BME280_ADDRESS,1,1,BME280_REGISTER_HUMIDDATA
 i2c read BME280_ADDRESS,0,2,adc%()
 adc_H=(adc%(0)<<8) or adc%(1)
 v_x1 = t_fine - 76800
 v_x1=(((((adc_H<<14)-((H4)<<20)-(H5*v_x1))+16384)\ q(15))*(((((((v_x1*H6)\ q(10))*(((v_x1*H3)\ q(11))+32768))\ q(10))+2097152)*H2+8192)\ q(14)))
 v_x1 = (v_x1 - (((((v_x1 \ q(15)) * (v_x1 \ q(15))) \ q(7)) * (H1)) \ q(4)))
 if v_x1< 0 then v_x1 = 0
 if v_x1 > 419430400 then v_x1= 419430400
 bme280_read_humidity = (v_x1\ q(12)) / 1024.0
end function
'
sub bme280_init
 local i%,cal%(17)
 i2c open 400,1000 '400KHz bus speed
 i2c write BME280_ADDRESS,1,1,BME280_REGISTER_CHIPID
 i2c read BME280_ADDRESS,0,1,i%
 if i%<>&H60 then print "Error BME280 not found"
 '  
 i2c write BME280_ADDRESS,1,1,BME280_REGISTER_T1
 i2c read BME280_ADDRESS,0,6,cal%()
 T1=cal%(0) OR (cal%(1)<< 8)
 T2=cal%(2) OR (cal%(3)<< 8):   if T2 and s16b then T2=T2 OR s16 'sign extend if req'd
 T3=cal%(4) OR (cal%(5)<< 8):   if T3 and s16b then T3=T3 OR s16
 '  
 i2c write BME280_ADDRESS,1,1,BME280_REGISTER_P1
 i2c read BME280_ADDRESS,0,18,cal%()
 P1=cal%(0) OR (cal%(1)<<8)
 P2=cal%(2) OR (cal%(3)<<8):   if P2 and s16b then P2=P2 OR s16 'sign extend if required
 P3=cal%(4) OR (cal%(5)<<8):   if P3 and s16b then P3=P3 OR s16
 P4=cal%(6) OR (cal%(7)<<8):   if P4 and s16b then P4=P4 OR s16
 P5=cal%(8) OR (cal%(9)<<8):   if P5 and s16b then P5=P5 OR s16
 P6=cal%(10) OR (cal%(11)<<8):   if P6 and s16b then P6=P6 OR s16
 P7=cal%(12) OR (cal%(13)<<8):   if P7 and s16b then P7=P7 OR s16
 P8=cal%(14) OR (cal%(15)<<8):   if P8 and s16b then P8=P8 OR s16
 P9=cal%(16) OR (cal%(17)<<8):   if P9 and s16b then P9=P9 OR s16
 '  
 i2c write BME280_ADDRESS,1,1,BME280_REGISTER_H1
 i2c read BME280_ADDRESS,0,1,H1
 i2c write BME280_ADDRESS,1,1,BME280_REGISTER_H2
 i2c read BME280_ADDRESS,0,7,cal%()
 H2=cal%(0) OR (cal%(1)<< 8):   if H2 and s16b then H2=H2 OR s16 'sign extend if req'd
 H3=cal%(2)
 H6=cal%(6):   if H6 and s8b then H6=H6 OR s8 'sign extend if required
 H4=(cal%(3)<<4) OR (cal%(4) and &H0F): if H4 and s12b then H4=H4 OR s12 'sign extend if req'd
 H5=(cal%(5)<<4) OR (cal%(4)>>4):  if H5 and s12b then H5=H5 OR s12
 '  
 i2c write BME280_ADDRESS,0,2,BME280_REGISTER_CONTROLHUMID,&H05 '16x oversampling humidity
 i2c write BME280_ADDRESS,0,2,BME280_REGISTER_CONTROL,&HB7      '16x oversampling pressure/temp, normal mode
end sub
'
function q(x as integer) as integer  'returns 2 raised to the power
 q=(1<<x)
End Function

