'  LEDtest2
'
'  Controls the adafruit 1.2" LED backpack card


'  constants and codes for numbers 0-9
dim num(10) = 0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f
ht15k33 = 0xe0		' address of adafruit backpack card - really!
osc_on  = 0x21		' code to turn oscillator on
disp_on = 0x81		' code to turn display on
disp_off = 0x80		' code to turn display off
bright  = 0xef		' code for max brightness
z$ = chr$(00)		' code for a blank digit/colon

' initialize the I2C bus on the EXsbc1 card
i2cinit(100000)		' initialize the I2C bus
i2ctime(10)

' initialize the backpack card
c$=""
i2cwr(0xe0,0x21,c$,0)	' trick to send <adr> <cmd> only
delay(100)
i2cwr(0xe0,0xef,c$,0)
delay(100)
i2cwr(0xe0,0x81,c$,0)
delay(100)

print "Input a 1-4 digit number: ";
INPUT number 
repeat
	gosub display4dig:
	print "Input a 1-4 digit number (<0 to quit): ";
	INPUT number 
until number<0
print ""
print "Count-up display, max count = ";
input maxcnt
maxcnt=max(maxcnt,1)
for k=0 to maxcnt
	number=k
	gosub display4dig:
	delay(250)
next k
end

' subroutine to display up to 4 digits with leading zero blanking
' call with an integer in the variable 'number'
display4dig:
	d1=int(number/1000)
	if d1>0 then
		d1$=chr$(num(d1+1))
	else
		d1$=chr$(0x00)
	endif

	d2=int((number-d1*1000)/100)
	if d2>0 or number>99 then
		d2$=chr$(num(d2+1))
	else
		d2$=chr$(0x00)
	endif

	d3=int((number-d1*1000-d2*100)/10)
	if d3>-1 and number>9 then
		d3$=chr$(num(d3+1))
	else
		d3$=chr$(0x00)
	endif

	d4=int((number-d1*1000-d2*100-d3*10))
	d4$=chr$(num(d4+1))		' always display 0 or more
	
	i2cwr(0xe0,0x00,d1$,1)
	i2cwr(0xe0,0x02,d2$,1)
	i2cwr(0xe0,0x04,z$,1)	' clear dp's
	i2cwr(0xe0,0x06,d3$,1)
	I2CWR(0Xe0,0x08,d4$,1)
return