'=======================================================================================
'                  Digoo Sensor - 433MHz decode and display.
'=======================================================================================
SUB blip                      'detects & reads Digoo 433MHz transmissions.
 tock% = tick%
 tick% = PIN(highrestimer)   'read the high resolution timer counts.
 select case tick%-tock%     'build the transmitted code bit by bit.
   case > 80
     if len(code$)=37 and left$(code$,1)="1" then getdata    'valid data.
     code$ =""
   case > 35
     code$ = code$ +"1"
   case > 15
     code$ = code$ +"0"
   case else                 'not valid transmission. This 'blip' is noise.
     code$ =""
 END select
END SUB
 '--------------------------------------------------
sub getdata                          'decodes the oC & %RH Digoo transmission.
 if mid$(code$,17,1)="0" then       '0 in bit 17 means a +ve temp.
   temp$ =STR$(VAL("&B"+mid$(code$,17,12))/10,2,1) 'rec'd oC is 0.1 res'n x10 so needs /10.
 else
   temp$ = "-" +STR$(VAL("&B"+reverse(mid$(code$,17,12),12))/10,2,1)  'temp is -ve.
 endif
 relhumid$ = STR$(VAL("&B"+mid$(code$,30,7)))      'rec'd %RH is whole numbers.
 channel$ = STR$(VAL("&B"+mid$(code$,15,2))+1)
 curdate$ = date$: curtime$ = time$
 dattime$ = right$(curdate$,2)+mid$(curdate$,4,2)+left$(curdate$,2)+" "+left$(curtime$,5)
 
 info$ = dattime$ + channel$ + temp$ + relhumid$
 if info$ = oldresult$ then exit sub  'removes the Digoo 'triple' transmission.
 oldresult$ = info$           'holds current result for above comparison.
 plotdata                     'valid information (data), so display it.
end sub
 '----------------------------------------------------
function reverse(in$,len%)as string   'inverts binary string - credit to MikeO at TBS.
 local x%
 for x%=1 to len%
   if mid$(in$,x%,1)="1" then
     reverse = reverse+"0"
   else
     reverse = reverse+"1"
   end if
 next x%
end function
 '----------------------------------------------------
sub drawgrids
 cls
 FONT #2          '12x20 NB: all fonts have chr(96) "`" replaced by degrees symbol.
 text 0,0,"  Date  Time  Ch  `C  %RH  Hg    Noise",,2
 gridtop = 3*mm.fontheight   'gridtop = top of y scales. Allows 3 rows of Font #2.
 box 0,0,mm.hres,20: box 0,0,mm.hres,gridtop     'boxes for heading & current data.
 font #1          '8x13
 timescale        'Display the timescale
 tempRHscales     'Display the temperature & %RH scales
 pressurescale    'Display the BME280 pressure scale
end sub
 '----------------------------------------------------
sub timescale        'Vertical grid (X axis) & Timescale (24hr format).
 local integer j,basehour
 static integer nextbasehour   'STATIC holds variable between SUB calls.
 
 'basehour' is the start time (hour) for the X grid time-scale. Scrolling starts when
 'the grid end is reached and a 'scrolling' flag is set in the 'scroll' subroutine.
 'The new basehour is then advanced one hour from the previous and stored in STATIC
 'variable 'nextbasehour' ready for the next scroll.
 
 if not scrolling then basehour = val(left$(time$,2)+"00") else basehour = nextbasehour
 nextbasehour = basehour +100          'advance nextbasehour if scrolling.
 if nextbasehour = 2400 then  nextbasehour =0   'test for midnight, reset if yes.
 
 for j=30 to MM.HRES step 60           '60 mins/gridline --> ~1 result per display line.
   if basehour = 2400 then  basehour =0       'test for midnight
   line j,gridtop,j,mm.vres,,BRGRAY           'one vertical grid line per hour.
   text j,mm.vres,str$(basehour,4,0,"0"),CB   'hour scale, 24-hour format, centered.
   basehour = basehour+100             'increments the hour scale in 24-hour format.
 next j
 dayndate                              'display day & date at centre base of screen.
 plotstart = val(mid$(time$,4,2)) +30  'mins past-the-hour to start (sync) the X plot.
 if scrolling then  plotstart = mm.hres-90  're-commence plotting in scrolling area.
 '======
 'if scrolling then  plotstart = mm.hres-90 else plotstart = mm.hres-32 'testing only
 '======
 timer=0   'zero elapsed-time base for X-axis data plot pos'n. in 'plotdata' sub.
end sub
 '----------------------------------------------------
SUB tempRHscales      'Draw Y-axis horiz. grid & oC/%RH fixed scales
 local integer j,t,r
 t = topT: r = topR
 'Horizontal grid lines - major and minor using MOD operator.
 for j=60 to mm.vres-10 step 25   '25lines=5oC 5lines/oC & 25lines=10%RH 2.5lines/%RH
   if j mod 2 then line 0,j,mm.hres,j,,LTGRAY else line 0,j,mm.hres,j,,BRGRAY
   text 0,j,str$(t,2,0," "),LM,,,yellow       'oC scale at left
   text mm.hres,j,str$(r),RM,,,green          '%RH scale at right
   t =t-5: r =r-10               'step oC & %RH scales by 5oC and 10%RH respectively.
 next j
end sub
 '----------------------------------------------------
sub pressurescale                     'Data from BME280 sensor. This scale autoranges.
 local integer j: local float k
 k = topP-0.1                        'scale starts 0.1 "Hg from gridtop
 for j= 85 to 235 step 50            'gives 0.1 "Hg = 25 pixels
   text 36,j,str$(k,2,1),LM,,,BLUE   'display scale within grid at left.
   k = k-0.2
 next  j
end sub
 '------------------------------------------------------------
sub plotdata                          'another Digoo oC/%RH data set coming in.
 local float flT,flRH
 flT =val(temp$):  flRH =val(relhumid$)  'convert to integer for noisecheck & plot.
 
 if flRH > 99.0 then flRH = 99.0     'DEBUG stops any over-scale RH stuffing up display.
 if flRH = 99.0 then relhumid$ = "99" 'DEBUG stops any over-scale RH stuffing up display.
 
 'Noisecheck data then display & plot on grid. Scroll at grid end.
 xposn = plotstart + (timer/60000)   'start posn + elapsed mins since grid draw or scroll.
 if xposn => mm.hres-30 then scroll  'if reached end of grid, start scrolling.
 
 If cn1=6 Then cn1=5     'Reset rolling average noisecheck data array counters to 5
 If cn2=6 Then cn2=5     'after first 6 have been built up. After that, number 6 is
 If cnP=6 Then cnP=5     'then always the current result.
 
 if channel$ ="1" then                'this is Ch1 data.
   cn1 = cn1+1                        'array element counter for Ch1 noisecheck arrays.
   Tch1(cn1)= flT:  Rch1(cn1)= flRH   'build up Ch1 noisecheck array elements.
   if cn1 =6 then                     'when six Ch1 array elements have been filled.
     text 8,20,dattime$ +"  "+ channel$,,2   'display date/time of current Ch1 data.
     print "                       ",Tch1(cn1)," ",Rch1(cn1) 'DEBUG Digoo Ch1 data
     noisecheck(Tch1(),5)             'check if Ch1 temp. is noise. Limits +/- 5oC.
     if noise then
       Ch1TN = Ch1TN +1                         'Update Ch1 temperature noise count.
       text 390,20,Str$(Ch1TN,2,0),,2,,yellow   'display it in textbox.
     else
       text 206,20,temp$,,2,,yellow   'display temperature in TCh1 textbox
       Pixel xposn,260-5*flT,yellow   'and plot using base & slope of temp. scale.        
     endif
     noisecheck(Rch1(),15)            'check if Ch1 %RH is noise. Limits +/- 10%.
     if noise then
       Ch1RN = Ch1RN +1               'Update Ch1 %RH noise count.
       text 430,20,Str$(Ch1RN,2,0),,2,,GREEN     'display it in textbox
     else
       text 270,20,relhumid$,,2,,green   'display %RH in RCh1 textbox & then plot
       Pixel xposn,260-(2.5*(flRH-20)),green  'using base, slope and offset of %RH scale.
     endif
   endif
   
 else                                 'this is Ch2 data.
   cn2 = cn2+1                        'counter for Ch2 rolling average noisecheck array.
   Tch2(cn2)= flT:   Rch2(cn2)= flRH  'build up Ch2 noisecheck array elements.
   If cn2 =6 Then                     'when six array elements have been filled
     text 8,39,dattime$ +"  "+ channel$,,2     'display date/time of current Ch2 data.
     print "                                  ",Tch2(cn2),"  ",Rch2(cn2) 'DEBUG Ch2 data
     noisecheck(Tch2(),5)             'check if Ch2 temp. is noise. Limits +/- 5oC.
     if noise then
       Ch2TN = Ch2TN +1               'update Ch2TN noisecount
       text 390,39,Str$(Ch2TN,2,0),,2,,MAGENTA    'display noisecount in TCh2 textbox
     else
       text 206,39,temp$,,2,,MAGENTA      'display temperature in TCh2 textbox
       Pixel xposn,260-5*flT,magenta      'and plot using base & slope of temp. scale.
     endif
     noisecheck(Rch2(),10)                'check if Ch2 %RH is noise. Limits +/- 15%.
     if noise then
       Ch2RN = Ch2RN +1                   'update Ch2RN noisecount
       text 430,39,Str$(Ch2RN,2,0),,2,,red      'display noisecount in RCh2 textbox
     else
       text 270,39,relhumid$,,2,,red      'display %RH in RCh2 textbox & then plot
       Pixel xposn,260-(2.5*(flRH-20)),red  'using base, slope and offset of %RH scale.
     endif
   endif
 endif
 gui beep 40                              'buzzer beep (pin 21) to announce new data.
 
 'Also, noisecheck BME280 presssure data, check within-scale then display & plot.
 if BMEcalled then                        'ignores very first pressure reading
   cnP = cnP+1                            'counter for rolling average noisecheck array.
   press(cnP) = pressure                  'build up noisecheck array.
   If cnP =6 Then noisecheck(press(),0.1) 'check if pressure reading is noise.
   if noise then
     text 320,30,Str$("Noise",2,2),,2,,BLUE  'DEBUG display "Noise" in pressure textbox
   else
     if pressure > topP-0.02 then         'pressure over-scale? Update limits &
       topP= topP+0.1: botP= botP+0.1: pressurescale  'display new pressurescale.
       triangle xposn,80,xposn+4,72,xposn-4,72,blue  'Draw indicative down-arrow.
     endif
     if pressure < botP+0.02 then         'pressure under-scale? Update limits &
       topP= topP-0.1: botP= botP-0.1: pressurescale  'display new pressurescale.
       triangle xposn,237,xposn+4,245,xposn-4,245,blue  'Draw indicative up-arrow.
     endif
     Text 312,30,Str$(pressure,2,2),,2,,BLUE    'display pressure in textbox
     yposP = 260-(250*(pressure-botP))     'base & slope of pressure scale
     pixel xposn,yposP,BLUE                'plot pressure; 1"Hg pressure =250 pixels.
   endif
 endif
end sub
'---------------------------------------------------
sub noisecheck(param() As float,limit As float) As integer   'Simple rolling average.
 Local integer i,m
 Local float sum,rollave
 
 noise =0                       'reset flag.
 For i = 1 To 5
   sum = sum + param(i)
 Next i
 rollave = sum/5                'calc. rolling average of first 5 array elements.
 If param(6)> rollave+limit Or param(6)< rollave-limit Then noise =1  'test current result.
 if noise then                                   'DEBUG
   line xposn,134,xposn,142                      'DEBUG mark display when noise occurred.
   text xposn,150,Str$(param(6),2,2),ctv,,,red   'DEBUG display param(6)vertically.
   text xposn,65,Str$(rollave,2,2),ctv,,,cyan    'DEBUG display rollave vertically.
 endif                                           'DEBUG
 If noise Then Exit Sub         'if noise, exit with flag set.
 For m = 1 To 6                 'if not noise, shuffle array back one. This drops 1st array
   param(m) = param(m+1)        'element thus the current data, param(6), is now param(5).
 Next m
End Sub
'---------------------------------------------------
sub scroll
 local integer b
 text mm.hres/2,mm.vres-mm.fontheight,"                  ",CB   '18 spaces clears dayndate.
 scrolling = 1                  'set scrolling flag for timescale subroutine.
 blit 78,260,18,260,13,12       'move second leftmost hours timescale to leftmost.
 for b = 90 to 390 step 60      'move main grid/data display left in 1hr segments....
   blit b,58,b-60,58,60,213     'from below data box to bottom of screen.
 next b
 blit write #1,mm.hres-90,60,60,200   'overwrite last hour with stored clean screen.
 timescale                      'update & display the timescale.
 pressurescale                  're-display pressure scale; it's been blitted offscreen.
 xposn =mm.hres-90              'reset plot pos'n to start of scroll area.
end sub
 '---------------------------------------------------
sub dayndate        'day-of-week code thanks to "MicroBlocks" at TBS forum.
 local integer year,month,day,dayofweek,a,m,y
 local string DOW$(6) length 3 = ("Sun","Mon","Tue","Wed","Thu","Fri","Sat")
 local string dispdayndate$
 curdate$ = date$
 Year=VAL(MID$(curdate$,7,4)): Month=VAL(MID$(curdate$,4,2)): Day=VAL(MID$(curdate$,1,2))
 a = int((14-month)/12)
 m = month + 12*a - 2
 y = year - a
 DayOfWeek = (day+y+int(y/4)-int(y/100)+int(y/400)+int(31*m/12))mod 7
 dispdayndate$ = DOW$(DayOfWeek)+" "+curdate$
 text mm.hres/2,mm.vres-mm.fontheight,"<-- "+ dispdayndate$,CB   'DOW & date on timescale
end sub
 '---------------------------------------------------